/* ================================================================
   PP Notes — Design System CSS
   Physics Pathway | Dark + Light Theme
   ================================================================ */

/* ---- Theme Variables ---- */
:root, :root[data-theme="light"] {
    --pp-bg:            #FAFAFA;
    --pp-surface:       #FFFFFF;
    --pp-text:          #111827;
    --pp-text-secondary:#4B5563;
    --pp-text-muted:    #6B7280;
    --pp-border:        #E5E7EB;
    --pp-border-subtle: rgba(229, 231, 235, 0.5);
    --pp-purple:        #7C3AED;
    --pp-purple-deep:   #5B21B6;
    --pp-purple-accent: #6D28D9;
    --pp-purple-light:  #F5F3FF;
    --pp-purple-glow:   rgba(124, 58, 237, 0.06);
    --pp-teal:          #0D9488;
    --pp-teal-light:    rgba(13, 148, 136, 0.04);
    --pp-red:           #DC2626;
    --pp-red-light:     rgba(220, 38, 38, 0.04);
    --pp-green:         #059669;
    --pp-green-light:   #F0FDF4;
    --pp-amber:         #D97706;
    --pp-amber-light:   rgba(217, 119, 6, 0.04);
    --pp-topbar-bg:     rgba(250, 250, 250, 0.85);
    --pp-dot-color:     #D1D5DB;
    --pp-callout-def-text: #4a3875;
    --pp-callout-warn-text:#7f1d1d;
    --pp-callout-tip-text: #14532d;
    --pp-callout-syn-text: #115e59;
    --pp-shadow-card:   0 1px 3px rgba(0, 0, 0, 0.04), 0 4px 12px rgba(0, 0, 0, 0.02);
    --pp-shadow-card-hover: 0 2px 8px rgba(0, 0, 0, 0.06), 0 8px 24px rgba(0, 0, 0, 0.04);
    --pp-code-bg:       #F3F4F6;
}

:root[data-theme="dark"] {
    --pp-bg:            #0C0C10;
    --pp-surface:       #18181B;
    --pp-surface-raised:#27272A;
    --pp-text:          #F4F4F5;
    --pp-text-secondary:#A1A1AA;
    --pp-text-muted:    #71717A;
    --pp-border:        rgba(255, 255, 255, 0.08);
    --pp-border-subtle: rgba(255, 255, 255, 0.04);
    --pp-purple:        #A78BFA;
    --pp-purple-deep:   #C4B5FD;
    --pp-purple-accent: #8B5CF6;
    --pp-purple-light:  rgba(167, 139, 250, 0.05);
    --pp-purple-glow:   rgba(167, 139, 250, 0.08);
    --pp-teal:          #5EEAD4;
    --pp-teal-light:    rgba(20, 184, 166, 0.05);
    --pp-red:           #F87171;
    --pp-red-light:     rgba(248, 113, 113, 0.05);
    --pp-green:         #34D399;
    --pp-green-light:   rgba(52, 211, 153, 0.04);
    --pp-amber:         #FBBF24;
    --pp-amber-light:   rgba(251, 191, 36, 0.04);
    --pp-topbar-bg:     rgba(12, 12, 16, 0.88);
    --pp-dot-color:     rgba(255, 255, 255, 0.04);
    --pp-callout-def-text: #C4B5FD;
    --pp-callout-warn-text:#FCA5A5;
    --pp-callout-tip-text: #6EE7B7;
    --pp-callout-syn-text: #5EEAD4;
    --pp-shadow-card:   0 1px 3px rgba(0, 0, 0, 0.2), 0 4px 12px rgba(0, 0, 0, 0.15);
    --pp-shadow-card-hover: 0 2px 8px rgba(0, 0, 0, 0.3), 0 8px 24px rgba(0, 0, 0, 0.2);
    --pp-code-bg:       rgba(255, 255, 255, 0.04);
}

/* ---- Base ---- */
body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--pp-bg);
    background-image: radial-gradient(circle, var(--pp-dot-color) 0.8px, transparent 0.8px);
    background-size: 20px 20px;
    color: var(--pp-text);
    line-height: 1.7;
    font-size: 14px;
    margin: 0;
    transition: background-color 0.35s ease, color 0.35s ease;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

*, *::before, *::after { box-sizing: border-box; }

a { color: var(--pp-purple); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---- .pp-nav — Sticky frosted-glass navbar ---- */
.pp-nav {
    position: sticky; top: 0; z-index: 100;
    background: var(--pp-topbar-bg);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid var(--pp-border);
    padding: 12px 24px;
    display: flex; align-items: center; gap: 12px;
}
.pp-nav-logo {
    width: 28px; height: 28px; border-radius: 8px;
    background: linear-gradient(135deg, var(--pp-purple), var(--pp-teal));
    display: flex; align-items: center; justify-content: center;
    color: #fff; font-weight: 900; font-size: 12px;
}
.pp-nav-title {
    font-size: 11px; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.12em;
    color: var(--pp-purple);
}
.pp-nav-sep { color: var(--pp-text-muted); font-size: 12px; }
.pp-nav-sub { font-size: 12px; font-weight: 500; color: var(--pp-text-muted); }
.pp-nav-right { margin-left: auto; display: flex; align-items: center; gap: 8px; }

/* ---- Theme Toggle ---- */
.pp-theme-toggle {
    width: 36px; height: 20px; border-radius: 10px;
    background: var(--pp-border); border: none; cursor: pointer;
    position: relative; transition: background 0.3s;
}
.pp-theme-toggle::after {
    content: ''; position: absolute; top: 2px; left: 2px;
    width: 16px; height: 16px; border-radius: 50%;
    background: var(--pp-surface); transition: transform 0.3s;
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
[data-theme="dark"] .pp-theme-toggle { background: var(--pp-purple-accent); }
[data-theme="dark"] .pp-theme-toggle::after { transform: translateX(16px); }

/* ---- .pp-breadcrumb ---- */
.pp-breadcrumb {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 4px 12px; border-radius: 999px;
    border: 1px solid var(--pp-border);
    background: var(--pp-surface);
    font-size: 10px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.12em;
    color: var(--pp-purple); margin-bottom: 20px;
}
.pp-breadcrumb-dot {
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--pp-teal);
}

/* ---- .pp-header ---- */
.pp-header {
    margin-bottom: 32px;
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 16px;
    padding: 32px 36px 28px;
}
.pp-header h1 {
    font-size: 3rem; font-weight: 900;
    letter-spacing: -0.025em; line-height: 1.1;
    color: var(--pp-text); margin: 0 0 8px;
}
.pp-header h1 .highlight { color: var(--pp-purple); }
.pp-header .subtitle, .pp-header-subtitle {
    font-size: 16px; font-weight: 500;
    color: var(--pp-text-muted); margin: 0 0 12px;
}
.pp-header .meta {
    display: flex; gap: 16px; font-size: 12px;
    font-weight: 500; color: var(--pp-text-muted);
}
.pp-header .meta strong { color: var(--pp-purple); }

/* ---- Layout ---- */
.pp-layout {
    max-width: 1280px; margin: 0 auto;
    padding: 32px 24px 64px;
    display: flex; gap: 32px;
}
.pp-main { flex: 1; min-width: 0; max-width: 900px; }
@media (max-width: 1024px) {
    .pp-layout { padding: 24px 16px 48px; }
    .pp-header h1 { font-size: 2.2rem; }
}

/* ---- Content spacing ---- */
.pp-paragraph { margin: 14px 0; line-height: 1.7; }
.pp-bullets { margin: 14px 0; line-height: 1.7; padding-left: 22px; list-style: disc; }
.pp-bullets li { margin-bottom: 6px; }
.pp-note-card .pp-definition-card,
.pp-note-card .pp-tip-card,
.pp-note-card .pp-mistake-card,
.pp-note-card .pp-we-card,
.pp-note-card .pp-equation { margin: 16px 0; }
.pp-note-card .pp-examiner-card { margin: 8px 0; }
.pp-note-card .pp-diagram-placeholder { margin: 16px 0; }

/* ---- .pp-note-card ---- */
.pp-note-card {
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px; padding: 20px 28px;
    margin-bottom: 20px;
    transition: border-color 0.25s, box-shadow 0.25s;
    scroll-margin-top: 72px;
}
.pp-note-card:hover {
    border-color: rgba(124, 58, 237, 0.25);
    box-shadow: var(--pp-shadow-card);
}
.pp-note-card.active-note {
    border-color: rgba(124, 58, 237, 0.35);
    box-shadow: 0 0 0 3px var(--pp-purple-glow);
}

/* ---- Note Badge ---- */
.pp-note-badge {
    flex-shrink: 0; width: 30px; height: 30px;
    border-radius: 8px;
    display: inline-flex; align-items: center; justify-content: center;
    font-weight: 800; font-size: 12px; color: #fff;
    background: var(--pp-purple);
}

/* ---- Collapsible ---- */
details > summary { list-style: none; cursor: pointer; user-select: none; }
details > summary::-webkit-details-marker { display: none; }
details > summary::before {
    content: '\25B6'; display: inline-block; width: 1.2em;
    font-size: 0.7em; color: var(--pp-purple);
    transition: transform 0.2s; vertical-align: middle;
}
details[open] > summary::before { transform: rotate(90deg); }
.pp-note-card > details { border-left: none; padding-left: 0; margin-bottom: 0; }
.pp-note-card details details {
    border-left: 1px solid var(--pp-border);
    padding-left: 1rem; margin-bottom: 0.35rem; margin-left: 0.5rem;
}

/* ---- Note content area ---- */
.pp-note-content { margin-top: 16px; padding-left: 42px; }
.pp-note-content p {
    color: var(--pp-text-secondary);
    font-weight: 500; line-height: 1.7;
    margin: 0 0 12px;
}
.pp-note-content p strong { color: var(--pp-text); }
.pp-note-content .subsection-title {
    font-size: 15px; font-weight: 600; color: var(--pp-teal);
}

/* ---- Bullets ---- */
ul.pp-list { list-style: none; padding: 0; margin: 8px 0 12px; }
ul.pp-list li {
    position: relative; padding-left: 18px;
    margin-bottom: 5px; font-weight: 600; font-size: 13px;
    color: var(--pp-text-secondary);
}
ul.pp-list li::before {
    content: ''; position: absolute; left: 0; top: 9px;
    width: 5px; height: 5px; border-radius: 50%;
    background: var(--pp-purple);
}
ul.pp-list li strong { color: var(--pp-text); }

/* ---- Math Blocks ---- */
.pp-equation {
    background: var(--pp-purple-glow);
    border: 1px solid rgba(124, 58, 237, 0.12);
    border-radius: 8px; padding: 16px;
    margin: 12px 0; overflow-x: auto; text-align: center;
}
.pp-equation-vars {
    text-align: left; margin: 12px 0 0 0; padding: 0 0 0 20px;
    list-style: disc; font-size: 0.88rem; line-height: 1.7;
    color: var(--pp-text);
}
.pp-equation-vars li { margin: 2px 0; }
.pp-equation-vars strong { font-weight: 600; }

/* ---- Callouts ---- */
.pp-callout {
    border-radius: 0 10px 10px 0;
    padding: 16px 20px; margin: 12px 0;
    border-left: 3px solid;
}
.pp-callout .pp-callout-label {
    font-size: 0.68rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em;
    margin-bottom: 6px; display: flex; align-items: center; gap: 6px;
}
.pp-callout .pp-callout-text {
    font-weight: 500; line-height: 1.65; margin: 0;
}

/* Definition */
.pp-callout-definition {
    background: linear-gradient(135deg, var(--pp-purple-glow), transparent);
    border-left-color: var(--pp-purple);
}
.pp-callout-definition .pp-callout-label { color: var(--pp-purple); }
.pp-callout-definition .pp-callout-text { color: var(--pp-callout-def-text); }

/* Examiner Tip (green) */
.pp-callout-tip {
    background: var(--pp-green-light);
    border-left-color: var(--pp-green);
}
.pp-callout-tip .pp-callout-label { color: var(--pp-green); }
.pp-callout-tip .pp-callout-text { color: var(--pp-callout-tip-text); }

/* Common Mistake (red) */
.pp-callout-mistake {
    background: var(--pp-red-light);
    border-left-color: var(--pp-red);
}
.pp-callout-mistake .pp-callout-label { color: var(--pp-red); }
.pp-callout-mistake .pp-callout-text { color: var(--pp-callout-warn-text); }

/* Synoptic Link (teal) */
.pp-callout-synoptic {
    background: var(--pp-teal-light);
    border-left-color: var(--pp-teal);
}
.pp-callout-synoptic .pp-callout-label { color: var(--pp-teal); }
.pp-callout-synoptic .pp-callout-text { color: var(--pp-callout-syn-text); }

/* Severity badges for mistakes */
.pp-severity {
    display: inline-flex; padding: 2px 8px;
    border-radius: 4px; font-size: 9px; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.05em;
}
.pp-severity-high { background: rgba(220,38,38,0.12); color: var(--pp-red); }
.pp-severity-medium { background: rgba(180,83,9,0.12); color: var(--pp-amber); }
.pp-severity-low { background: rgba(13,148,136,0.12); color: var(--pp-teal); }

/* ---- .pp-mastery — Spec-point list (card container) ---- */
.pp-mastery {
    margin-bottom: 24px;
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px;
    padding: 20px 28px;
}
.pp-mastery-header {
    margin-bottom: 12px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--pp-border);
}
.pp-mastery-list {
    list-style: none; margin: 0; padding: 0;
}
.pp-mastery-item {
    display: flex; align-items: flex-start; gap: 10px;
    padding: 8px 4px; font-size: 13px; line-height: 1.5;
    color: var(--pp-text-secondary);
    border-bottom: 1px solid var(--pp-border-subtle);
}
.pp-mastery-item:last-child { border-bottom: none; }
.pp-mastery-item::before {
    content: ''; display: block; flex-shrink: 0;
    width: 6px; height: 6px; border-radius: 50%;
    background: var(--pp-purple); margin-top: 7px;
}
.pp-mastery-spec {
    font-size: 11px; font-weight: 700; color: var(--pp-text-muted);
    white-space: nowrap; min-width: 56px;
}
.pp-mastery-text {
    font-size: 13px; font-weight: 500; color: var(--pp-text-secondary);
}

/* ---- .pp-term — Hover definitions ---- */
.pp-term {
    font-weight: 700; color: var(--pp-text);
    text-decoration: underline; text-decoration-style: dotted;
    text-decoration-color: var(--pp-purple-accent);
    text-underline-offset: 3px;
    cursor: help; position: relative;
}
.pp-term:hover .pp-tooltip,
.pp-term:focus .pp-tooltip { display: block; }
.pp-tooltip {
    display: none; position: absolute;
    bottom: calc(100% + 8px); left: 50%;
    transform: translateX(-50%);
    background: #1E1B4B; color: #E2E8F0;
    padding: 12px 16px; border-radius: 12px;
    font-size: 12px; font-weight: 600; line-height: 1.5;
    width: max-content; max-width: 300px; z-index: 50;
    box-shadow: 0 4px 12px rgba(0,0,0,0.25);
    pointer-events: none;
}
.pp-tooltip::after {
    content: ''; position: absolute;
    top: 100%; left: 50%; transform: translateX(-50%);
    border: 6px solid transparent;
    border-top-color: #1E1B4B;
}
/* Kill nested tooltips — terms inside tooltip text should be plain */
.pp-tooltip .pp-term {
    font-weight: inherit; text-decoration: none;
    cursor: inherit; position: static; color: inherit;
}
.pp-tooltip .pp-tooltip { display: none !important; }
/* No glossary term styling in headings, subtitles, breadcrumbs, nav */
h1 .pp-term, h2 .pp-term, h3 .pp-term,
.pp-header-subtitle .pp-term,
.pp-breadcrumb .pp-term,
.pp-note-nav .pp-term {
    font-weight: inherit; text-decoration: none;
    cursor: default; position: static; color: inherit;
}
h1 .pp-tooltip, h2 .pp-tooltip, h3 .pp-tooltip,
.pp-header-subtitle .pp-tooltip,
.pp-breadcrumb .pp-tooltip,
.pp-note-nav .pp-tooltip { display: none !important; }

/* ---- .pp-examiner-card — Accept/Reject/Condone ---- */
.pp-examiner-cards { display: flex; flex-direction: column; gap: 8px; margin: 12px 0; }
.pp-examiner-card {
    display: flex; align-items: flex-start; gap: 10px;
    padding: 12px 16px; border-radius: 10px;
    border: 1px solid var(--pp-border);
    background: var(--pp-surface);
}
.pp-examiner-card-badge {
    flex-shrink: 0; padding: 3px 8px; border-radius: 6px;
    font-size: 10px; font-weight: 800; text-transform: uppercase;
    letter-spacing: 0.05em;
}
.pp-badge-accept { background: rgba(5,150,105,0.12); color: var(--pp-green); }
.pp-badge-reject { background: rgba(220,38,38,0.12); color: var(--pp-red); }
.pp-badge-condone { background: rgba(180,83,9,0.12); color: var(--pp-amber); }
.pp-examiner-card-text {
    font-size: 13px; font-weight: 500;
    color: var(--pp-text-secondary); line-height: 1.5;
}

/* ---- .pp-worked-example ---- */
.pp-worked-example {
    background: var(--pp-surface); border: 1px solid var(--pp-border);
    border-radius: 10px; margin: 12px 0; overflow: hidden;
}
.pp-worked-example summary {
    padding: 12px 16px; font-size: 13px; font-weight: 700;
    color: var(--pp-purple);
}
.pp-worked-example .pp-we-content { padding: 0 16px 16px; }
.pp-worked-example .pp-we-question {
    font-size: 13px; font-weight: 600; color: var(--pp-text);
    margin-bottom: 12px; padding: 10px 14px;
    background: var(--pp-purple-glow); border-radius: 8px;
}
.pp-worked-example .pp-we-step {
    display: flex; gap: 10px; margin-bottom: 8px;
}
.pp-worked-example .pp-we-step-num {
    width: 22px; height: 22px; border-radius: 6px;
    background: var(--pp-purple-glow); color: var(--pp-purple);
    display: flex; align-items: center; justify-content: center;
    font-size: 10px; font-weight: 800; flex-shrink: 0;
}
.pp-worked-example .pp-we-step-text {
    font-size: 13px; font-weight: 500; color: var(--pp-text-secondary);
}

/* ---- .pp-retrieval ---- */
.pp-retrieval-card {
    background: var(--pp-surface); border: 1px solid var(--pp-border);
    border-radius: 14px; padding: 16px 20px;
    margin-bottom: 10px; transition: border-color 0.25s;
}
.pp-retrieval-card:hover { border-color: rgba(124, 58, 237, 0.25); }
.pp-retrieval-q {
    display: flex; align-items: flex-start; gap: 10px;
}
.pp-retrieval-num {
    display: inline-flex; align-items: center; justify-content: center;
    width: 24px; height: 24px; border-radius: 6px;
    background: var(--pp-purple-glow); color: var(--pp-purple);
    font-size: 11px; font-weight: 800; flex-shrink: 0;
}
.pp-retrieval-text {
    font-size: 13px; font-weight: 600; color: var(--pp-text);
}
.pp-retrieval-answer {
    margin-top: 8px; padding: 12px 14px;
    background: var(--pp-teal-light);
    border: 1px solid rgba(13, 148, 136, 0.12);
    border-radius: 8px; display: none;
    font-size: 13px; font-weight: 500; color: var(--pp-text-secondary);
}
.pp-retrieval-answer.shown { display: block; }
.pp-reveal-btn {
    margin-top: 8px; padding: 4px 12px;
    border-radius: 6px; font-size: 11px; font-weight: 700;
    background: var(--pp-purple-glow); color: var(--pp-purple);
    border: 1px solid rgba(124, 58, 237, 0.15);
    cursor: pointer; transition: all 0.2s;
}
.pp-reveal-btn:hover { background: rgba(124, 58, 237, 0.15); }

/* ---- .pp-formula-ref ---- */
.pp-formula-ref {
    background: var(--pp-surface); border: 1px solid var(--pp-border);
    border-radius: 14px; padding: 24px 28px;
    scroll-margin-top: 72px;
}
.pp-formula-grid {
    display: grid; grid-template-columns: 1fr 1fr; gap: 12px 16px;
    align-items: start;
}
@media (max-width: 700px) {
    .pp-formula-grid { grid-template-columns: 1fr; }
}
.pp-formula-empty { min-height: 0; }
.pp-formula-column-header {
    display: flex; align-items: center; gap: 8px;
    font-size: 11px; font-weight: 800; text-transform: uppercase;
    letter-spacing: 0.06em; padding: 8px 12px; border-radius: 8px;
    margin-bottom: 8px;
}
.pp-formula-col-sheet {
    background: rgba(5,150,105,0.08); color: var(--pp-green);
}
.pp-formula-col-derive {
    background: rgba(180,83,9,0.08); color: var(--pp-amber);
}
.pp-formula-header {
    display: flex; align-items: center; gap: 10px; margin-bottom: 12px;
}
.pp-formula-label {
    font-size: 14px; font-weight: 800; color: var(--pp-text);
}
.pp-formula-pill {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 2px 8px; border-radius: 4px;
    font-size: 9px; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.04em;
}
.pp-pill-given { background: rgba(5,150,105,0.12); color: var(--pp-green); }
.pp-pill-derive { background: rgba(180,83,9,0.12); color: var(--pp-amber); }
.pp-pill-memorise { background: rgba(220,38,38,0.12); color: var(--pp-red); }
.pp-formula-math {
    text-align: center; padding: 16px 0;
    font-size: 18px;
}
/* ---- WHERE block — bullet list style ---- */
.pp-where-list {
    list-style: '■  '; margin: 8px 0 0 0; padding-left: 16px;
    font-size: 13px; line-height: 1.8; color: var(--pp-text-secondary);
}
.pp-where-list > li { margin-bottom: 2px; font-weight: 500; }
.pp-where-list > li::marker { color: var(--pp-text-muted); font-size: 10px; }
.pp-where-vars {
    list-style: '■  '; margin: 4px 0 0 0; padding-left: 18px;
    font-weight: 400;
}
.pp-where-vars li { margin-bottom: 3px; line-height: 1.6; }
.pp-where-vars li::marker { color: var(--pp-text-muted); font-size: 8px; }
.pp-formula-notes {
    margin-top: 8px; padding-left: 16px;
    font-size: 12px; font-weight: 500; font-style: italic;
    color: var(--pp-text-muted); line-height: 1.5;
}

/* ---- .pp-backlinks ---- */
.pp-backlinks { margin-top: 16px; display: flex; flex-wrap: wrap; gap: 6px; }
.pp-backlink {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 3px 10px; border-radius: 6px;
    font-size: 11px; font-weight: 600;
    background: var(--pp-purple-glow); color: var(--pp-purple);
    border: 1px solid rgba(124, 58, 237, 0.15);
    cursor: pointer; transition: all 0.2s; text-decoration: none;
}
.pp-backlink:hover {
    background: rgba(124, 58, 237, 0.14);
    border-color: rgba(124, 58, 237, 0.3);
    text-decoration: none;
}
.pp-backlink-prereq { color: var(--pp-amber); background: var(--pp-amber-light); border-color: rgba(180,83,9,0.15); }
.pp-backlink-extension { color: var(--pp-teal); background: var(--pp-teal-light); border-color: rgba(13,148,136,0.15); }
.pp-backlink-application { color: var(--pp-purple); }

/* ---- .pp-diagram-placeholder ---- */
.pp-diagram-placeholder {
    background: var(--pp-purple-glow); border: 2px dashed var(--pp-border);
    border-radius: 16px; padding: 32px; margin: 12px 0;
    text-align: center; min-height: 120px;
    display: flex; flex-direction: column; align-items: center;
    justify-content: center; gap: 8px;
}
.pp-diagram-placeholder .pp-dp-icon { font-size: 24px; opacity: 0.5; }
.pp-diagram-placeholder .pp-dp-caption {
    font-size: 12px; font-weight: 600; color: var(--pp-text-muted);
}

/* ---- .pp-sim-placeholder ---- */
.pp-sim-placeholder {
    border: 2px dashed var(--pp-purple);
    border-radius: 12px; padding: 20px; margin: 12px 0;
    display: flex; align-items: center; gap: 12px;
    background: var(--pp-purple-glow);
}
.pp-sim-badge {
    display: inline-flex; align-items: center; justify-content: center;
    width: 32px; height: 18px; border-radius: 4px;
    background: linear-gradient(135deg, var(--pp-purple), var(--pp-teal));
    color: white; font-size: 8px; font-weight: 800; letter-spacing: 0.5px;
}
.pp-sim-title { font-size: 13px; font-weight: 700; color: var(--pp-text); }

/* ---- .pp-question-links ---- */
.pp-question-links { display: grid; grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); gap: 8px; margin: 12px 0; }
.pp-question-link {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 14px; border-radius: 10px;
    border: 1px solid var(--pp-border);
    background: var(--pp-surface);
    text-decoration: none; transition: all 0.2s;
}
.pp-question-link:hover { border-color: var(--pp-purple); text-decoration: none; }
.pp-ql-source {
    font-size: 9px; font-weight: 800; text-transform: uppercase;
    padding: 2px 6px; border-radius: 4px;
    letter-spacing: 0.05em;
}
.pp-ql-source-isaac { background: rgba(124,92,191,0.12); color: var(--pp-purple); }
.pp-ql-source-pmt { background: rgba(13,148,136,0.12); color: var(--pp-teal); }
.pp-ql-source-pp { background: rgba(180,83,9,0.12); color: var(--pp-amber); }
.pp-ql-title { font-size: 12px; font-weight: 600; color: var(--pp-text); }

/* ---- Tables ---- */
.pp-table { width: 100%; border-collapse: collapse; font-size: 13px; margin: 12px 0; }
.pp-table th, .pp-table td {
    border: 1px solid var(--pp-border); padding: 8px 12px; text-align: left;
}
.pp-table th {
    background: var(--pp-purple-glow); color: var(--pp-purple);
    font-weight: 700; font-size: 11px; text-transform: uppercase;
    letter-spacing: 0.04em;
}
.pp-table td { color: var(--pp-text-secondary); }
.pp-table td strong { color: var(--pp-text); }
.pp-table tr:nth-child(even) { background: var(--pp-purple-glow); }

/* ---- .pp-toc-sidebar ---- */
.pp-toc {
    position: sticky; top: 72px;
    max-height: calc(100vh - 90px);
    overflow-y: auto;
}
.pp-toc-title {
    font-size: 10px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em;
    color: var(--pp-text-muted); margin-bottom: 12px;
}
.pp-toc-item {
    display: flex; align-items: center; gap: 8px;
    padding: 7px 12px; border-radius: 8px;
    font-size: 12px; font-weight: 500;
    color: var(--pp-text-muted); cursor: pointer;
    transition: all 0.2s; text-decoration: none;
    border-left: 2px solid transparent;
}
.pp-toc-item:hover { color: var(--pp-text); background: var(--pp-purple-glow); text-decoration: none; }
.pp-toc-item.active {
    color: var(--pp-purple); background: var(--pp-purple-glow);
    border-left-color: var(--pp-purple); font-weight: 700;
}
.pp-toc-num {
    width: 20px; height: 20px; border-radius: 5px;
    font-size: 9px; font-weight: 800;
    display: inline-flex; align-items: center; justify-content: center;
    background: var(--pp-border); color: var(--pp-text-muted);
    flex-shrink: 0; transition: all 0.2s;
}
.pp-toc-item.active .pp-toc-num {
    background: var(--pp-purple); color: #fff;
}

/* ---- Board badge ---- */
.pp-board-badge {
    display: inline-flex; padding: 2px 8px; border-radius: 4px;
    font-size: 10px; font-weight: 800; text-transform: uppercase;
    letter-spacing: 0.05em;
}
.pp-board-aqa { background: rgba(124,92,191,0.12); color: var(--pp-purple); }
.pp-board-ocr { background: rgba(13,148,136,0.12); color: var(--pp-teal); }

/* ---- Section titles ---- */
.pp-section-title {
    font-size: 11px; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.1em;
    color: var(--pp-purple); margin-bottom: 16px;
    display: flex; align-items: center; gap: 8px;
}
.pp-section-title::after {
    content: ''; flex: 1; height: 1px;
    background: var(--pp-border);
}

/* ---- SME-Style Definition Card ---- */
.pp-definition-card {
    background: var(--pp-purple-light);
    border: 1px solid rgba(124, 58, 237, 0.15);
    border-left: 4px solid var(--pp-purple);
    border-radius: 0 12px 12px 0;
    padding: 0; margin: 16px 0; overflow: hidden;
}
.pp-definition-header {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 16px;
    background: rgba(124, 58, 237, 0.08);
    font-size: 13px; font-weight: 800;
    color: var(--pp-purple);
    text-transform: uppercase; letter-spacing: 0.04em;
}
.pp-definition-header svg { color: var(--pp-purple); flex-shrink: 0; }
.pp-definition-body {
    padding: 12px 16px 14px;
    font-size: 14px; font-weight: 500; line-height: 1.7;
    color: var(--pp-text-secondary);
}
.pp-definition-body strong { color: var(--pp-text); font-weight: 700; }

/* ---- SME-Style Examiner Tip Card ---- */
.pp-tip-card {
    background: #EEF2FF;
    border: 1px solid rgba(99, 102, 241, 0.15);
    border-left: 4px solid #6366F1;
    border-radius: 0 12px 12px 0;
    padding: 0; margin: 16px 0; overflow: hidden;
}
[data-theme="dark"] .pp-tip-card {
    background: rgba(99, 102, 241, 0.08);
    border-color: rgba(99, 102, 241, 0.2);
    border-left-color: #818CF8;
}
.pp-tip-header {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 16px;
    background: rgba(99, 102, 241, 0.06);
    font-size: 13px; font-weight: 800;
    color: #4F46E5;
    text-transform: uppercase; letter-spacing: 0.04em;
}
[data-theme="dark"] .pp-tip-header { color: #A5B4FC; }
.pp-tip-header svg { color: #6366F1; flex-shrink: 0; }
[data-theme="dark"] .pp-tip-header svg { color: #818CF8; }
.pp-tip-body {
    padding: 12px 16px 14px;
    font-size: 14px; font-weight: 500; line-height: 1.7;
    color: #312E81;
}
[data-theme="dark"] .pp-tip-body { color: #C7D2FE; }

/* ---- SME-Style Common Mistake Card ---- */
.pp-mistake-card {
    background: #FEF2F2;
    border: 1px solid rgba(239, 68, 68, 0.12);
    border-left: 4px solid #EF4444;
    border-radius: 0 12px 12px 0;
    padding: 0; margin: 16px 0; overflow: hidden;
}
[data-theme="dark"] .pp-mistake-card {
    background: rgba(239, 68, 68, 0.06);
    border-color: rgba(239, 68, 68, 0.15);
    border-left-color: #F87171;
}
.pp-mistake-header {
    display: flex; align-items: center; gap: 8px;
    padding: 10px 16px;
    background: rgba(239, 68, 68, 0.05);
    font-size: 13px; font-weight: 800;
    color: #DC2626;
    text-transform: uppercase; letter-spacing: 0.04em;
}
[data-theme="dark"] .pp-mistake-header { color: #FCA5A5; }
.pp-mistake-header svg { color: #EF4444; flex-shrink: 0; }
[data-theme="dark"] .pp-mistake-header svg { color: #F87171; }
.pp-mistake-body {
    padding: 12px 16px 14px;
    font-size: 14px; font-weight: 500; line-height: 1.7;
    color: #7F1D1D;
}
[data-theme="dark"] .pp-mistake-body { color: #FECACA; }
.pp-mistake-body strong { color: #991B1B; font-weight: 700; }
[data-theme="dark"] .pp-mistake-body strong { color: #FCA5A5; }

/* ---- SME-Style Worked Example Card ---- */
.pp-we-card {
    background: #F9FAFB;
    border: 1px solid #E5E7EB;
    border-radius: 12px;
    padding: 0; margin: 16px 0; overflow: hidden;
}
[data-theme="dark"] .pp-we-card {
    background: rgba(255, 255, 255, 0.03);
    border-color: var(--pp-border);
}
.pp-we-header {
    display: flex; align-items: center; gap: 8px;
    padding: 12px 16px;
    background: rgba(5, 150, 105, 0.06);
    border-bottom: 1px solid #E5E7EB;
    font-size: 15px; font-weight: 800;
    color: #059669;
}
[data-theme="dark"] .pp-we-header {
    background: rgba(52, 211, 153, 0.06);
    border-bottom-color: var(--pp-border);
    color: #34D399;
}
.pp-we-header svg { color: #059669; flex-shrink: 0; }
[data-theme="dark"] .pp-we-header svg { color: #34D399; }
.pp-we-marks-total {
    font-size: 12px; font-weight: 700;
    color: var(--pp-purple); margin-left: 4px;
}
.pp-we-question {
    padding: 14px 16px;
    font-size: 14px; font-weight: 500; line-height: 1.7;
    color: var(--pp-text);
}
.pp-we-reveal {
    display: block; padding: 10px 16px;
    font-size: 13px; font-weight: 700;
    color: #059669; cursor: pointer;
    border-top: 1px solid #E5E7EB;
}
[data-theme="dark"] .pp-we-reveal {
    color: #34D399;
    border-top-color: var(--pp-border);
}
.pp-we-reveal:hover { text-decoration: underline; }
.pp-we-steps { padding: 0 24px 16px; }
.pp-we-step {
    display: flex; gap: 12px;
    align-items: flex-start;
    margin: 0; padding: 24px 0;
    border-bottom: 1px solid var(--pp-border-subtle);
}
.pp-we-step:last-child { border-bottom: none; }
.pp-we-step-num {
    width: 28px; height: 28px; border-radius: 50%;
    background: #059669; color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 12px; font-weight: 700; flex-shrink: 0;
    margin-top: 0;
}
[data-theme="dark"] .pp-we-step-num { background: #34D399; color: #064E3B; }
.pp-we-step-text {
    font-size: 15px; font-weight: 400; line-height: 1.8;
    color: var(--pp-text); min-width: 0; flex: 1;
}
.pp-we-step-text p {
    margin: 0 0 4px 0;
}
.pp-we-step-text .MathJax_Display,
.pp-we-step-text .MathJax[display="true"],
.pp-we-step-text mjx-container[display="true"] {
    margin: 16px 0 !important; text-align: center;
}
/* Bullet points inside worked example steps */
.pp-we-bullets {
    list-style: none; padding-left: 0; margin: 8px 0;
}
.pp-we-bullets li {
    position: relative; padding-left: 24px; margin-bottom: 8px;
    line-height: 1.8;
}
.pp-we-bullets li::before {
    content: ''; position: absolute; left: 4px; top: 10px;
    width: 6px; height: 6px; border-radius: 50%;
    background: #059669;
}
.pp-we-marks {
    font-size: 11px; font-weight: 700;
    color: var(--pp-purple);
}
/* Answer box */
.pp-we-answer {
    background: rgba(5, 150, 105, 0.04); border: 2px solid rgba(5, 150, 105, 0.2);
    border-radius: 8px; padding: 16px 20px; margin: 24px 24px 16px;
}
.pp-we-answer-label {
    font-size: 12px; font-weight: 700; text-transform: uppercase;
    letter-spacing: 0.5px; color: #059669; margin-bottom: 4px;
}
.pp-we-answer-value {
    font-size: 17px; font-weight: 600; color: var(--pp-text);
}
[data-theme="dark"] .pp-we-answer {
    background: rgba(52, 211, 153, 0.08); border-color: rgba(52, 211, 153, 0.25);
}

/* ---- Worked Example Instruction Label ---- */
.pp-we-instruction {
    font-size: 13px; font-weight: 600;
    color: #059669; margin-bottom: 6px;
}
[data-theme="dark"] .pp-we-instruction { color: #34D399; }

/* ---- Definition Card — equation ---- */
.pp-def-equation {
    margin-top: 10px; text-align: center; padding: 12px 0;
    font-size: 18px;
}
/* Definition cards reuse .pp-where-list / .pp-where-vars for variable defs */

/* ---- Subsection toggles ---- */
.pp-subsection {
    margin: 16px 0;
    padding: 12px 16px;
    border-left: 3px solid var(--pp-teal);
    background: var(--pp-teal-light);
    border-radius: 0 10px 10px 0;
}
.pp-subsection + .pp-subsection {
    margin-top: 12px;
}
.pp-subsection > summary {
    cursor: pointer;
    list-style: none;
    display: flex;
    align-items: center;
    gap: 8px;
}
.pp-subsection > summary::-webkit-details-marker { display: none; }
.pp-subsection > summary::before {
    content: '\25B6';
    display: inline-block;
    font-size: 0.6em;
    color: var(--pp-teal);
    transition: transform 0.2s;
}
.pp-subsection[open] > summary::before {
    transform: rotate(90deg);
}

/* ---- Formula Item — self-contained card ---- */
.pp-formula-item {
    padding: 14px 16px;
    border: 1px solid var(--pp-border-subtle);
    border-radius: 10px;
    background: var(--pp-surface);
    margin-bottom: 0;
}
.pp-formula-item .pp-formula-math,
.pp-formula-item .pp-where-list,
.pp-formula-item .pp-formula-notes {
    padding-left: 4px; padding-right: 4px;
}
.pp-formula-item > summary {
    display: flex; align-items: center; gap: 10px;
    cursor: pointer; list-style: none;
}
.pp-formula-item > summary::-webkit-details-marker { display: none; }
.pp-formula-item > summary::before {
    content: '\25B6'; display: inline-block; width: 1.2em;
    font-size: 0.7em; color: var(--pp-purple);
    transition: transform 0.2s; vertical-align: middle;
}
.pp-formula-item[open] > summary::before { transform: rotate(90deg); }

/* ---- Left Topic Sidebar ---- */
.pp-topic-nav {
    width: 240px; flex-shrink: 0;
    position: sticky; top: 72px;
    max-height: calc(100vh - 90px);
    overflow-y: auto;
    padding: 12px;
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px;
    scrollbar-width: thin;
    scrollbar-color: var(--pp-border) transparent;
}
.pp-topic-nav::-webkit-scrollbar { width: 4px; }
.pp-topic-nav::-webkit-scrollbar-thumb { background: var(--pp-border); border-radius: 4px; }
.pp-topic-nav-home {
    display: flex; align-items: center; gap: 8px;
    padding: 8px 10px; margin-bottom: 8px;
    font-size: 12px; font-weight: 700; color: var(--pp-purple);
    text-decoration: none; border-radius: 8px;
    border-bottom: 1px solid var(--pp-border);
    padding-bottom: 10px;
    transition: background 0.15s;
}
.pp-topic-nav-home:hover { background: var(--pp-purple-glow); text-decoration: none; }
.pp-topic-nav-collapse {
    position: absolute; top: 8px; right: 8px;
    width: 24px; height: 24px; border-radius: 6px;
    border: 1px solid var(--pp-border); background: var(--pp-surface);
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    font-size: 10px; color: var(--pp-text-muted); transition: all 0.15s;
}
.pp-topic-nav-collapse:hover { border-color: var(--pp-purple); color: var(--pp-purple); }
.pp-topic-nav.collapsed {
    width: 44px; padding: 8px;
    overflow: hidden;
}
.pp-topic-nav.collapsed .pp-topic-nav-home span,
.pp-topic-nav.collapsed .pp-topic-nav-section,
.pp-topic-nav.collapsed .pp-topic-nav-home { font-size: 0; gap: 0; border: none; margin: 0; padding: 8px; justify-content: center; }
.pp-topic-nav.collapsed .pp-topic-nav-home svg { width: 18px; height: 18px; }
.pp-topic-nav.collapsed .pp-topic-nav-section { display: none; }
.pp-topic-nav.collapsed .pp-topic-nav-collapse { position: static; margin: 4px auto 0; }
.pp-topic-nav-section {
    margin-bottom: 4px; border: none;
}
.pp-topic-nav-section > summary {
    list-style: none; cursor: pointer;
}
.pp-topic-nav-section > summary::-webkit-details-marker { display: none; }
.pp-topic-nav-section-title {
    font-size: 10px; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.1em;
    color: var(--pp-text-muted); padding: 8px 8px 4px;
    display: flex; align-items: center; gap: 6px;
}
.pp-topic-nav-section-title::before {
    content: ''; width: 6px; height: 6px; border-radius: 2px;
    background: var(--pp-purple); flex-shrink: 0;
}
.pp-topic-nav-section-title::after {
    content: '▸'; margin-left: auto; font-size: 9px;
    color: var(--pp-text-muted); transition: transform 0.2s;
}
.pp-topic-nav-section[open] > summary .pp-topic-nav-section-title::after {
    transform: rotate(90deg);
}
.pp-topic-nav-section-links {
    padding: 2px 0 4px;
}
.pp-topic-nav-link {
    display: flex; align-items: center; gap: 8px;
    padding: 5px 10px 5px 20px;
    font-size: 12px; font-weight: 500;
    color: var(--pp-text-muted);
    text-decoration: none; border-radius: 6px;
    border-left: 2px solid transparent;
    transition: all 0.15s; line-height: 1.3;
}
.pp-topic-nav-link:hover {
    color: var(--pp-text); background: var(--pp-purple-glow);
    text-decoration: none;
}
.pp-topic-nav-link.current {
    color: var(--pp-purple); background: var(--pp-purple-glow);
    border-left-color: var(--pp-purple); font-weight: 700;
}
.pp-topic-nav-num {
    font-size: 9px; font-weight: 700; color: var(--pp-text-muted);
    min-width: 18px;
}
.pp-topic-nav-link.current .pp-topic-nav-num { color: var(--pp-purple); }

/* Atomic pages inside layout wrapper — flex child instead of centered block */
.pp-layout .pp-atomic-main {
    flex: 1; min-width: 0; max-width: 780px;
    margin: 0; /* override margin: 0 auto from inline style */
}

@media (max-width: 1280px) {
    .pp-topic-nav { display: none; }
}

/* ---- Right TOC Sidebar Card ---- */
.pp-toc-card {
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px;
    padding: 14px;
}
.pp-toc-card > summary {
    list-style: none; cursor: pointer;
    font-size: 10px; font-weight: 800;
    text-transform: uppercase; letter-spacing: 0.12em;
    color: var(--pp-text-muted);
    display: flex; align-items: center; gap: 4px;
}
.pp-toc-card > summary::-webkit-details-marker { display: none; }
.pp-toc-card > summary::after {
    content: '▸'; margin-left: auto; font-size: 9px;
    color: var(--pp-text-muted); transition: transform 0.2s;
}
.pp-toc-card[open] > summary::after {
    transform: rotate(90deg);
}
.pp-toc-card #toc-links { margin-top: 8px; }

/* ---- Back to Top Button ---- */
.pp-back-to-top-col {
    width: 0; flex-shrink: 0; position: relative;
}
.pp-back-to-top {
    position: sticky; top: calc(100vh - 68px); z-index: 90;
    width: 36px; height: 36px; border-radius: 10px;
    margin-left: -18px;
    background: var(--pp-surface); border: 1px solid var(--pp-border);
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    opacity: 0; pointer-events: none;
    transition: opacity 0.25s, transform 0.25s, border-color 0.2s;
    transform: translateY(8px);
}
.pp-back-to-top.visible {
    opacity: 1; pointer-events: auto; transform: translateY(0);
}
.pp-back-to-top:hover {
    border-color: var(--pp-purple);
    box-shadow: 0 4px 16px rgba(124, 58, 237, 0.15);
}
.pp-back-to-top svg {
    width: 16px; height: 16px; color: var(--pp-text-muted);
    transition: color 0.2s;
}
.pp-back-to-top:hover svg { color: var(--pp-purple); }

/* ---- Site Title in Nav ---- */
.pp-site-title {
    font-size: 14px; font-weight: 800; color: var(--pp-purple);
    letter-spacing: -0.01em; white-space: nowrap;
}

/* ---- Utility ---- */
.pp-hidden { display: none !important; }
.pp-sr-only {
    position: absolute; width: 1px; height: 1px;
    padding: 0; margin: -1px; overflow: hidden;
    clip: rect(0, 0, 0, 0); border: 0;
}

/* ================================================================
   ATOMIC PAGE SYSTEM — New classes for atomic sub-pages
   ================================================================ */

/* ---- .pp-note-card-atomic — Single note, no collapse ---- */
.pp-note-card-atomic {
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px;
    padding: 28px 32px;
    margin-bottom: 20px;
    transition: border-color 0.25s;
}
.pp-note-card-atomic:hover {
    border-color: rgba(124, 58, 237, 0.25);
    box-shadow: var(--pp-shadow-card);
}

/* ---- .pp-spec-tag — Prominent spec code badge ---- */
.pp-spec-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    border-radius: 8px;
    font-size: 11px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--pp-purple);
    background: var(--pp-purple-glow);
    border: 1px solid rgba(124, 58, 237, 0.15);
    margin-bottom: 12px;
}

/* ---- .pp-note-nav — Prev/Next navigation bar ---- */
.pp-note-nav {
    border-top: 1px solid var(--pp-border);
    background: var(--pp-surface);
    padding: 16px 24px;
    margin-top: 32px;
}
.pp-note-nav-inner {
    max-width: 780px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 12px;
    align-items: center;
}
.pp-note-nav-overview {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    font-weight: 700;
    color: var(--pp-purple);
    text-decoration: none;
}
.pp-note-nav-overview:hover { text-decoration: underline; }
.pp-note-nav-row {
    display: flex;
    align-items: center;
    gap: 16px;
    width: 100%;
    justify-content: center;
}
.pp-note-nav-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 10px;
    font-size: 13px;
    font-weight: 600;
    color: var(--pp-purple);
    background: var(--pp-purple-glow);
    border: 1px solid rgba(124, 58, 237, 0.15);
    text-decoration: none;
    transition: all 0.2s;
    max-width: 320px;
    text-align: center;
    line-height: 1.3;
}
.pp-note-nav-link:hover {
    background: rgba(124, 58, 237, 0.14);
    border-color: rgba(124, 58, 237, 0.3);
    text-decoration: none;
}
.pp-note-nav-link.disabled {
    opacity: 0.3;
    pointer-events: none;
}
.pp-note-nav-counter {
    font-size: 12px;
    font-weight: 700;
    color: var(--pp-text-muted);
    min-width: 60px;
    text-align: center;
}

@media (max-width: 600px) {
    .pp-note-nav-row { gap: 8px; }
    .pp-note-nav-link { padding: 6px 10px; font-size: 12px; max-width: 200px; }
}

/* ---- .pp-factsheet-grid — Overview page note list ---- */
.pp-factsheet-grid {
    margin-bottom: 24px;
}
.pp-factsheet-row {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: 10px;
    border: 1px solid var(--pp-border);
    background: var(--pp-surface);
    margin-bottom: 8px;
    text-decoration: none;
    transition: all 0.2s;
}
.pp-factsheet-row:hover {
    border-color: rgba(124, 58, 237, 0.3);
    box-shadow: var(--pp-shadow-card);
    text-decoration: none;
}
.pp-factsheet-row .pp-note-badge {
    width: 28px;
    height: 28px;
    font-size: 11px;
}
.pp-factsheet-title {
    font-size: 14px;
    font-weight: 700;
    color: var(--pp-text);
    flex: 1;
    min-width: 0;
}
.pp-factsheet-preview {
    font-size: 12px;
    font-weight: 500;
    color: var(--pp-text-muted);
    max-width: 280px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.pp-factsheet-arrow {
    color: var(--pp-purple);
    font-size: 16px;
    flex-shrink: 0;
}

@media (max-width: 700px) {
    .pp-factsheet-preview { display: none; }
}

/* ---- .pp-coach-card — Coach's Corner callout ---- */
.pp-coach-card {
    background: #FAF5FF;
    border: 1px solid rgba(139, 92, 246, 0.15);
    border-left: 4px solid #8B5CF6;
    border-radius: 0 12px 12px 0;
    padding: 0;
    margin: 20px 0;
    overflow: hidden;
}
[data-theme="dark"] .pp-coach-card {
    background: rgba(139, 92, 246, 0.08);
    border-color: rgba(139, 92, 246, 0.2);
    border-left-color: #A78BFA;
}
.pp-coach-header {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background: rgba(139, 92, 246, 0.06);
    font-size: 13px;
    font-weight: 800;
    color: #7C3AED;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}
[data-theme="dark"] .pp-coach-header { color: #C4B5FD; }
.pp-coach-header svg { color: #8B5CF6; flex-shrink: 0; }
[data-theme="dark"] .pp-coach-header svg { color: #A78BFA; }
.pp-coach-body {
    padding: 12px 16px 14px;
}
.pp-coach-body blockquote {
    font-size: 14px;
    font-weight: 500;
    line-height: 1.7;
    color: #4C1D95;
    font-style: italic;
    margin: 0 0 8px;
    padding: 0;
    border: none;
}
[data-theme="dark"] .pp-coach-body blockquote { color: #DDD6FE; }
.pp-coach-tag {
    display: inline-flex;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 9px;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: rgba(139, 92, 246, 0.12);
    color: #7C3AED;
}
[data-theme="dark"] .pp-coach-tag {
    background: rgba(167, 139, 250, 0.15);
    color: #C4B5FD;
}

/* ================================================================
   PRACTICE QUESTIONS v3 — Restyled "Notion-meets-SaaS"
   ================================================================ */
.pp-pv2 {
    margin: 2.5rem 0;
}

/* ---- Callout container ---- */
.pv2-callout {
    background: var(--pp-purple-light);
    border: 1px solid rgba(124, 58, 237, 0.10);
    border-radius: 16px;
    padding: 1.5rem 1.75rem 0.5rem;
    margin-bottom: 1.5rem;
    box-shadow: var(--pp-shadow-card);
}
.pv2-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 1rem;
}
.pv2-title {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--pp-purple);
    margin: 0;
    letter-spacing: -0.01em;
}
.pv2-refresh {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.3rem 0.65rem;
    border: 1px solid var(--pp-border);
    border-radius: 8px;
    background: var(--pp-surface);
    color: var(--pp-purple);
    cursor: pointer;
    transition: all 0.15s;
}
.pv2-refresh:hover {
    border-color: var(--pp-purple);
}
.pv2-progress-summary {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--pp-text-muted);
    letter-spacing: 0.02em;
    background: var(--pp-surface);
    padding: 4px 12px;
    border-radius: 20px;
    border: 1px solid var(--pp-border);
}

/* ---- Difficulty tabs ---- */
.pv2-tabs { position: relative; }
.pv2-tab-bar {
    display: flex;
    gap: 0;
    border-bottom: 2px solid rgba(124, 58, 237, 0.08);
}
.pv2-tab {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.65rem 0.5rem;
    font-size: 0.82rem;
    font-weight: 700;
    border: none;
    background: transparent;
    color: var(--pp-text-muted);
    cursor: pointer;
    transition: color 0.2s;
    position: relative;
}
.pv2-tab:hover:not(.locked) { color: var(--pp-text); }
.pv2-tab.active { color: var(--pp-purple); }
.pv2-tab-easy.active   { color: var(--pp-green); }
.pv2-tab-medium.active { color: var(--pp-amber); }
.pv2-tab-hard.active   { color: var(--pp-red); }

/* Active tab underline via pseudo-element */
.pv2-tab.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 15%;
    right: 15%;
    height: 2px;
    border-radius: 1px;
    background: var(--pp-purple);
}
.pv2-tab-easy.active::after   { background: var(--pp-green); }
.pv2-tab-medium.active::after { background: var(--pp-amber); }
.pv2-tab-hard.active::after   { background: var(--pp-red); }

.pv2-tab-count {
    font-size: 0.6rem;
    font-weight: 700;
    padding: 0.15rem 0.45rem;
    border-radius: 6px;
    background: rgba(124, 58, 237, 0.06);
    color: var(--pp-text-muted);
}
.pv2-tab.active .pv2-tab-count {
    background: var(--pp-purple);
    color: #fff;
}
.pv2-tab-easy.active .pv2-tab-count   { background: var(--pp-green); color: #fff; }
.pv2-tab-medium.active .pv2-tab-count { background: var(--pp-amber); color: #fff; }
.pv2-tab-hard.active .pv2-tab-count   { background: var(--pp-red); color: #fff; }

/* ---- Tab indicator (legacy, kept for JS compat) ---- */
.pv2-tab-indicator {
    position: absolute;
    bottom: 0;
    height: 2px;
    background: var(--pp-purple);
    border-radius: 1px;
    transition: left 0.25s ease, width 0.25s ease;
}

/* ---- Locked tab ---- */
.pv2-tab.locked {
    opacity: 0.35;
    cursor: not-allowed;
}
.pv2-tab.locked:hover { color: var(--pp-text-muted); }
.pv2-lock-icon { font-size: 0.65rem; margin-right: 0.15rem; }
.pv2-unlock-hint {
    font-size: 0.52rem;
    font-weight: 500;
    color: var(--pp-text-muted);
    margin-left: 0.15rem;
    white-space: nowrap;
}

/* ---- Cards container ---- */
.pv2-cards {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

/* ---- Question card ---- */
.pv2-card {
    border: 1px solid var(--pp-border);
    border-left: 4px solid var(--pp-green);
    border-radius: 14px;
    padding: 1.5rem 1.75rem;
    background: var(--pp-surface);
    box-shadow: var(--pp-shadow-card);
    transition: box-shadow 0.25s ease, border-color 0.25s ease;
}
.pv2-card:hover {
    box-shadow: var(--pp-shadow-card-hover);
}
.pv2-card-correct { border-left-color: var(--pp-green) !important; }
.pv2-card-wrong { border-left-color: var(--pp-red) !important; }
.pv2-card-medium { border-left-color: var(--pp-amber); }
.pv2-card-hard   { border-left-color: var(--pp-red); }

/* ---- Card top bar ---- */
.pv2-card-top {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}
.pv2-q-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--pp-purple);
    color: #fff;
    font-weight: 800;
    font-size: 0.78rem;
    flex-shrink: 0;
}
.pv2-marks-label {
    font-size: 0.72rem;
    font-weight: 600;
    color: var(--pp-text-muted);
    background: var(--pp-code-bg);
    padding: 0.2rem 0.7rem;
    border-radius: 999px;
}
.pv2-answer-badge {
    font-size: 0.6rem;
    font-weight: 700;
    padding: 0.15rem 0.55rem;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}
.pv2-badge-correct {
    background: var(--pp-green-light);
    color: var(--pp-green);
    border: 1px solid rgba(5, 150, 105, 0.15);
}
.pv2-badge-wrong {
    background: var(--pp-red-light);
    color: var(--pp-red);
    border: 1px solid rgba(220, 38, 38, 0.12);
}
.pv2-collapse-btn {
    background: none; border: none; cursor: pointer;
    font-size: 0.65rem; color: var(--pp-text-muted);
    padding: 0.2rem 0.4rem; border-radius: 6px;
    transition: background 0.15s; margin-left: auto;
}
.pv2-collapse-btn:hover { background: var(--pp-code-bg); }

/* ---- Question stem ---- */
.pv2-stem {
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--pp-text);
    margin-bottom: 1.25rem;
}
.pv2-stem p, .pv2-stem ul, .pv2-stem ol, .pv2-stem table { white-space: normal; }
.pv2-stem p { margin: 0.5em 0; }
.pv2-stem img { max-width: 100%; height: auto; margin: 0.6em 0; border-radius: 8px; }
.pv2-stem table { border-collapse: collapse; margin: 0.6em 0; font-size: 0.85rem; }
.pv2-stem th, .pv2-stem td { border: 1px solid var(--pp-border); padding: 0.4em 0.7em; }
.pv2-stem th { background: var(--pp-purple-light); font-weight: 600; }

/* ---- Self-assessment (structured questions) ---- */
.pv2-self-assess {
    background: var(--pp-green-light);
    border: 1px solid rgba(5, 150, 105, 0.12);
    border-radius: 12px;
    padding: 1.1rem 1.25rem;
    margin-bottom: 1rem;
}
.pv2-self-label {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--pp-text);
    margin-bottom: 0.7rem;
}
.pv2-self-score { display: flex; align-items: center; gap: 1.1rem; }
.pv2-score-display { display: flex; align-items: baseline; gap: 0.15rem; }
.pv2-score-val {
    font-size: 1.6rem; font-weight: 800;
    color: var(--pp-green); min-width: 1.2em; text-align: center;
}
.pv2-score-val.pv2-score-empty { color: var(--pp-text-muted); opacity: 0.3; }
.pv2-score-sep { font-size: 1.1rem; font-weight: 600; color: var(--pp-text-muted); }
.pv2-score-max { font-size: 1.1rem; font-weight: 700; color: var(--pp-text-secondary); }
.pv2-score-btns { display: flex; gap: 0.4rem; flex-wrap: wrap; }
.pv2-score-btn {
    width: 36px; height: 36px; border-radius: 10px;
    border: 1.5px solid var(--pp-border);
    background: var(--pp-surface);
    color: var(--pp-text-secondary);
    font-weight: 700; font-size: 0.82rem;
    cursor: pointer; transition: all 0.15s;
    display: inline-flex; align-items: center; justify-content: center;
}
.pv2-score-btn:hover {
    border-color: var(--pp-green); color: var(--pp-green);
    background: rgba(5, 150, 105, 0.04);
}
.pv2-score-btn.selected {
    background: var(--pp-green); color: #fff; border-color: var(--pp-green);
}

/* ---- Action bar ---- */
.pv2-action-bar { margin-bottom: 0.5rem; }

/* ---- MCQ options ---- */
.pv2-mcq-picker {
    margin-top: 0.5rem;
    padding-top: 1rem;
    border-top: 1px solid var(--pp-border);
}
.pv2-mcq-label {
    font-size: 0.72rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.06em;
    color: var(--pp-text-muted); margin-bottom: 0.75rem;
}
.pv2-mcq-grid {
    display: flex; flex-direction: column;
    gap: 0.5rem; margin-bottom: 0.85rem;
}
.pv2-mcq-opt {
    display: flex; align-items: center;
    gap: 0.8rem; padding: 0.75rem 1rem;
    border: 2px solid var(--pp-border);
    border-radius: 12px;
    background: var(--pp-surface);
    cursor: pointer; transition: all 0.2s;
    text-align: left; width: 100%;
}
.pv2-mcq-opt:hover:not(.disabled):not(.selected) {
    border-color: var(--pp-purple);
    background: var(--pp-purple-light);
}
.pv2-mcq-opt:hover:not(.disabled):not(.selected) .pv2-mcq-letter {
    background: var(--pp-purple-light); color: var(--pp-purple);
    border-color: var(--pp-purple);
}
.pv2-mcq-opt.selected {
    border-color: var(--pp-purple);
    background: var(--pp-purple-light);
}
.pv2-mcq-opt.selected .pv2-mcq-letter {
    background: var(--pp-purple); color: #fff; border-color: var(--pp-purple);
}
.pv2-mcq-opt.correct {
    border-color: var(--pp-green);
    background: var(--pp-green-light);
}
.pv2-mcq-opt.correct .pv2-mcq-letter {
    background: var(--pp-green); color: #fff; border-color: var(--pp-green);
}
.pv2-mcq-opt.incorrect {
    border-color: var(--pp-red);
    background: var(--pp-red-light);
}
.pv2-mcq-opt.incorrect .pv2-mcq-letter {
    background: var(--pp-red); color: #fff; border-color: var(--pp-red);
}
.pv2-mcq-opt.disabled { cursor: default; opacity: 0.8; }
.pv2-mcq-letter {
    display: inline-flex; align-items: center; justify-content: center;
    width: 38px; height: 38px; min-width: 38px;
    border-radius: 10px;
    border: 2px solid var(--pp-border);
    background: var(--pp-bg);
    color: var(--pp-text);
    font-weight: 800; font-size: 0.85rem;
    flex-shrink: 0; transition: all 0.2s;
}
.pv2-mcq-text {
    font-size: 0.87rem; line-height: 1.6;
    color: var(--pp-text);
}
.pv2-mcq-text p { margin: 0; white-space: normal; }
.pv2-mcq-text img { max-width: 100%; height: auto; }
.pv2-mcq-actions {
    display: flex; align-items: center;
    gap: 0.8rem; margin-bottom: 0.6rem;
}
.pv2-mcq-result {
    padding: 0.55rem 1rem; border-radius: 10px;
    font-size: 0.85rem; font-weight: 700;
}
.pv2-mcq-result-correct {
    background: var(--pp-green-light);
    color: var(--pp-green);
    border: 1px solid rgba(5, 150, 105, 0.15);
}
.pv2-mcq-result-wrong {
    background: var(--pp-red-light);
    color: var(--pp-red);
    border: 1px solid rgba(220, 38, 38, 0.12);
}

/* ---- Submit button ---- */
.pv2-submit-btn {
    padding: 0.65rem 1.75rem;
    border: none; border-radius: 10px;
    background: var(--pp-purple);
    color: #fff; font-size: 0.85rem; font-weight: 700;
    cursor: pointer; transition: all 0.2s;
}
.pv2-submit-btn:hover { opacity: 0.88; }
.pv2-submit-btn.disabled {
    opacity: 0.35; cursor: not-allowed;
}

/* ---- View Answer button ---- */
.pv2-view-answer-btn {
    display: block; width: 100%;
    padding: 0.7rem;
    border: 1.5px solid var(--pp-purple);
    border-radius: 10px;
    background: transparent;
    color: var(--pp-purple);
    font-size: 0.85rem; font-weight: 700;
    cursor: pointer; transition: all 0.2s;
}
.pv2-view-answer-btn:hover {
    background: var(--pp-purple-light);
}

/* ---- Retry button ---- */
.pv2-retry-btn {
    display: inline-flex; align-items: center; gap: 0.3rem;
    font-size: 0.72rem; font-weight: 600;
    padding: 0.4rem 0.85rem; margin-top: 0.6rem;
    border: 1.5px solid var(--pp-border);
    border-radius: 8px;
    background: var(--pp-surface);
    color: var(--pp-text-secondary);
    cursor: pointer; transition: all 0.15s;
}
.pv2-retry-btn:hover {
    border-color: var(--pp-purple); color: var(--pp-purple);
    background: var(--pp-purple-light);
}

/* ---- Mark scheme list ---- */
.pv2-ms-list {
    list-style: none; padding: 0; margin: 0;
    display: flex; flex-direction: column; gap: 0.4rem;
}
.pv2-ms-list li {
    position: relative; padding-left: 1rem; line-height: 1.65;
}
.pv2-ms-list li::before {
    content: '\2022'; position: absolute; left: 0;
    color: var(--pp-purple); font-weight: 700;
}
.pv2-ms-mark {
    display: inline-block;
    padding: 0.12rem 0.5rem; margin-left: 0.3rem;
    background: var(--pp-purple-light); color: var(--pp-purple);
    font-size: 0.68rem; font-weight: 700;
    border-radius: 5px; vertical-align: middle;
}

/* ---- Feedback ---- */
.pv2-feedback {
    display: flex; align-items: center;
    gap: 0.55rem; padding: 0.65rem 1rem;
    border-radius: 10px; font-size: 0.85rem;
    font-weight: 700; margin-bottom: 1rem;
}
.pv2-fb-icon { font-size: 1rem; flex-shrink: 0; }
.pv2-fb-correct {
    background: var(--pp-green-light); color: var(--pp-green);
    border: 1px solid rgba(5, 150, 105, 0.15);
}
.pv2-fb-wrong {
    background: var(--pp-red-light); color: var(--pp-red);
    border: 1px solid rgba(220, 38, 38, 0.12);
}
.pv2-fb-partial {
    background: var(--pp-amber-light); color: var(--pp-amber);
    border: 1px solid rgba(217, 119, 6, 0.12);
}

/* ---- Toggle row (MS / WS / ER) ---- */
.pv2-toggle-row {
    display: flex; gap: 0;
    margin: 1rem 0 0;
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--pp-border);
}
.pv2-toggle-btn {
    flex: 1; padding: 0.6rem 0.5rem;
    font-size: 0.75rem; font-weight: 700;
    border: none;
    background: var(--pp-surface);
    color: var(--pp-text-muted);
    cursor: pointer; transition: all 0.2s;
    border-right: 1px solid var(--pp-border);
    text-transform: uppercase; letter-spacing: 0.04em;
}
.pv2-toggle-btn:last-child { border-right: none; }
.pv2-toggle-btn:hover { background: var(--pp-purple-light); color: var(--pp-text); }
.pv2-toggle-ms.active {
    background: var(--pp-purple); color: #fff;
}
.pv2-toggle-ws.active {
    background: var(--pp-amber); color: #fff;
}
.pv2-toggle-er.active {
    background: var(--pp-teal); color: #fff;
}

/* ---- Panels ---- */
.pv2-panel {
    margin-top: 0; padding: 1.1rem 1.25rem;
    font-size: 0.84rem; line-height: 1.65;
    border-radius: 0 0 10px 10px;
    border: 1px solid var(--pp-border);
    border-top: none;
}
.pv2-panel-ms {
    background: var(--pp-purple-light);
    border-color: rgba(124, 58, 237, 0.10);
}
.pv2-panel-ws {
    background: var(--pp-amber-light);
    border-color: rgba(217, 119, 6, 0.08);
}
.pv2-panel-er {
    background: var(--pp-teal-light);
    border-color: rgba(13, 148, 136, 0.08);
}
.pv2-panel-label {
    font-size: 0.65rem; font-weight: 700;
    text-transform: uppercase; letter-spacing: 0.08em;
    margin-bottom: 0.5rem;
}
.pv2-panel-ms .pv2-panel-label { color: var(--pp-purple); }
.pv2-panel-ws .pv2-panel-label { color: var(--pp-amber); }
.pv2-panel-er .pv2-panel-label { color: var(--pp-teal); }
.pv2-panel-content {
    color: var(--pp-text);
}
.pv2-panel-content p { margin: 0.5em 0; }
.pv2-panel-content ul, .pv2-panel-content ol { margin: 0.4em 0; padding-left: 1.4em; }
.pv2-panel-content li { margin-bottom: 0.25em; }
.pv2-panel-content table { border-collapse: collapse; margin: 0.6em 0; font-size: 0.82rem; }
.pv2-panel-content th, .pv2-panel-content td { border: 1px solid var(--pp-border); padding: 0.35em 0.65em; }
.pv2-panel-content th { background: var(--pp-purple-glow); font-weight: 600; }
.pv2-panel-content img { max-width: 100%; height: auto; margin: 0.5em 0; border-radius: 6px; }
.pv2-ws-placeholder {
    color: var(--pp-text-muted);
    font-style: italic;
}

/* ---- Locked message ---- */
.pv2-locked-msg {
    text-align: center; padding: 3rem 2rem;
    color: var(--pp-text-muted);
}
.pv2-locked-msg p { margin: 0.8rem 0 0; font-size: 0.88rem; line-height: 1.5; }
.pv2-lock-big { font-size: 2.5rem; display: block; opacity: 0.35; }

/* ---- Empty state ---- */
.pv2-empty {
    text-align: center; color: var(--pp-text-muted);
    font-size: 0.85rem; padding: 2.5rem;
}

/* ================================================================
   DARK THEME OVERRIDES — Practice Questions
   Rule: swap solid color fills for colored borders + text accents.
   Never use brand color as solid bg fill for large elements.
   ================================================================ */

/* -- Callout container -- */
[data-theme="dark"] .pv2-callout {
    background: rgba(255, 255, 255, 0.02);
    border-color: rgba(255, 255, 255, 0.06);
}
[data-theme="dark"] .pv2-title { color: #C4B5FD; }
[data-theme="dark"] .pv2-progress-summary {
    background: var(--pp-surface); border-color: var(--pp-border);
}
[data-theme="dark"] .pv2-refresh { background: var(--pp-surface); border-color: var(--pp-border); color: #C4B5FD; }

/* -- Difficulty tabs -- */
[data-theme="dark"] .pv2-tab-bar { border-color: rgba(255, 255, 255, 0.06); }
[data-theme="dark"] .pv2-tab.active { color: #C4B5FD; }
[data-theme="dark"] .pv2-tab-easy.active { color: #34D399; }
[data-theme="dark"] .pv2-tab-medium.active { color: #FBBF24; }
[data-theme="dark"] .pv2-tab-hard.active { color: #F87171; }
[data-theme="dark"] .pv2-tab.active::after { background: #A78BFA; }
[data-theme="dark"] .pv2-tab-easy.active::after { background: #34D399; }
[data-theme="dark"] .pv2-tab-medium.active::after { background: #FBBF24; }
[data-theme="dark"] .pv2-tab-hard.active::after { background: #F87171; }

/* -- Question cards -- */
[data-theme="dark"] .pv2-card {
    background: var(--pp-surface);
    border-color: var(--pp-border);
    border-left-color: var(--pp-green);
}
[data-theme="dark"] .pv2-card-correct { border-left-color: #34D399 !important; }
[data-theme="dark"] .pv2-card-wrong { border-left-color: #F87171 !important; }
[data-theme="dark"] .pv2-card-medium { border-left-color: #FBBF24; }
[data-theme="dark"] .pv2-card-hard { border-left-color: #F87171; }
[data-theme="dark"] .pv2-q-badge { background: var(--pp-surface-raised); border: 1.5px solid var(--pp-purple); color: var(--pp-purple); }
[data-theme="dark"] .pv2-marks-label { background: rgba(255, 255, 255, 0.04); }
[data-theme="dark"] .pv2-badge-correct { background: rgba(52, 211, 153, 0.08); color: #34D399; border-color: rgba(52, 211, 153, 0.12); }
[data-theme="dark"] .pv2-badge-wrong { background: rgba(248, 113, 113, 0.08); color: #F87171; border-color: rgba(248, 113, 113, 0.10); }

/* -- Self-assess -- */
[data-theme="dark"] .pv2-self-assess { background: rgba(52, 211, 153, 0.03); border-color: rgba(52, 211, 153, 0.08); }
[data-theme="dark"] .pv2-score-btn { background: var(--pp-surface); border-color: var(--pp-border); }

/* -- MCQ options: raised gray bg + colored border, NOT solid fill -- */
[data-theme="dark"] .pv2-mcq-opt { background: var(--pp-surface); border-color: var(--pp-border); }
[data-theme="dark"] .pv2-mcq-opt:hover:not(.disabled):not(.selected) {
    background: var(--pp-surface-raised); border-color: rgba(167, 139, 250, 0.3);
}
[data-theme="dark"] .pv2-mcq-letter {
    background: rgba(255, 255, 255, 0.04); color: var(--pp-text-secondary);
    border-color: var(--pp-border);
}
/* Selected: raised gray bg + purple border — NOT solid purple fill */
[data-theme="dark"] .pv2-mcq-opt.selected {
    background: var(--pp-surface-raised); border-color: var(--pp-purple);
}
[data-theme="dark"] .pv2-mcq-opt.selected .pv2-mcq-letter {
    background: transparent; color: var(--pp-purple);
    border-color: var(--pp-purple);
}
/* Correct: raised gray + green border */
[data-theme="dark"] .pv2-mcq-opt.correct {
    background: var(--pp-surface-raised); border-color: #34D399;
}
[data-theme="dark"] .pv2-mcq-opt.correct .pv2-mcq-letter {
    background: transparent; color: #34D399; border-color: #34D399;
}
/* Incorrect: raised gray + red border */
[data-theme="dark"] .pv2-mcq-opt.incorrect {
    background: var(--pp-surface-raised); border-color: #F87171;
}
[data-theme="dark"] .pv2-mcq-opt.incorrect .pv2-mcq-letter {
    background: transparent; color: #F87171; border-color: #F87171;
}

/* -- Submit / View Answer / Retry -- */
[data-theme="dark"] .pv2-submit-btn {
    background: transparent; border: 1.5px solid var(--pp-purple);
    color: var(--pp-purple);
}
[data-theme="dark"] .pv2-submit-btn:hover { background: rgba(167, 139, 250, 0.06); }
[data-theme="dark"] .pv2-submit-btn.disabled {
    background: transparent; border-color: var(--pp-border);
    color: var(--pp-text-muted);
}
[data-theme="dark"] .pv2-view-answer-btn { border-color: rgba(167, 139, 250, 0.3); color: #C4B5FD; }
[data-theme="dark"] .pv2-view-answer-btn:hover { background: rgba(167, 139, 250, 0.04); }
[data-theme="dark"] .pv2-retry-btn { background: var(--pp-surface); border-color: var(--pp-border); }
[data-theme="dark"] .pv2-retry-btn:hover { border-color: rgba(167, 139, 250, 0.3); color: #C4B5FD; background: rgba(167, 139, 250, 0.04); }

/* -- Toggle tabs: transparent bg + colored text + bottom accent — NOT solid fill -- */
[data-theme="dark"] .pv2-toggle-btn {
    background: var(--pp-surface); border-color: var(--pp-border);
    color: var(--pp-text-muted);
}
[data-theme="dark"] .pv2-toggle-btn:hover { background: var(--pp-surface-raised); color: var(--pp-text); }
[data-theme="dark"] .pv2-toggle-ms.active {
    background: transparent; color: #C4B5FD;
    box-shadow: inset 0 -2px 0 var(--pp-purple);
}
[data-theme="dark"] .pv2-toggle-ws.active {
    background: transparent; color: #FBBF24;
    box-shadow: inset 0 -2px 0 #FBBF24;
}
[data-theme="dark"] .pv2-toggle-er.active {
    background: transparent; color: #5EEAD4;
    box-shadow: inset 0 -2px 0 #5EEAD4;
}

/* -- Panels: clean surface gray — NOT muddy color tints -- */
[data-theme="dark"] .pv2-panel-ms {
    background: var(--pp-surface-raised);
    border-color: var(--pp-border);
    border-left: 2px solid var(--pp-purple);
}
[data-theme="dark"] .pv2-panel-ws {
    background: var(--pp-surface-raised);
    border-color: var(--pp-border);
    border-left: 2px solid #FBBF24;
}
[data-theme="dark"] .pv2-panel-er {
    background: var(--pp-surface-raised);
    border-color: var(--pp-border);
    border-left: 2px solid #5EEAD4;
}
[data-theme="dark"] .pv2-ms-mark { background: rgba(167, 139, 250, 0.08); color: #C4B5FD; }

/* -- Misc -- */
[data-theme="dark"] .pv2-collapse-btn:hover { background: rgba(255,255,255,0.04); }
[data-theme="dark"] .pv2-locked-msg { color: var(--pp-text-muted); }

/* ---- Mobile ---- */
@media (max-width: 700px) {
    .pv2-callout { padding: 1rem 1.1rem 0.3rem; border-radius: 12px; }
    .pv2-card { padding: 1.1rem; }
    .pv2-tab { font-size: 0.72rem; padding: 0.5rem 0.2rem; }
    .pv2-unlock-hint { display: none; }
    .pv2-toggle-btn { font-size: 0.7rem; padding: 0.5rem 0.3rem; }
    .pv2-self-assess { padding: 0.9rem; }
    .pv2-self-score { flex-direction: column; gap: 0.5rem; }
    .pv2-score-btn { width: 32px; height: 32px; font-size: 0.75rem; }
    .pv2-progress-summary { font-size: 0.62rem; }
}

/* ================================================================
   PRACTICE QUESTIONS — Retrieval Viewer (pp-practice-*)
   JS-generated viewer from pp-notes.js (SaveMyExams-style)
   ================================================================ */

/* ---- Header ---- */
.pp-practice-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 4px;
}
.pp-practice-header h2 {
    font-size: 1.15rem;
    font-weight: 800;
    color: var(--pp-text);
    margin: 0;
}

/* ---- Meta (question count) ---- */
.pp-practice-meta {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--pp-text-muted);
    margin-bottom: 16px;
}

/* ---- Pagination buttons ---- */
.pp-practice-pages {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    justify-content: center;
    margin-bottom: 20px;
}
.pp-practice-page-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 34px;
    height: 34px;
    padding: 0 8px;
    border-radius: 8px;
    border: 1.5px solid var(--pp-border);
    background: var(--pp-surface);
    color: var(--pp-text-secondary);
    font-size: 0.8rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.15s;
}
.pp-practice-page-btn:hover {
    border-color: var(--pp-purple);
    color: var(--pp-purple);
    background: var(--pp-purple-glow);
}
.pp-practice-page-btn.active {
    background: var(--pp-purple);
    color: #fff;
    border-color: var(--pp-purple);
}
.pp-practice-page-btn.answered {
    background: var(--pp-green-light);
    color: var(--pp-green);
    border-color: rgba(5, 150, 105, 0.2);
}

/* ---- Question card ---- */
.pp-practice-card {
    background: var(--pp-surface);
    border: 1px solid var(--pp-border);
    border-radius: 14px;
    padding: 1.5rem 1.75rem;
    box-shadow: var(--pp-shadow-card);
    margin-bottom: 16px;
}
.pp-practice-card-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}
.pp-practice-card-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--pp-purple);
    color: #fff;
    font-weight: 800;
    font-size: 0.78rem;
    flex-shrink: 0;
}
.pp-practice-card-body {
    font-size: 0.9rem;
    line-height: 1.7;
    color: var(--pp-text);
}

/* ---- Answer ---- */
.pp-practice-answer {
    margin-top: 12px;
    padding: 14px 16px;
    background: var(--pp-teal-light);
    border: 1px solid rgba(13, 148, 136, 0.12);
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 500;
    line-height: 1.65;
    color: var(--pp-text-secondary);
    display: none;
}
.pp-practice-answer.shown {
    display: block;
}

/* ---- Actions ---- */
.pp-practice-actions {
    margin-top: 12px;
}
.pp-practice-reveal-btn {
    display: block;
    width: 100%;
    padding: 0.7rem;
    border: 1.5px solid var(--pp-purple);
    border-radius: 10px;
    background: transparent;
    color: var(--pp-purple);
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s;
}
.pp-practice-reveal-btn:hover {
    background: var(--pp-purple-light);
}
.pp-practice-reveal-btn.revealed {
    background: var(--pp-purple-glow);
    border-color: rgba(124, 58, 237, 0.25);
    color: var(--pp-purple);
}

/* ---- Navigation (Previous / Next) ---- */
.pp-practice-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-top: 8px;
}
.pp-practice-nav-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 10px;
    font-size: 13px;
    font-weight: 600;
    color: var(--pp-purple);
    background: var(--pp-purple-glow);
    border: 1px solid rgba(124, 58, 237, 0.15);
    cursor: pointer;
    transition: all 0.2s;
}
.pp-practice-nav-btn:hover:not(:disabled) {
    background: rgba(124, 58, 237, 0.14);
    border-color: rgba(124, 58, 237, 0.3);
}
.pp-practice-nav-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
}
.pp-practice-nav-btn svg {
    flex-shrink: 0;
}

/* ---- Dark theme overrides ---- */
[data-theme="dark"] .pp-practice-card {
    background: var(--pp-surface);
    border-color: var(--pp-border);
}
[data-theme="dark"] .pp-practice-card-num {
    background: var(--pp-surface-raised);
    border: 1.5px solid var(--pp-purple);
    color: var(--pp-purple);
}
[data-theme="dark"] .pp-practice-page-btn {
    background: var(--pp-surface);
    border-color: var(--pp-border);
}
[data-theme="dark"] .pp-practice-page-btn.active {
    background: transparent;
    border-color: var(--pp-purple);
    color: var(--pp-purple);
}
[data-theme="dark"] .pp-practice-page-btn.answered {
    background: rgba(52, 211, 153, 0.06);
    color: #34D399;
    border-color: rgba(52, 211, 153, 0.15);
}
[data-theme="dark"] .pp-practice-answer {
    background: rgba(52, 211, 153, 0.03);
    border-color: rgba(52, 211, 153, 0.08);
}
[data-theme="dark"] .pp-practice-reveal-btn {
    border-color: rgba(167, 139, 250, 0.3);
    color: #C4B5FD;
}
[data-theme="dark"] .pp-practice-reveal-btn:hover {
    background: rgba(167, 139, 250, 0.04);
}
[data-theme="dark"] .pp-practice-nav-btn {
    background: var(--pp-surface);
    border-color: var(--pp-border);
    color: #C4B5FD;
}
[data-theme="dark"] .pp-practice-nav-btn:hover:not(:disabled) {
    background: var(--pp-surface-raised);
    border-color: rgba(167, 139, 250, 0.3);
}

/* ---- Mobile ---- */
@media (max-width: 700px) {
    .pp-practice-card { padding: 1.1rem; }
    .pp-practice-pages { gap: 4px; }
    .pp-practice-page-btn { min-width: 30px; height: 30px; font-size: 0.72rem; }
    .pp-practice-nav { gap: 8px; }
    .pp-practice-nav-btn { padding: 6px 10px; font-size: 12px; }
}