:root {
    --primary: #3CB4E5;
    --primary-dark: #2898c8;
    --primary-navy: #1a365d;
    --primary-light: #5FC8F0;
    --primary-lighter: #E8F4F8;
    --accent: #f5a623;
    --accent-dark: #d68f1d;
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-900: #111827;
    --white: #ffffff;
    --success: #10b981;
    --error: #ef4444;
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    --radius-full: 9999px;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --transition-base: 0.3s ease;
}

body.pvp-app {
    margin: 0;
    font-family: 'Inter', sans-serif;
    background: var(--gray-50);
    color: var(--gray-700);
    line-height: 1.7;
}

.page-header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: var(--spacing-2xl) var(--spacing-md);
    padding-top: calc(var(--spacing-2xl) + 80px);
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.page-header h1 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    margin: 0 0 var(--spacing-md);
}

.page-header p {
    font-size: 1.15rem;
    opacity: 0.95;
    max-width: 720px;
    margin: 0 auto;
}

.page-header .btn-primary {
    background: #fff;
    color: var(--primary-navy);
    border: none;
}

.page-header .btn-primary:hover {
    background: var(--primary-lighter);
    color: var(--primary-navy);
}

.page-header .btn-outline {
    background: transparent;
    color: #fff;
    border: 2px solid #fff;
}

.page-header .btn-outline:hover {
    background: rgba(255,255,255,0.15);
    color: #fff;
}

.lessons-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md) var(--spacing-2xl);
}

.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-xl);
    margin-top: var(--spacing-xl);
}

.lesson-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: var(--spacing-xl);
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all var(--transition-base);
    cursor: pointer;
    border: 2px solid transparent;
    text-align: left;
}

.lesson-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 30px rgba(60, 180, 229, 0.2);
    border-color: var(--primary);
}

.lesson-icon {
    width: 64px;
    height: 64px;
    background: linear-gradient(135deg, var(--primary-lighter) 0%, var(--primary-light) 100%);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    margin-bottom: var(--spacing-lg);
}

.lesson-card h3 {
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin: 0 0 var(--spacing-sm);
}

.lesson-card p {
    color: var(--gray-600);
    line-height: 1.7;
    margin: 0 0 var(--spacing-md);
}

.lesson-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.lesson-badge {
    display: inline-block;
    background: var(--primary-lighter);
    color: var(--primary-dark);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-full);
    font-size: 0.85rem;
    font-weight: 600;
}

.lesson-card.done {
    border-color: var(--success);
}

.lesson-card.done .lesson-badge.done-badge {
    background: #ecfdf5;
    color: #065f46;
}

.back-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    color: var(--primary);
    text-decoration: none;
    font-weight: 600;
    margin-bottom: var(--spacing-lg);
    transition: all var(--transition-base);
}

.back-link:hover {
    color: var(--primary-navy);
    transform: translateX(-5px);
}

.pvp-progress-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: 1.15rem 1.35rem;
    box-shadow: 0 2px 12px rgba(0,0,0,0.06);
}

.pvp-progress-label {
    font-size: 0.9rem;
    color: var(--gray-600);
    margin-bottom: 0.45rem;
    display: flex;
    justify-content: space-between;
    font-weight: 600;
}

.pvp-progress-bar {
    height: 8px;
    background: rgba(255,255,255,0.25);
    border-radius: 99px;
    overflow: hidden;
}

.pvp-progress-bar.light {
    background: var(--gray-200);
}

.pvp-progress-fill {
    height: 100%;
    background: var(--accent);
    border-radius: 99px;
    transition: width 0.4s ease;
    width: 0%;
}

.pvp-hero-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.pvp-badge {
    background: rgba(255,255,255,0.22);
    padding: 0.3rem 0.8rem;
    border-radius: 99px;
    font-size: 0.85rem;
    font-weight: 600;
}

/* Topic layout */
.pvp-layout {
    display: grid;
    grid-template-columns: 280px 1fr;
    min-height: calc(100vh - 80px);
    max-width: 1400px;
    margin: 0 auto;
    padding-top: 90px;
}

.pvp-sidebar {
    background: linear-gradient(180deg, var(--primary-navy) 0%, #152a4a 100%);
    color: #fff;
    padding: 1.25rem;
    position: sticky;
    top: 90px;
    height: calc(100vh - 90px);
    overflow-y: auto;
    border-radius: 0 var(--radius-xl) var(--radius-xl) 0;
}

.pvp-sidebar-header {
    margin-bottom: 1rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid rgba(255,255,255,0.15);
}

.pvp-sidebar-header h2 {
    margin: 0 0 0.35rem;
    font-size: 1.15rem;
    font-weight: 700;
    color: #fff;
}

.pvp-sidebar-header p {
    margin: 0;
    font-size: 0.82rem;
    opacity: 0.8;
}

.pvp-progress-wrap { margin-top: 0.75rem; }
.pvp-sidebar .pvp-progress-label { color: rgba(255,255,255,0.85); font-weight: 500; font-size: 0.8rem; }

.pvp-topic-list {
    list-style: none;
    margin: 0;
    padding: 0;
}

.pvp-topic-btn {
    width: 100%;
    text-align: left;
    background: transparent;
    border: none;
    color: rgba(255,255,255,0.85);
    padding: 0.65rem 0.75rem;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.9rem;
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
    transition: background 0.2s;
    font-family: inherit;
}

.pvp-topic-btn:hover { background: rgba(255,255,255,0.1); }

.pvp-topic-btn.active {
    background: rgba(60,180,229,0.35);
    color: #fff;
    font-weight: 600;
}

.pvp-topic-btn.done .pvp-check { color: var(--success); }
.pvp-topic-icon { flex-shrink: 0; }
.pvp-topic-text { flex: 1; min-width: 0; }
.pvp-topic-text small {
    display: block;
    font-size: 0.75rem;
    opacity: 0.7;
    font-weight: 400;
    margin-top: 0.1rem;
}
.pvp-check { font-size: 0.85rem; opacity: 0.4; flex-shrink: 0; }

.pvp-sidebar-footer {
    margin-top: 1.25rem;
    padding-top: 1rem;
    border-top: 1px solid rgba(255,255,255,0.15);
    font-size: 0.8rem;
}

.pvp-sidebar-footer p { margin: 0 0 0.5rem; opacity: 0.75; }
.pvp-sidebar-footer a { color: var(--primary-light); text-decoration: none; }
.pvp-sidebar-footer a:hover { text-decoration: underline; }

.pvp-main {
    padding: 0 2rem 3rem;
    overflow-x: hidden;
}

.pvp-hero {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    padding: 1.75rem 2rem;
    border-radius: var(--radius-xl);
    margin-bottom: 1.5rem;
    box-shadow: 0 8px 24px rgba(40, 152, 200, 0.25);
}

.pvp-hero h1 {
    margin: 0 0 0.4rem;
    font-size: clamp(1.5rem, 3vw, 2rem);
    font-weight: 800;
}

.pvp-hero p { margin: 0; opacity: 0.95; }

.pvp-content-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    margin-bottom: 1.5rem;
}

.pvp-content-card h2 {
    color: var(--primary-navy);
    margin: 0 0 1rem;
    font-size: 1.35rem;
    padding-bottom: 0.5rem;
    border-bottom: 3px solid var(--primary-lighter);
}

.pvp-content-body h2,
.pvp-content-body h2.official-h2,
.pvp-content-body .official-h2 {
    font-size: 0.92rem;
    font-weight: 800;
    letter-spacing: 0.03em;
    color: var(--primary-navy);
    margin: 1.35rem 0 0.2rem;
    padding: 0;
    border: none;
    line-height: 1.3;
}

.pvp-content-body > .official-h2:first-child {
    margin-top: 0.15rem;
}

.pvp-content-body h3,
.pvp-content-body h3.official-h3,
.pvp-content-body .official-h3 {
    font-size: 1.12rem;
    font-weight: 700;
    color: var(--primary-navy);
    margin: 0.85rem 0 0.4rem;
    padding: 0;
    border: none;
    line-height: 1.35;
}

.pvp-content-body .official-h3-sub {
    margin-top: 0.05rem;
    margin-bottom: 0.75rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--gray-700);
}

.pvp-content-body .data-table {
    font-size: 0.86rem;
}

.official-table caption,
.data-table caption {
    caption-side: bottom;
    text-align: left;
    font-weight: 600;
    font-size: 0.85rem;
    color: var(--gray-600);
    padding: 0.45rem 0 0;
}

.official-abbr-table td:first-child {
    font-weight: 700;
    white-space: nowrap;
    width: 7.5rem;
    color: var(--primary-navy);
}

.pvp-content-body ul, .pvp-content-body ol {
    padding-left: 1.25rem;
    margin: 0.75rem 0;
}

.pvp-content-body li { margin-bottom: 0.35rem; }
.pvp-content-body a { color: var(--primary-dark); }

.key-box, .warn-box {
    padding: 1rem 1.15rem;
    border-radius: var(--radius-md);
    margin: 1rem 0;
}

.key-box {
    background: var(--primary-lighter);
    border-left: 4px solid var(--primary);
}

.warn-box {
    background: #fff8e5;
    border-left: 4px solid var(--accent);
}

.key-box strong, .warn-box strong {
    display: block;
    margin-bottom: 0.35rem;
    color: var(--primary-navy);
}

.warn-box strong { color: #92400e; }

.compare-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin: 1rem 0;
}

.compare-card {
    background: var(--gray-50);
    border-radius: var(--radius-md);
    padding: 1rem;
    border: 1px solid var(--gray-200);
}

.compare-card.class-c { border-top: 3px solid var(--primary-navy); }
.compare-card.class-g { border-top: 3px solid var(--success); }

.compare-card h4 {
    margin: 0 0 0.5rem;
    color: var(--primary-navy);
    font-size: 1rem;
}

.compare-card ul {
    margin: 0;
    padding-left: 1.1rem;
    font-size: 0.9rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.88rem;
    margin: 1rem 0;
}

.data-table th, .data-table td {
    border: 1px solid var(--gray-200);
    padding: 0.55rem 0.65rem;
    text-align: left;
}

.data-table th {
    background: var(--primary-navy);
    color: #fff;
    font-weight: 600;
}

.data-table tr:nth-child(even) td { background: var(--gray-50); }

.table-note {
    font-size: 0.82rem;
    color: var(--gray-600);
    font-style: italic;
}

.pvp-quiz {
    background: var(--white);
    border: 2px solid var(--primary);
    border-radius: var(--radius-xl);
    padding: 1.75rem;
    box-shadow: 0 4px 20px rgba(60,180,229,0.12);
}

.pvp-quiz h2 {
    margin: 0 0 0.35rem;
    color: var(--primary-dark);
    font-size: 1.35rem;
}

.pvp-quiz-intro {
    color: var(--gray-600);
    margin: 0 0 1.25rem;
    font-size: 0.95rem;
}

.pvp-quiz-item {
    background: var(--gray-50);
    border-radius: var(--radius-lg);
    padding: 1.15rem;
    margin-bottom: 1rem;
    border-left: 4px solid var(--primary);
}

.pvp-quiz-item.answered-correct { border-left-color: var(--success); }
.pvp-quiz-item.answered-wrong { border-left-color: var(--error); }

.pvp-quiz-q {
    font-weight: 600;
    color: var(--gray-900);
    margin-bottom: 0.75rem;
}

.pvp-options {
    display: flex;
    flex-direction: column;
    gap: 0.45rem;
}

.pvp-option {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.55rem 0.75rem;
    background: var(--white);
    border: 2px solid var(--gray-200);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.15s;
    font-size: 0.92rem;
}

.pvp-option:hover:not(.disabled) {
    border-color: var(--primary);
    background: var(--primary-lighter);
}

.pvp-option.selected { border-color: var(--primary); background: var(--primary-lighter); }
.pvp-option.correct { border-color: var(--success); background: #ecfdf5; }
.pvp-option.wrong { border-color: var(--error); background: #fef2f2; }
.pvp-option.disabled { cursor: default; opacity: 0.85; }

.pvp-explain {
    margin-top: 0.65rem;
    padding: 0.65rem 0.85rem;
    background: #ecfdf5;
    border-radius: var(--radius-md);
    font-size: 0.88rem;
    color: #065f46;
    display: none;
}

.pvp-explain.show { display: block; }

.pvp-quiz-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.25rem;
    align-items: center;
}

.pvp-quiz-score {
    font-weight: 700;
    color: var(--primary-dark);
}

.pvp-nav-bottom {
    display: flex;
    justify-content: space-between;
    margin-top: 1.5rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.pvp-result-banner {
    text-align: center;
    padding: 1.5rem;
    border-radius: var(--radius-lg);
    margin-top: 1rem;
    display: none;
}

.pvp-result-banner.show { display: block; }
.pvp-result-banner.pass { background: #ecfdf5; color: #065f46; }
.pvp-result-banner.fail { background: #fff8e5; color: #92400e; }
.pvp-result-banner h3 { margin: 0 0 0.35rem; }

.official-source-note {
    font-size: 0.85rem;
    color: var(--gray-600);
    background: var(--primary-lighter);
    border-left: 4px solid var(--primary);
    padding: 0.75rem 1rem;
    border-radius: var(--radius-md);
    margin: 0 0 1.25rem;
}

.official-p {
    margin: 0 0 0.75rem;
    text-align: left;
    font-size: 0.98rem;
    line-height: 1.65;
    color: var(--gray-700);
}

.official-num {
    padding-left: 1.1rem;
    text-indent: -1.1rem;
}
.official-note {
    background: #fff8e5;
    border-left: 4px solid var(--accent);
    padding: 0.85rem 1rem;
    border-radius: var(--radius-md);
    margin: 0.85rem 0;
}

.official-fig {
    margin: 1.25rem 0;
    text-align: center;
}

.official-fig img {
    max-width: 100%;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: 0 2px 12px rgba(0,0,0,0.08);
    background: #fff;
}

.official-fig figcaption {
    margin-top: 0.45rem;
    font-size: 0.85rem;
    color: var(--gray-600);
    font-weight: 600;
}

.aip-link {
    display: inline-block;
    margin: 0.25rem 0.5rem 0.25rem 0;
    color: var(--primary-dark);
    font-weight: 600;
}

.aip-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1rem;
    margin: 1rem 0;
}

.aip-card {
    display: block;
    background: var(--white);
    border: 1px solid var(--gray-200);
    border-radius: var(--radius-lg);
    overflow: hidden;
    text-decoration: none;
    color: var(--primary-navy);
    font-weight: 600;
    font-size: 0.88rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

.aip-card img {
    width: 100%;
    height: 140px;
    object-fit: cover;
    display: block;
    background: var(--gray-100);
}

.aip-card span { display: block; padding: 0.7rem 0.8rem; }

.pvp-topics-toggle {
    display: none;
    position: sticky;
    top: 86px;
    z-index: 20;
    margin: 0 1rem 0.75rem;
    width: calc(100% - 2rem);
    padding: 0.7rem 1rem;
    border: none;
    border-radius: var(--radius-md);
    background: var(--primary-navy);
    color: #fff;
    font-weight: 700;
    font-family: inherit;
    font-size: 1rem;
}

.pvp-sidebar-backdrop {
    display: none;
}

.hidden { display: none !important; }

@media (max-width: 900px) {
    .pvp-layout { grid-template-columns: 1fr; padding-top: 80px; }
    .pvp-topics-toggle { display: block; }
    .pvp-sidebar-backdrop:not([hidden]) {
        display: block;
        position: fixed;
        inset: 0;
        background: rgba(15, 23, 42, 0.45);
        z-index: 30;
    }
    .pvp-sidebar {
        position: fixed;
        top: 0;
        left: 0;
        bottom: 0;
        width: min(88vw, 320px);
        height: 100vh;
        z-index: 40;
        transform: translateX(-105%);
        transition: transform 0.25s ease;
        border-radius: 0;
    }
    .pvp-sidebar.open { transform: translateX(0); }
    .pvp-main { padding: 0 1rem 2rem; }
    .pvp-content-card { padding: 1.15rem; }
    .compare-grid { grid-template-columns: 1fr; }
    .data-table { font-size: 0.78rem; }
    .official-p { text-align: left; }
    .official-abbr-table td:first-child { white-space: normal; }
    .pvp-option { min-height: 44px; }
}

@media (max-width: 600px) {
    .pvp-hero { padding: 1.25rem; }
    .pvp-nav-bottom { flex-direction: column; }
    .pvp-nav-bottom .btn { width: 100%; text-align: center; }
    .lessons-grid { grid-template-columns: 1fr; }
}

/* VFR chart page — same chrome as the handbook */
body.vfr-map-page {
    --nav-h: 112px;
    background: var(--gray-50);
}

body.vfr-map-page .page-header {
    padding-top: calc(var(--spacing-2xl) + var(--nav-h));
    margin-bottom: var(--spacing-xl);
}

.vfr-edition {
    display: inline-block;
    text-align: left;
    background: rgba(255,255,255,0.16);
    border: 1px solid rgba(255,255,255,0.4);
    border-radius: var(--radius-lg);
    padding: 0.9rem 1.2rem;
    margin: 1.25rem auto 0;
    max-width: 36rem;
}

.vfr-edition strong {
    display: block;
    font-size: 1.15rem;
    font-weight: 800;
    margin-bottom: 0.2rem;
}

.vfr-edition span {
    display: block;
    font-size: 0.92rem;
    opacity: 0.95;
    line-height: 1.45;
}

.vfr-map-card {
    background: var(--white);
    border-radius: var(--radius-xl);
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    overflow: hidden;
    margin-bottom: var(--spacing-xl);
}

.vfr-map-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    align-items: center;
    padding: 0.85rem 1rem;
    border-bottom: 1px solid var(--gray-200);
    background: var(--gray-50);
}

.vfr-map-toolbar .btn {
    padding: 0.45rem 0.9rem;
    font-size: 0.9rem;
    font-weight: 700;
}

.vfr-map-toolbar .vfr-zoom {
    display: flex;
    gap: 0.35rem;
}

.vfr-viewer {
    height: min(72vh, 820px);
    min-height: 420px;
    background: var(--primary-lighter);
    position: relative;
}

.vfr-hint {
    position: absolute;
    left: 50%;
    bottom: 1rem;
    transform: translateX(-50%);
    z-index: 5;
    background: rgba(26, 54, 93, 0.88);
    color: #fff;
    font-size: 0.8rem;
    padding: 0.4rem 0.75rem;
    border-radius: 999px;
    pointer-events: none;
    transition: opacity 0.6s ease;
}

.vfr-hint.hide { opacity: 0; }

.vfr-map-meta {
    padding: 0.85rem 1.15rem 1rem;
    font-size: 0.88rem;
    color: var(--gray-600);
    border-top: 1px solid var(--gray-200);
}

.vfr-map-meta strong { color: var(--primary-navy); }

@media (max-width: 700px) {
    .vfr-viewer { height: 62vh; min-height: 360px; }
    .vfr-map-toolbar .btn { min-height: 42px; }
}