/* ============================================================
   开发说明页 - 统一设计系统
   字体: 与 style.css 保持一致 (-apple-system, Microsoft YaHei...)
   字号: 11 / 12 / 13 / 14 / 18 / 24 px (6级)
   间距: 基于 4px 节奏 (4/8/12/16/20/24/32/40/48)
   色彩: #1e293b 正文 | #64748b 辅助 | #94a3b8 弱化 | #3b82f6 强调
   ============================================================ */

/* ===== 全局字体 ===== */
.tutorial-layout,
.tutorial-layout * {
    font-family: -apple-system, "Microsoft YaHei", "PingFang SC", "Segoe UI", sans-serif;
}

/* ===== 整体布局 ===== */
.tutorial-layout { display: flex; min-height: 100vh; padding-top: 64px; }

/* ===== 左侧侧边栏 ===== */
.tutorial-sidebar {
    width: 220px; flex-shrink: 0; position: fixed; top: 64px; left: 0; bottom: 0;
    overflow-y: auto; z-index: 40;
    background: transparent;
    border-right: 1px solid rgba(0,0,0,0.04);
}
.tutorial-sidebar::-webkit-scrollbar { width: 0; }

.sidebar-header {
    padding: 20px 16px 14px;
    border-bottom: 1px solid rgba(0,0,0,0.04);
}
.sidebar-header h3 { font-size: 12px; font-weight: 600; color: #1e293b; }
.sidebar-header p { font-size: 11px; color: #94a3b8; margin-top: 2px; }
.sidebar-search { margin-top: 10px; }
.sidebar-search-input {
    width: 100%; height: 30px; border-radius: 6px;
    border: 1px solid rgba(0,0,0,0.06);
    background: rgba(0,0,0,0.015);
    padding: 0 10px; font-size: 12px; color: #1e293b;
    outline: none; transition: all 0.15s;
}
.sidebar-search-input::placeholder { color: #cbd5e1; }
.sidebar-search-input:focus {
    border-color: rgba(59,130,246,0.3);
    box-shadow: 0 0 0 2px rgba(59,130,246,0.06);
    background: #fff;
}

.sidebar-nav { padding: 10px 0; }
.sidebar-group { margin-bottom: 0; }
.sidebar-group.is-hidden { display: none; }
.sidebar-group-title {
    padding: 12px 16px 4px; font-size: 11px; font-weight: 600;
    color: #94a3b8; letter-spacing: 0.3px;
}
.sidebar-group-title::before { display: none; }

.sidebar-item {
    display: flex; align-items: center; gap: 8px;
    padding: 6px 16px; margin: 1px 4px; border-radius: 4px;
    font-size: 12px; color: #64748b; transition: all 0.12s;
    cursor: pointer; text-decoration: none; line-height: 1.4;
}
.sidebar-item:hover { background: rgba(0,0,0,0.025); color: #1e293b; }
.sidebar-item.active {
    background: rgba(59,130,246,0.06); color: #2563eb; font-weight: 500;
}
.sidebar-item.disabled { opacity: 0.35; pointer-events: none; }

.sidebar-dot { width: 4px; height: 4px; border-radius: 50%; background: #d1d5db; flex-shrink: 0; }
.sidebar-item.active .sidebar-dot { background: #3b82f6; }
.sidebar-item:hover .sidebar-dot { background: #9ca3af; }

.sidebar-badge {
    margin-left: auto; font-size: 9px; padding: 1px 5px; border-radius: 4px;
    background: rgba(0,0,0,0.03); color: #94a3b8; font-weight: 500; white-space: nowrap;
}

/* ===== 右侧主内容 ===== */
.tutorial-main { flex: 1; margin-left: 220px; min-height: 100vh; }

.tutorial-section {
    padding: 40px 48px 56px; max-width: 720px;
    contain: layout paint style; display: none;
}
.tutorial-section.is-active { display: block; }

/* ===== 章节头部 ===== */
.tutorial-header {
    margin-bottom: 32px; padding-bottom: 16px;
    border-bottom: 1px solid rgba(0,0,0,0.05);
}
.tutorial-breadcrumb {
    font-size: 11px; color: #94a3b8; margin-bottom: 6px;
}
.tutorial-header h2 {
    font-size: 18px; font-weight: 700; color: #1e293b; margin-bottom: 8px;
    letter-spacing: -0.2px;
}
.tutorial-header p {
    font-size: 13px; color: #64748b; line-height: 1.65;
}

/* ===== 产品说明 Hero ===== */
.hero-clean {
    max-width: 480px; margin: 0 auto;
    padding: 80px 32px 72px; text-align: center;
}
.hero-clean-title {
    font-size: 36px; font-weight: 800; color: #1e293b;
    line-height: 1.2; margin-bottom: 16px; letter-spacing: -0.5px;
}
.hero-clean-sub { font-size: 14px; color: #94a3b8; margin-bottom: 0; }
.hero-divider {
    width: 32px; height: 2px;
    background: linear-gradient(90deg, #3b82f6, transparent);
    margin: 24px auto; border-radius: 1px;
}
.hero-clean-answer { font-size: 20px; font-weight: 500; color: #475569; margin-bottom: 6px; }
.hero-clean-answer em { font-style: normal; color: #3b82f6; font-weight: 700; }
.hero-clean-desc {
    font-size: 12px; color: #3b82f6; letter-spacing: 2px;
    margin-bottom: 40px; font-weight: 600; text-transform: uppercase;
}
.hero-clean-btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 12px 28px; border-radius: 8px;
    background: #1e293b; color: #fff; text-decoration: none;
    font-size: 13px; font-weight: 600;
    transition: all 0.2s; box-shadow: 0 1px 3px rgba(0,0,0,0.12);
}
.hero-clean-btn:hover {
    background: #334155; transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.hero-clean-btn svg { flex-shrink: 0; opacity: 0.8; }

/* ===== Overview 卡片 ===== */
.overview-hero, .overview-grid { display: grid; gap: 16px; margin-bottom: 20px; }
.overview-hero { grid-template-columns: repeat(2, 1fr); }
.overview-grid { grid-template-columns: repeat(3, 1fr); }
.overview-card {
    background: #fff; border: 1px solid rgba(0,0,0,0.04);
    border-radius: 10px; padding: 20px;
}
.overview-card-primary {
    background: linear-gradient(135deg, rgba(59,130,246,0.04), rgba(139,92,246,0.04));
    border-color: rgba(59,130,246,0.08);
}
.overview-card h3 { font-size: 14px; font-weight: 700; color: #1e293b; margin-bottom: 8px; }
.overview-card p { font-size: 13px; color: #64748b; line-height: 1.7; }
.overview-list { margin: 0; padding-left: 16px; }
.overview-list li { color: #64748b; font-size: 13px; line-height: 1.9; }

/* ===== Doc Meta Card ===== */
.doc-meta-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 24px; }
.doc-meta-card {
    background: rgba(248,250,252,0.8); border: 1px solid rgba(0,0,0,0.04);
    border-radius: 8px; padding: 16px;
}
.doc-meta-card h3 { font-size: 13px; font-weight: 600; color: #1e293b; margin-bottom: 6px; }
.doc-meta-card p { font-size: 12px; line-height: 1.7; color: #64748b; }

.doc-actions { display: flex; align-items: center; justify-content: space-between; gap: 12px; margin-top: 16px; flex-wrap: wrap; }
.doc-current { font-size: 12px; color: #64748b; padding: 6px 10px; border-radius: 6px; background: rgba(59,130,246,0.05); }
.doc-link-btn {
    border: 1px solid rgba(59,130,246,0.12); background: #fff; color: #3b82f6;
    padding: 6px 12px; border-radius: 6px; font-size: 12px; font-weight: 500; cursor: pointer; transition: all 0.15s;
}
.doc-link-btn:hover { background: rgba(59,130,246,0.04); border-color: rgba(59,130,246,0.2); }

.doc-insights { display: grid; grid-template-columns: repeat(4, 1fr); gap: 10px; margin-top: 16px; }
.doc-insight { background: rgba(248,250,252,0.8); border: 1px solid rgba(0,0,0,0.04); border-radius: 8px; padding: 12px; }
.doc-insight span { display: block; font-size: 11px; color: #94a3b8; margin-bottom: 4px; }
.doc-insight strong { display: block; font-size: 13px; color: #1e293b; }
.doc-insight-status strong { color: #3b82f6; }

.doc-summary { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 12px; }
.doc-summary-card { background: rgba(248,250,252,0.8); border: 1px solid rgba(0,0,0,0.04); border-radius: 8px; padding: 14px; }
.doc-summary-card span { display: block; font-size: 11px; color: #94a3b8; margin-bottom: 6px; }
.doc-summary-card strong { display: block; font-size: 13px; line-height: 1.6; color: #1e293b; }

.doc-notes { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 12px; }
.doc-note-card { background: rgba(59,130,246,0.03); border: 1px solid rgba(59,130,246,0.06); border-radius: 8px; padding: 14px; }
.doc-note-card span { display: block; font-size: 11px; color: #94a3b8; margin-bottom: 6px; }
.doc-note-card strong { display: block; font-size: 13px; line-height: 1.6; color: #1e293b; }

.doc-faq { display: grid; grid-template-columns: repeat(2, 1fr); gap: 10px; margin-top: 12px; }
.doc-faq-item { background: rgba(248,250,252,0.8); border: 1px solid rgba(0,0,0,0.04); border-radius: 8px; padding: 14px; }
.doc-faq-item span, .doc-related-title { display: block; font-size: 11px; color: #94a3b8; margin-bottom: 6px; }
.doc-faq-item strong { display: block; font-size: 13px; line-height: 1.6; color: #1e293b; margin-bottom: 6px; }
.doc-faq-item p { font-size: 12px; line-height: 1.7; color: #64748b; }

.doc-appendix { margin-top: 24px; }
.doc-appendix .doc-meta-grid, .doc-appendix .doc-insights, .doc-appendix .doc-summary, .doc-appendix .doc-notes, .doc-appendix .doc-faq { margin-top: 0; margin-bottom: 0; }
.doc-appendix > * + * { margin-top: 12px; }

.doc-related { margin-top: 24px; }
.doc-related-links { display: flex; flex-wrap: wrap; gap: 8px; }
.doc-related-link {
    display: inline-flex; align-items: center; padding: 6px 12px; border-radius: 6px;
    text-decoration: none; color: #3b82f6; background: rgba(59,130,246,0.04);
    border: 1px solid rgba(59,130,246,0.08); font-size: 12px; font-weight: 500; transition: all 0.15s;
}
.doc-related-link:hover { background: rgba(59,130,246,0.08); border-color: rgba(59,130,246,0.16); }

/* ===== 步骤卡片 ===== */
.steps { position: relative; }
.steps::before {
    content: ''; position: absolute; left: 11px; top: 24px; bottom: 24px; width: 1px;
    background: rgba(0,0,0,0.05);
}

.step { display: flex; gap: 16px; margin-bottom: 4px; position: relative; padding: 12px 0; }
.step:last-child { margin-bottom: 0; }

.tutorial-section.animate-steps .step {
    opacity: 0; transform: translateY(8px);
    animation: stepFadeIn 0.3s ease forwards;
}
.tutorial-section.animate-steps .step:nth-child(1) { animation-delay: 0.03s; }
.tutorial-section.animate-steps .step:nth-child(2) { animation-delay: 0.06s; }
.tutorial-section.animate-steps .step:nth-child(3) { animation-delay: 0.09s; }
.tutorial-section.animate-steps .step:nth-child(4) { animation-delay: 0.12s; }
.tutorial-section.animate-steps .step:nth-child(5) { animation-delay: 0.15s; }
.tutorial-section.animate-steps .step:nth-child(6) { animation-delay: 0.18s; }
.tutorial-section.animate-steps .step:nth-child(7) { animation-delay: 0.21s; }
.tutorial-section.animate-steps .step:nth-child(8) { animation-delay: 0.24s; }
.tutorial-section.animate-steps .step:nth-child(9) { animation-delay: 0.27s; }
@keyframes stepFadeIn { to { opacity: 1; transform: translateY(0); } }

.step-number {
    flex-shrink: 0; width: 22px; height: 22px; border-radius: 50%;
    background: #f97316; color: #fff; font-size: 11px; font-weight: 600;
    display: flex; align-items: center; justify-content: center;
    position: relative; z-index: 1;
}
.step:nth-child(2) .step-number,
.step:nth-child(3) .step-number,
.step:nth-child(4) .step-number,
.step:nth-child(5) .step-number,
.step:nth-child(6) .step-number,
.step:nth-child(7) .step-number,
.step:nth-child(8) .step-number,
.step:nth-child(9) .step-number { background: #f97316; color: #fff; box-shadow: none; }

.step-body {
    flex: 1; padding: 0;
    background: transparent; border: none; border-radius: 0;
    content-visibility: auto; contain-intrinsic-size: auto 120px;
}
.step-body:hover { border-color: transparent; box-shadow: none; }
.step-body h3 { font-size: 13px; font-weight: 600; color: #1e293b; margin-bottom: 4px; line-height: 1.4; }
.step-body p { font-size: 13px; color: #475569; line-height: 1.65; margin-bottom: 8px; }
.step-body p:last-child { margin-bottom: 0; }
.step-list { margin: 4px 0 8px 0; padding-left: 16px; }
.step-list li {
    font-size: 13px; color: #475569; line-height: 1.8;
    list-style: none; position: relative; padding-left: 12px;
}
.step-list li::before { content: '–'; position: absolute; left: 0; color: #94a3b8; }
.step-list li strong { color: #1e293b; font-weight: 600; }

/* ===== 步骤内列表(ul/ol)统一格式 ===== */
.step-body ul,
.step-body ol {
    margin: 8px 0; padding-left: 20px;
    font-size: 13px; color: #475569; line-height: 1.8;
}
.step-body ul li,
.step-body ol li { margin-bottom: 2px; }
.step-body ul li strong,
.step-body ol li strong { color: #1e293b; font-weight: 600; }

/* ===== 辅助文本 ===== */
.text-secondary { color: #64748b; font-size: 13px; line-height: 1.65; margin-top: 8px; }

/* ===== Mermaid 图表容器 ===== */
.step-body .mermaid,
.tutorial-section > .mermaid {
    margin: 12px 0; background: rgba(0,0,0,0.02);
    border-radius: 8px; padding: 16px; border: 1px solid rgba(0,0,0,0.04);
    font-size: 12px; overflow-x: auto;
}

/* ===== 步骤图片 ===== */
.step-img {
    border-radius: 8px; overflow: hidden;
    box-shadow: 0 1px 4px rgba(0,0,0,0.06);
    border: 1px solid rgba(0,0,0,0.06); margin-top: 12px;
    cursor: zoom-in; transition: all 0.2s;
    position: relative; max-width: 560px;
    content-visibility: auto; contain-intrinsic-size: 360px 200px;
}
.step-img::after {
    content: '🔍 点击放大'; position: absolute; bottom: 6px; right: 10px;
    background: rgba(0,0,0,0.6); color: #fff; font-size: 10px;
    padding: 2px 8px; border-radius: 4px; opacity: 0; transition: opacity 0.2s;
}
.step-img:hover::after { opacity: 1; }
.step-img:hover { box-shadow: 0 4px 16px rgba(0,0,0,0.1); }
.step-img img { width: 100%; height: auto; display: block; }

/* ===== 提示框 ===== */
.step-tip {
    background: rgba(59,130,246,0.03);
    border-left: 2px solid #93c5fd; padding: 8px 12px;
    border-radius: 0 4px 4px 0; margin: 4px 0 8px;
    font-size: 12px; color: #475569; line-height: 1.6;
}
.step-tip strong { color: #1e293b; }

/* ===== 翻页 ===== */
.doc-pagination { display: grid; grid-template-columns: repeat(2, 1fr); gap: 12px; margin-top: 32px; }
.doc-page-link {
    display: flex; flex-direction: column; gap: 4px; padding: 14px 16px;
    border-radius: 8px; border: 1px solid rgba(0,0,0,0.05); background: #fff;
    text-decoration: none; transition: all 0.15s;
}
.doc-page-link span { font-size: 11px; color: #94a3b8; }
.doc-page-link strong { font-size: 13px; color: #1e293b; }
.doc-page-link:hover { border-color: rgba(59,130,246,0.15); box-shadow: 0 2px 8px rgba(0,0,0,0.04); }
.doc-page-link.disabled { pointer-events: none; opacity: 0.5; background: rgba(0,0,0,0.01); }

/* ===== Lightbox ===== */
.lightbox {
    display: none; position: fixed; inset: 0; z-index: 1000;
    background: rgba(0,0,0,0.88); align-items: center; justify-content: center;
    cursor: zoom-out; backdrop-filter: blur(4px);
}
.lightbox.active { display: flex; }
.lightbox img { max-width: 90vw; max-height: 90vh; border-radius: 6px; }
.lightbox-close { position: absolute; top: 16px; right: 24px; color: #fff; font-size: 32px; cursor: pointer; opacity: 0.5; transition: opacity 0.15s; font-weight: 300; }
.lightbox-close:hover { opacity: 1; }

/* ===== 移动端 ===== */
.sidebar-toggle {
    display: none; position: fixed; bottom: 20px; left: 20px; z-index: 60;
    width: 40px; height: 40px; border-radius: 10px;
    background: #1e293b; color: #fff; border: none; font-size: 18px; cursor: pointer;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}

@media (max-width: 768px) {
    .tutorial-sidebar { transform: translateX(-100%); transition: transform 0.2s; width: 220px; background: #fff; }
    .tutorial-sidebar.open { transform: translateX(0); box-shadow: 2px 0 12px rgba(0,0,0,0.08); }
    .tutorial-main { margin-left: 0; }
    .tutorial-section { padding: 24px 16px 40px; }
    .overview-hero, .overview-grid, .doc-meta-grid, .doc-insights, .doc-summary, .doc-notes, .doc-faq { grid-template-columns: 1fr; }
    .doc-pagination { grid-template-columns: 1fr; }
    .sidebar-toggle { display: flex; align-items: center; justify-content: center; }
    .step { gap: 12px; }
    .step-number { width: 20px; height: 20px; font-size: 10px; }
    .tutorial-header h2 { font-size: 16px; }
    .hero-clean { padding: 56px 20px 48px; }
    .hero-clean-title { font-size: 28px; }
    .hero-clean-answer { font-size: 18px; }
}
@media (min-width: 769px) { .sidebar-toggle { display: none; } }

@media (prefers-reduced-motion: reduce) {
    .step, .tutorial-section.animate-steps .step, .doc-page-link, .doc-related-link,
    .step-body, .step-img, .lightbox, .sidebar-item, .sidebar-search-input {
        animation: none !important; transition: none !important; transform: none !important;
    }
}

/* ===== 暗黑模式 ===== */
body.dark .tutorial-sidebar { border-right-color: rgba(255,255,255,0.04); }
body.dark .sidebar-header { border-bottom-color: rgba(255,255,255,0.04); }
body.dark .sidebar-header h3 { color: #e2e8f0; }
body.dark .sidebar-header p { color: #64748b; }
body.dark .sidebar-search-input {
    background: rgba(255,255,255,0.03); border-color: rgba(255,255,255,0.06); color: #e2e8f0;
}
body.dark .sidebar-search-input::placeholder { color: #475569; }
body.dark .sidebar-search-input:focus {
    background: rgba(255,255,255,0.05); border-color: rgba(96,165,250,0.2);
    box-shadow: 0 0 0 2px rgba(96,165,250,0.06);
}
body.dark .sidebar-group-title { color: #64748b; }
body.dark .sidebar-item { color: #94a3b8; }
body.dark .sidebar-item:hover { background: rgba(255,255,255,0.03); color: #e2e8f0; }
body.dark .sidebar-item.active { background: rgba(96,165,250,0.08); color: #60a5fa; }
body.dark .sidebar-dot { background: #475569; }
body.dark .sidebar-item.active .sidebar-dot { background: #60a5fa; }
body.dark .sidebar-badge { background: rgba(255,255,255,0.03); color: #64748b; }

body.dark .tutorial-breadcrumb { color: #64748b; }
body.dark .tutorial-header h2 { color: #e2e8f0; }
body.dark .tutorial-header p { color: #94a3b8; }
body.dark .tutorial-header { border-bottom-color: rgba(255,255,255,0.04); }

body.dark .overview-card { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .overview-card-primary { background: rgba(96,165,250,0.04); border-color: rgba(96,165,250,0.08); }
body.dark .overview-card h3 { color: #e2e8f0; }
body.dark .overview-card p, body.dark .overview-list li { color: #94a3b8; }

body.dark .doc-meta-card { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .doc-meta-card h3 { color: #e2e8f0; }
body.dark .doc-meta-card p { color: #94a3b8; }
body.dark .doc-current { background: rgba(96,165,250,0.06); color: #94a3b8; }
body.dark .doc-link-btn { background: transparent; color: #60a5fa; border-color: rgba(96,165,250,0.12); }
body.dark .doc-link-btn:hover { background: rgba(96,165,250,0.06); }
body.dark .doc-insight { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .doc-insight span { color: #64748b; }
body.dark .doc-insight strong { color: #e2e8f0; }
body.dark .doc-insight-status strong { color: #60a5fa; }
body.dark .doc-summary-card { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .doc-summary-card span { color: #64748b; }
body.dark .doc-summary-card strong { color: #e2e8f0; }
body.dark .doc-note-card { background: rgba(96,165,250,0.03); border-color: rgba(96,165,250,0.06); }
body.dark .doc-note-card span { color: #64748b; }
body.dark .doc-note-card strong { color: #e2e8f0; }
body.dark .doc-faq-item { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .doc-faq-item span, body.dark .doc-related-title { color: #64748b; }
body.dark .doc-faq-item strong { color: #e2e8f0; }
body.dark .doc-faq-item p { color: #94a3b8; }
body.dark .doc-related-link { color: #60a5fa; background: rgba(96,165,250,0.04); border-color: rgba(96,165,250,0.08); }
body.dark .doc-related-link:hover { background: rgba(96,165,250,0.08); border-color: rgba(96,165,250,0.12); }

body.dark .step-number { background: #f97316; color: #fff; }
body.dark .step-body h3 { color: #e2e8f0; }
body.dark .step-body p { color: #94a3b8; }
body.dark .step-list li { color: #94a3b8; }
body.dark .step-list li strong { color: #e2e8f0; }
body.dark .steps::before { background: rgba(255,255,255,0.04); }
body.dark .step-img { border-color: rgba(255,255,255,0.04); box-shadow: 0 1px 4px rgba(0,0,0,0.3); }
body.dark .step-tip { background: rgba(96,165,250,0.04); border-left-color: rgba(96,165,250,0.3); color: #94a3b8; }
body.dark .step-tip strong { color: #e2e8f0; }
body.dark .step-body ul, body.dark .step-body ol { color: #94a3b8; }
body.dark .step-body ul li strong, body.dark .step-body ol li strong { color: #e2e8f0; }
body.dark .text-secondary { color: #64748b; }
body.dark .step-body .mermaid,
body.dark .tutorial-section > .mermaid { background: rgba(255,255,255,0.03); border-color: rgba(255,255,255,0.04); }

body.dark .doc-page-link { background: rgba(255,255,255,0.02); border-color: rgba(255,255,255,0.04); }
body.dark .doc-page-link span { color: #64748b; }
body.dark .doc-page-link strong { color: #e2e8f0; }
body.dark .doc-page-link:hover { border-color: rgba(96,165,250,0.12); }
body.dark .doc-page-link.disabled { background: rgba(255,255,255,0.01); }

/* ===== Hero 暗黑模式 ===== */
body.dark .hero-clean-title { color: #e2e8f0; }
body.dark .hero-clean-sub { color: #64748b; }
body.dark .hero-divider { background: linear-gradient(90deg, #60a5fa, transparent); }
body.dark .hero-clean-answer { color: #94a3b8; }
body.dark .hero-clean-answer em { color: #60a5fa; }
body.dark .hero-clean-desc { color: #60a5fa; }
body.dark .hero-clean-btn {
    background: rgba(255,255,255,0.06); color: #e2e8f0;
    border: 1px solid rgba(255,255,255,0.06); box-shadow: none;
}
body.dark .hero-clean-btn:hover {
    background: rgba(255,255,255,0.1); border-color: rgba(255,255,255,0.1);
}

/* Mobile dark sidebar bg */
@media (max-width: 768px) {
    body.dark .tutorial-sidebar { background: #0f172a; }
}