/* ===== 基础变量 ===== */
:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: #161f32;
    --bg-card-hover: #1e2940;
    --bg-featured: #132036;
    --border-color: #243049;
    --border-light: #2d3b55;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --accent-primary: #3b82f6;
    --accent-secondary: #60a5fa;
    --accent-glow: rgba(59, 130, 246, 0.3);
    --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #06b6d4 100%);
    --gold: #fbbf24;
    --success: #22c55e;
    --warning: #f59e0b;
    --danger: #ef4444;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
    --sidebar-width: 280px;
    --topbar-height: 64px;
    --transition: all 0.25s ease;
}

/* Light theme variables */
body.light-theme {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: #ffffff;
    --bg-card-hover: #f1f5f9;
    --bg-featured: #eff6ff;
    --border-color: #e2e8f0;
    --border-light: #cbd5e1;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    --accent-glow: rgba(59, 130, 246, 0.15);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--topbar-height) + 20px);
}

body {
    font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 15px;
    overflow-x: hidden;
}

body.light-theme {
    background-color: var(--bg-primary);
}

/* ===== 布局 ===== */
.app {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    position: fixed;
    top: 0;
    left: 0;
    height: 100vh;
    z-index: 100;
    display: flex;
    flex-direction: column;
    transition: var(--transition);
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-icon {
    font-size: 24px;
}

.logo-text {
    font-weight: 700;
    font-size: 15px;
    color: var(--text-primary);
}

.sidebar-close {
    display: none;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 28px;
    cursor: pointer;
    padding: 0 4px;
}

.toc {
    flex: 1;
    overflow-y: auto;
    padding: 16px 12px;
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.toc-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    text-decoration: none;
    transition: var(--transition);
    font-size: 14px;
}

.toc-link:hover {
    background-color: var(--bg-card-hover);
    color: var(--text-primary);
}

.toc-link.active {
    background-color: var(--bg-card-hover);
    color: var(--accent-secondary);
    font-weight: 500;
}

.toc-link-featured {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.15) 0%, rgba(6, 182, 212, 0.1) 100%);
    border: 1px solid var(--border-light);
}

.toc-link-featured.active {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.25) 0%, rgba(6, 182, 212, 0.15) 100%);
}

.toc-number {
    width: 22px;
    height: 22px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--border-color);
    border-radius: 50%;
    font-size: 12px;
    font-weight: 600;
    flex-shrink: 0;
}

.toc-icon {
    width: 22px;
    text-align: center;
    flex-shrink: 0;
}

.sidebar-footer {
    padding: 16px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-muted);
    font-size: 13px;
}

.main {
    flex: 1;
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.topbar {
    height: var(--topbar-height);
    background-color: rgba(17, 24, 39, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    padding: 0 24px;
    gap: 20px;
}

body.light-theme .topbar {
    background-color: rgba(255, 255, 255, 0.85);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
}

.progress-wrapper {
    flex: 1;
    max-width: 300px;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    color: var(--text-secondary);
}

.progress-bar {
    height: 6px;
    background-color: var(--border-color);
    border-radius: 3px;
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    width: 0%;
    background: var(--accent-gradient);
    border-radius: 3px;
    transition: width 0.4s ease;
    box-shadow: 0 0 10px var(--accent-glow);
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 36px;
    height: 36px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    transition: var(--transition);
}

.theme-toggle:hover {
    background-color: var(--bg-card-hover);
}

.content {
    padding: 40px 32px 60px;
    max-width: 900px;
    width: 100%;
    margin: 0 auto;
}

/* ===== Hero ===== */
.hero {
    text-align: center;
    padding: 60px 20px;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(6, 182, 212, 0.05) 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    margin-bottom: 48px;
    position: relative;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.08) 0%, transparent 70%);
    pointer-events: none;
}

.hero-badge {
    display: inline-block;
    padding: 6px 14px;
    background-color: rgba(59, 130, 246, 0.15);
    border: 1px solid rgba(59, 130, 246, 0.3);
    color: var(--accent-secondary);
    border-radius: 20px;
    font-size: 13px;
    font-weight: 500;
    margin-bottom: 20px;
}

.hero h1 {
    font-size: 42px;
    font-weight: 700;
    margin-bottom: 16px;
    background: linear-gradient(135deg, #fff 0%, #94a3b8 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

body.light-theme .hero h1 {
    background: linear-gradient(135deg, #0f172a 0%, #3b82f6 100%);
    -webkit-background-clip: text;
    background-clip: text;
}

.hero-subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.hero-desc {
    font-size: 15px;
    color: var(--text-muted);
    max-width: 640px;
    margin: 0 auto 28px;
}

.hero-actions {
    display: flex;
    gap: 12px;
    justify-content: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.hero-tip {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 18px;
    background-color: rgba(251, 191, 36, 0.1);
    border: 1px solid rgba(251, 191, 36, 0.25);
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-size: 13px;
    max-width: 600px;
    margin: 0 auto;
}

.tip-icon {
    font-size: 16px;
    flex-shrink: 0;
}

/* ===== 按钮 ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: var(--radius-md);
    font-size: 15px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    border: none;
}

.btn-primary {
    background: var(--accent-gradient);
    color: white;
    box-shadow: 0 4px 16px rgba(59, 130, 246, 0.35);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.45);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-primary);
    border: 1px solid var(--border-light);
}

.btn-secondary:hover {
    background-color: var(--bg-card-hover);
}

/* ===== Section ===== */
.section {
    margin-bottom: 56px;
    scroll-margin-top: calc(var(--topbar-height) + 20px);
}

.section-featured {
    background: linear-gradient(135deg, var(--bg-featured) 0%, rgba(59, 130, 246, 0.05) 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
}

.section-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 24px;
}

.section-number {
    display: inline-block;
    padding: 4px 10px;
    background-color: var(--border-color);
    color: var(--text-secondary);
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    white-space: nowrap;
}

.section-number-featured {
    background: var(--accent-gradient);
    color: white;
}

.section h2 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
}

.section h3 {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin: 32px 0 16px;
}

.section p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.section-intro {
    font-size: 16px;
    margin-bottom: 24px;
}

/* ===== 卡片 ===== */
.card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 24px;
}

.highlight {
    color: var(--accent-secondary);
    font-weight: 500;
}

.compare-box {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 16px;
    align-items: center;
    margin-top: 20px;
}

.compare-item {
    padding: 20px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
}

.compare-item-emphasis {
    border-color: var(--accent-primary);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, transparent 100%);
}

.compare-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.compare-arrow {
    font-size: 24px;
    color: var(--accent-secondary);
    font-weight: 700;
}

/* ===== Feature grid ===== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 20px;
}

.feature-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    transition: var(--transition);
}

.feature-card:hover {
    background-color: var(--bg-card-hover);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 28px;
    margin-bottom: 12px;
}

.feature-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.feature-card p {
    font-size: 13px;
    margin: 0;
    color: var(--text-muted);
}

/* ===== Steps list ===== */
.steps-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.step-item {
    display: flex;
    gap: 16px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
}

.step-marker {
    width: 32px;
    height: 32px;
    background: var(--accent-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 14px;
    flex-shrink: 0;
}

.step-body h3 {
    margin: 0 0 8px;
    font-size: 17px;
}

.step-body p {
    margin: 0;
    color: var(--text-secondary);
}

/* ===== Interface map ===== */
.interface-map {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin: 24px 0;
}

.interface-area {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px;
}

.interface-label {
    display: inline-block;
    padding: 3px 10px;
    background-color: var(--border-color);
    color: var(--text-primary);
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 10px;
}

.interface-area p {
    margin: 0;
    font-size: 14px;
    color: var(--text-secondary);
}

.key-buttons {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-top: 20px;
}

.key-btn-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px;
    text-align: center;
}

.key-btn-label {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.key-btn-item p {
    margin: 0;
    font-size: 13px;
    color: var(--text-muted);
}

/* ===== Formula card ===== */
.formula-card {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(6, 182, 212, 0.05) 100%);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
    margin: 24px 0;
}

.formula-title {
    font-size: 13px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.formula {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    flex-wrap: wrap;
    font-size: 18px;
    font-weight: 600;
}

.formula-part {
    padding: 8px 16px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-sm);
    color: var(--accent-secondary);
}

/* ===== Example prompt ===== */
.example-prompt {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin: 16px 0 24px;
    overflow: hidden;
}

.example-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 16px;
    background-color: rgba(59, 130, 246, 0.08);
    border-bottom: 1px solid var(--border-color);
    font-size: 13px;
    color: var(--text-secondary);
}

.example-content {
    padding: 16px;
    color: var(--text-primary);
    font-family: 'Noto Sans SC', sans-serif;
    font-size: 14px;
    line-height: 1.8;
    white-space: pre-wrap;
}

.copy-btn {
    background: var(--accent-gradient);
    color: white;
    border: none;
    padding: 5px 12px;
    border-radius: var(--radius-sm);
    font-size: 12px;
    cursor: pointer;
    transition: var(--transition);
    font-weight: 500;
}

.copy-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 2px 8px var(--accent-glow);
}

.prompt-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.prompt-group .example-prompt {
    margin: 0;
}

/* ===== Lists ===== */
.numbered-list {
    margin: 16px 0;
    padding-left: 24px;
    color: var(--text-secondary);
}

.numbered-list li {
    margin-bottom: 10px;
}

.check-list {
    list-style: none;
    margin: 16px 0;
    padding: 0;
}

.check-list li {
    padding: 8px 0;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
}

.check-list li:last-child {
    border-bottom: none;
}

/* ===== Result types ===== */
.result-types {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin: 20px 0;
}

.result-type {
    display: flex;
    gap: 14px;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 18px;
}

.result-type-icon {
    font-size: 24px;
}

.result-type-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.result-type p {
    margin: 0;
    font-size: 13px;
    color: var(--text-muted);
}

/* ===== Capability ===== */
.capability {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 16px;
}

.capability h3 {
    margin-top: 0;
    margin-bottom: 12px;
}

.capability p {
    margin-bottom: 12px;
}

.capability .example-prompt {
    margin-bottom: 0;
}

/* ===== Tips grid ===== */
.tips-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 12px;
    margin: 20px 0;
}

.tip-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px;
    text-align: center;
}

.tip-number {
    width: 28px;
    height: 28px;
    background: var(--accent-gradient);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 13px;
    margin: 0 auto 10px;
}

.tip-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    font-size: 14px;
}

.tip-card p {
    margin: 0;
    font-size: 12px;
    color: var(--text-muted);
}

/* ===== Tip box ===== */
.tip-box {
    background-color: rgba(59, 130, 246, 0.08);
    border-left: 3px solid var(--accent-primary);
    border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
    padding: 14px 16px;
    margin-top: 14px;
    font-size: 14px;
    color: var(--text-secondary);
}

.tip-box-important {
    background-color: rgba(239, 68, 68, 0.08);
    border-left-color: var(--danger);
}

/* ===== Exercise ===== */
.exercise {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 22px;
    margin-bottom: 16px;
}

.exercise-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 12px;
}

.exercise-number {
    padding: 3px 10px;
    background: var(--accent-gradient);
    color: white;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 600;
}

.exercise-title {
    font-weight: 600;
    color: var(--text-primary);
}

.exercise > p {
    margin-bottom: 12px;
}

.exercise .example-prompt {
    margin-bottom: 0;
}

/* ===== Amazon module ===== */
.amazon-module {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 24px;
    margin-bottom: 20px;
}

.amazon-module h3 {
    margin-top: 0;
    margin-bottom: 12px;
    font-size: 18px;
}

.amazon-module p {
    margin-bottom: 16px;
}

.workflow-box {
    background-color: var(--bg-secondary);
    border: 1px dashed var(--border-light);
    border-radius: var(--radius-md);
    padding: 18px;
    margin-top: 18px;
}

.workflow-title {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.workflow-box ol {
    padding-left: 20px;
    color: var(--text-secondary);
    font-size: 14px;
}

.workflow-box li {
    margin-bottom: 8px;
}

/* ===== FAQ ===== */
.faq-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.faq-item {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.faq-question {
    padding: 18px 20px;
    font-weight: 600;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition);
}

.faq-question:hover {
    background-color: var(--bg-card-hover);
}

.faq-question::after {
    content: '+';
    font-size: 20px;
    color: var(--accent-secondary);
    transition: var(--transition);
}

.faq-item.active .faq-question::after {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 20px 18px;
    color: var(--text-secondary);
    font-size: 14px;
    display: none;
}

.faq-item.active .faq-answer {
    display: block;
}

/* ===== CTA ===== */
.cta-box {
    background: var(--accent-gradient);
    border-radius: var(--radius-md);
    padding: 32px;
    text-align: center;
    color: white;
    margin-top: 24px;
}

.cta-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 8px;
}

.cta-box p {
    margin: 0;
    opacity: 0.9;
}

/* ===== Footer ===== */
.site-footer {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
    font-size: 13px;
    border-top: 1px solid var(--border-color);
    margin-top: 40px;
}

.site-footer p {
    margin-bottom: 6px;
}

/* ===== Toast ===== */
.toast {
    position: fixed;
    bottom: 30px;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background-color: var(--bg-card);
    color: var(--text-primary);
    padding: 12px 24px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: all 0.3s ease;
    z-index: 200;
    font-size: 14px;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

/* ===== Mobile overlay ===== */
.sidebar-overlay {
    position: fixed;
    inset: 0;
    background-color: rgba(0, 0, 0, 0.6);
    z-index: 99;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

body.light-theme .sidebar-overlay {
    background-color: rgba(0, 0, 0, 0.4);
}

/* ===== 响应式 ===== */
@media (max-width: 1100px) {
    .feature-grid,
    .tips-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 900px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .sidebar-close {
        display: block;
    }

    .main {
        margin-left: 0;
    }

    .menu-toggle {
        display: flex;
    }

    .content {
        padding: 24px 20px 40px;
    }

    .hero h1 {
        font-size: 30px;
    }

    .hero-subtitle {
        font-size: 16px;
    }

    .compare-box,
    .key-buttons,
    .result-types,
    .interface-map {
        grid-template-columns: 1fr;
    }

    .compare-arrow {
        transform: rotate(90deg);
    }

    .tips-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .feature-grid {
        grid-template-columns: 1fr;
    }

    .formula {
        font-size: 15px;
    }
}

@media (max-width: 480px) {
    .tips-grid {
        grid-template-columns: 1fr;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .section-featured {
        padding: 20px;
    }
}

/* ===== 打印优化 ===== */
@media print {
    .sidebar,
    .topbar,
    .hero-actions,
    .copy-btn {
        display: none !important;
    }

    .main {
        margin-left: 0;
    }

    body {
        background: white;
        color: black;
    }

    .section {
        page-break-inside: avoid;
    }
}