/* ============================================
   AstrBot 介绍页 - 主样式表
   设计规范：活力橙 + 大地棕（视觉规范 V1）
   ============================================ */

/* ============================================
   1. CSS 变量定义（:root）
   ============================================ */
:root {
    /* --- 温暖底色 (Warm Citrus Base) --- */
    --color-bg: #fffcf0;
    --color-bg-alt: #fef3c7;
    --color-bg-highlight: #fff7ed;
    --color-surface: #ffffff;

    /* --- 活力品牌色 (Approachable Citrus) --- */
    --color-primary: #f97316;
    --color-primary-soft: #ffedd5;
    --color-primary-hover: #ea580c;
    --color-primary-light: #fdba74;

    /* --- 森林绿色 (Safety & Stability) --- */
    --color-accent: #059669;
    --color-accent-soft: #d1fae5;
    --color-accent-hover: #047857;

    /* --- 大地色文字 (Earthy Typography) --- */
    --color-text: #431407;
    --color-text-muted: #78350f;
    --color-text-dim: #92400e;
    --color-text-light: #b45309;

    /* --- 温润装饰 (Warm Decorations) --- */
    --color-border: #fde68a;
    --color-border-soft: rgba(120, 53, 15, 0.05);
    --color-border-medium: rgba(120, 53, 15, 0.1);

    /* --- 阳光光影 (Sunny Depth) --- */
    --shadow-ambient: 0 10px 15px -3px rgba(120, 53, 15, 0.04),
                      0 4px 6px -2px rgba(120, 53, 15, 0.02);
    --shadow-card: 0 20px 25px -5px rgba(120, 53, 15, 0.06),
                 0 10px 10px -5px rgba(120, 53, 15, 0.03);
    --shadow-hover: 0 25px 50px -12px rgba(120, 53, 15, 0.12),
                 0 12px 24px -8px rgba(120, 53, 15, 0.08);

    /* --- 布局变量 (Friendly Layout) --- */
    --radius-xs: 8px;
    --radius-sm: 16px;
    --radius-card: 32px;
    --radius-button: 999px;
    --radius-pill: 999px;

    /* --- 间距变量 (Spacing) --- */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;
    --spacing-3xl: 6rem;

    /* --- 容器与布局 (Container & Layout) --- */
    --container-max: 1000px;
    --container-wide: 1200px;
    --section-spacing: 140px;
    --section-spacing-mobile: 80px;

    /* --- 字体 (Typography) --- */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
                 "Helvetica Neue", Arial, "Noto Sans", sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
                 "Liberation Mono", monospace;

    /* --- 字号 (Font Size) --- */
    --text-xs: 0.875rem;
    --text-sm: 1rem;
    --text-base: 1.125rem;
    --text-lg: 1.25rem;
    --text-xl: 1.5rem;
    --text-2xl: 1.875rem;
    --text-3xl: 2.25rem;
    --text-4xl: 3rem;
    --text-5xl: 3.75rem;

    /* --- 行高 (Line Height) --- */
    --leading-tight: 1.25;
    --leading-snug: 1.375;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;
    --leading-loose: 1.8;

    /* --- 动画 (Animation) --- */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-bounce: 500ms cubic-bezier(0.175, 0.885, 0.32, 1.275);

    /* --- 断点 (Breakpoints) --- */
    --breakpoint-sm: 640px;
    --breakpoint-md: 768px;
    --breakpoint-lg: 1024px;
    --breakpoint-xl: 1200px;
    --breakpoint-2xl: 1440px;
}

/* --- 深色模式变量（预留） --- */
@media (prefers-color-scheme: dark) {
    :root {
        --color-bg: #1c1917;
        --color-bg-alt: #292524;
        --color-surface: #292524;
        --color-text: #fef3c7;
        --color-text-muted: #fde68a;
        --color-text-dim: #fcd34d;
        --color-border: #451a03;
        --color-border-soft: rgba(253, 230, 138, 0.05);
    }
}

/* ============================================
   2. Reset / Base
   ============================================ */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-loose);
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* 标题 */
h1, h2, h3, h4, h5, h6 {
    color: var(--color-text);
    line-height: var(--leading-snug);
    letter-spacing: -0.03em;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

/* 段落与文本 */
p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-muted);
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-primary-hover);
}

/* 图片 */
img, picture, video, canvas, svg {
    display: block;
    max-width: 100%;
    height: auto;
}

/* 表单元素 */
input, button, textarea, select {
    font: inherit;
    color: inherit;
}

button {
    cursor: pointer;
    background: none;
    border: none;
}

/* 列表 */
ul, ol {
    list-style: none;
}

/* 代码 */
code, pre {
    font-family: var(--font-mono);
    font-size: 0.9em;
}

code {
    background: var(--color-bg-alt);
    padding: 0.2em 0.4em;
    border-radius: var(--radius-xs);
}

pre {
    background: var(--color-surface);
    padding: var(--spacing-md);
    border-radius: var(--radius-card);
    overflow-x: auto;
    border: 2px solid var(--color-border-soft);
}

pre code {
    background: none;
    padding: 0;
}

/* ============================================
   3. Layout
   ============================================ */
/* 页面容器 */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container--wide {
    max-width: var(--container-wide);
}

/* Section */
.section {
    padding: var(--section-spacing-mobile) 0;
}

@media (min-width: 768px) {
    .section {
        padding: var(--section-spacing) 0;
    }
}

.section--alt {
    background-color: var(--color-bg-alt);
}

.section--highlight {
    background-color: var(--color-bg-highlight);
}

/* Grid 系统 */
.grid {
    display: grid;
    gap: var(--spacing-lg);
}

.grid--2 {
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .grid--2 {
        grid-template-columns: repeat(2, 1fr);
    }
}

.grid--3 {
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .grid--3 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid--3 {
        grid-template-columns: repeat(3, 1fr);
    }
}

.grid--4 {
    grid-template-columns: 1fr;
}

@media (min-width: 640px) {
    .grid--4 {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid--4 {
        grid-template-columns: repeat(4, 1fr);
    }
}

/* Flex 工具 */
.flex {
    display: flex;
}

.flex--col {
    flex-direction: column;
}

.flex--center {
    align-items: center;
    justify-content: center;
}

.flex--between {
    align-items: center;
    justify-content: space-between;
}

.flex--gap-sm { gap: var(--spacing-sm); }
.flex--gap-md { gap: var(--spacing-md); }
.flex--gap-lg { gap: var(--spacing-lg); }

/* ============================================
   4. Components
   ============================================ */
/* 卡片 */
.card {
    background: var(--color-surface);
    border: 2px solid var(--color-border-soft);
    border-radius: var(--radius-card);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-card);
    transition: all var(--transition-bounce);
}

.card:hover {
    transform: translateY(-8px) scale(1.02);
    border-color: var(--color-border);
    box-shadow: var(--shadow-hover);
}

.card--sunny {
    background: var(--color-surface);
    border: 2px solid var(--color-border-soft);
}

.card--highlight {
    background: var(--color-bg-highlight);
    border-color: var(--color-border);
}

/* 按钮 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-xs);
    padding: 16px 36px;
    font-size: var(--text-lg);
    font-weight: 700;
    border-radius: var(--radius-button);
    border: none;
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    white-space: nowrap;
}

.btn--primary {
    background: var(--color-primary);
    color: #ffffff;
    box-shadow: 0 8px 15px rgba(249, 115, 22, 0.2);
}

.btn--primary:hover {
    background: var(--color-primary-hover);
    box-shadow: 0 12px 20px rgba(249, 115, 22, 0.3);
    transform: scale(1.05);
}

.btn--secondary {
    background: var(--color-bg-alt);
    color: var(--color-text);
    border: 2px solid var(--color-border);
}

.btn--secondary:hover {
    background: var(--color-bg-highlight);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.btn--accent {
    background: var(--color-accent);
    color: #ffffff;
    box-shadow: 0 8px 15px rgba(5, 150, 105, 0.2);
}

.btn--sm {
    padding: 10px 20px;
    font-size: var(--text-base);
}

.btn--lg {
    padding: 20px 48px;
    font-size: var(--text-xl);
}

/* 标签 */
.tag {
    display: inline-flex;
    align-items: center;
    padding: 8px 18px;
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    font-weight: 600;
    gap: var(--spacing-xs);
}

.tag--primary {
    background: var(--color-primary-soft);
    color: #9a3412;
}

.tag--accent {
    background: var(--color-accent-soft);
    color: #064e3b;
    border: 1px solid rgba(5, 150, 105, 0.1);
}

.tag--outline {
    background: transparent;
    border: 2px solid var(--color-border);
    color: var(--color-text-muted);
}

/* 分隔线 */
.divider {
    height: 2px;
    background: var(--color-border);
    margin: var(--spacing-2xl) 0;
    border-radius: var(--radius-pill);
}

/* 徽章 */
.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 24px;
    height: 24px;
    padding: 0 8px;
    font-size: var(--text-xs);
    font-weight: 700;
    border-radius: var(--radius-pill);
    background: var(--color-primary);
    color: #ffffff;
}

/* ============================================
   5. Utilities
   ============================================ */
/* 间距 */
.mt-xs { margin-top: var(--spacing-xs); }
.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }
.mt-2xl { margin-top: var(--spacing-2xl); }
.mt-3xl { margin-top: var(--spacing-3xl); }

.mb-xs { margin-bottom: var(--spacing-xs); }
.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }
.mb-2xl { margin-bottom: var(--spacing-2xl); }
.mb-3xl { margin-bottom: var(--spacing-3xl); }

.p-xs { padding: var(--spacing-xs); }
.p-sm { padding: var(--spacing-sm); }
.p-md { padding: var(--spacing-md); }
.p-lg { padding: var(--spacing-lg); }
.p-xl { padding: var(--spacing-xl); }
.p-2xl { padding: var(--spacing-2xl); }

/* 文本 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-sm { font-size: var(--text-sm); }
.text-base { font-size: var(--text-base); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }

.text-muted { color: var(--color-text-muted); }
.text-dim { color: var(--color-text-dim); }
.text-primary { color: var(--color-primary); }
.text-accent { color: var(--color-accent); }

/* 显示 */
.hidden { display: none; }

@media (max-width: 767px) {
    .hide-mobile { display: none; }
}

@media (min-width: 768px) {
    .show-mobile { display: none; }
}

/* 可访问性 */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* 交互状态 */
.hover-lift {
    transition: transform var(--transition-bounce);
}

.hover-lift:hover {
    transform: translateY(-8px);
}

/* ============================================
   4. 布局（Layout）
   ============================================ */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 20px;
}

section {
    padding: var(--section-spacing) 0;
}

/* ============================================
   5. 导航（Navigation）
   ============================================ */
.nav-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 2rem;
    background: var(--color-surface);
    box-shadow: var(--shadow-ambient);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-brand a {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
    gap: 2rem;
}

.nav-menu a {
    color: var(--color-text);
    font-weight: 500;
}

.nav-menu a:hover {
    color: var(--color-primary);
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.5rem;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    transition: all 0.3s ease;
}

.lang-switch {
    font-weight: 600;
}

/* ============================================
   6. 页脚（Footer）
   ============================================ */
.footer {
    background-color: var(--color-bg-alt);
    padding: 3rem 0 1rem;
    margin-top: var(--section-spacing);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    font-size: 1.1rem;
    margin-bottom: 1rem;
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--color-text-muted);
}

.footer-section a:hover {
    color: var(--color-primary);
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

.footer-bottom p {
    font-size: 0.9rem;
    margin: 0;
}

/* ============================================
   7. 模块基础样式（Module Base）
   ============================================ */

/* ========================================
   HERO 首屏结论区
   ======================================== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: var(--spacing-3xl) 0;
    overflow: hidden;
}

.hero__content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.hero__title {
    font-size: clamp(var(--text-3xl), 5vw, var(--text-5xl));
    margin-bottom: var(--spacing-xl);
    line-height: var(--leading-snug);
}

.hero__title .highlight {
    color: var(--color-primary);
    position: relative;
    display: inline-block;
}

.hero__title .highlight::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 0;
    right: 0;
    height: 8px;
    background: var(--color-primary-soft);
    border-radius: var(--radius-xs);
    z-index: -1;
}

.hero__description {
    font-size: var(--text-lg);
    line-height: var(--leading-loose);
    margin-bottom: var(--spacing-lg);
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}

.hero__positioning {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    background: var(--color-surface);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--radius-pill);
    border: 2px solid var(--color-border);
    margin-bottom: var(--spacing-lg);
}

.hero__positioning .icon {
    font-size: var(--text-xl);
}

.hero__positioning p {
    margin: 0;
    font-size: var(--text-sm);
    color: var(--color-text);
}

.hero__tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.hero__cta {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-xl);
}

.hero__dev-note {
    background: var(--color-bg-alt);
    border-radius: var(--radius-card);
    padding: var(--spacing-md) var(--spacing-lg);
    border: 2px dashed var(--color-border);
    max-width: 600px;
    margin: 0 auto;
}

.hero__dev-note p {
    margin: 0;
    font-size: var(--text-sm);
}

.hero__dev-note strong {
    color: var(--color-primary);
}

.hero__dev-note a {
    color: var(--color-primary);
    font-weight: 600;
    text-decoration: underline;
    text-underline-offset: 4px;
}

/* Hero 装饰元素 */
.hero__decoration {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    pointer-events: none;
    z-index: 1;
}

.decoration-circle {
    position: absolute;
    border-radius: 50%;
    background: var(--color-primary-soft);
    opacity: 0.5;
    animation: float 6s ease-in-out infinite;
}

.decoration-circle--1 {
    width: 300px;
    height: 300px;
    top: -100px;
    right: -100px;
    animation-delay: 0s;
}

.decoration-circle--2 {
    width: 200px;
    height: 200px;
    bottom: 10%;
    left: -50px;
    animation-delay: 2s;
}

.decoration-circle--3 {
    width: 150px;
    height: 150px;
    top: 30%;
    left: 10%;
    animation-delay: 4s;
}

@keyframes float {
    0%, 100% {
        transform: translateY(0) scale(1);
    }
    50% {
        transform: translateY(-30px) scale(1.05);
    }
}

/* Hero 响应式 */
@media (max-width: 767px) {
    .hero {
        min-height: auto;
        padding: var(--spacing-2xl) 0;
    }

    .hero__title {
        font-size: var(--text-3xl);
    }

    .hero__description {
        font-size: var(--text-base);
    }

    .hero__cta {
        flex-direction: column;
        align-items: stretch;
    }

    .hero__cta .btn {
        width: 100%;
    }

    .decoration-circle {
        display: none;
    }
}

.section-why-astrbot,
.section-capabilities,
.section-developers,
.section-audience,
.section-capabilities-detail,
.section-installation,
.section-use-cases,
.section-comparison,
.section-get-started,
.section-faq,
.section-community {
    /* 各模块特定样式将在 Phase 4 添加 */
}

/* ============================================
   8. 工具类（Utilities）
   ============================================ */
.is-hidden {
    display: none !important;
}

.is-active {
    /* 用于激活状态 */
}

.visually-hidden {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ============================================
   9. 响应式（Responsive）
   ============================================ */
@media (max-width: 767px) {
    /* 移动端导航 */
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 60px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--color-surface);
        padding: 2rem;
        gap: 1rem;
        box-shadow: var(--shadow-card);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all 0.3s ease;
    }

    .nav-menu.is-active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    /* 移动端间距调整 */
    section {
        padding: calc(var(--section-spacing) * 0.6) 0;
    }

    .container {
        padding: 0 16px;
    }
}

@media (min-width: 768px) and (max-width: 1199px) {
    /* 平板端样式 */
}

@media (min-width: 1200px) {
    /* 桌面端样式 */
}

/* ========================================
   COMPARISON GRID - 为什么更适合
   ======================================== */
.section-header {
    text-align: center;
    max-width: 800px;
    margin: 0 auto var(--spacing-3xl);
}

.section-title {
    margin-bottom: var(--spacing-md);
}

.section-subtitle {
    font-size: var(--text-lg);
    color: var(--color-text-muted);
    margin: 0;
}

.comparison-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

@media (min-width: 768px) {
    .comparison-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .comparison-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: var(--spacing-2xl);
    }
}

.comparison-card {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.comparison-card__icon {
    width: 64px;
    height: 64px;
    margin-bottom: var(--spacing-md);
}

.comparison-card__icon svg {
    width: 100%;
    height: 100%;
}

.comparison-card__title {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.comparison-card__description {
    flex: 1;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-md);
}

.comparison-card__platforms {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.platform-tag {
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    background: var(--color-bg-alt);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-text-dim);
    border: 1px solid var(--color-border);
}

.comparison-card__highlight {
    display: flex;
    gap: var(--spacing-xs);
}

.comparison-card__features {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
}

.feature-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background: var(--color-accent-soft);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    font-weight: 600;
    color: var(--color-accent);
}

.feature-item svg {
    flex-shrink: 0;
}

/* ========================================
   CAPABILITIES - 能做什么/不能做什么
   ======================================== */
.capabilities-wrapper {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

@media (min-width: 1024px) {
    .capabilities-wrapper {
        grid-template-columns: 1fr 1fr;
    }
}

.capabilities-section {
    background: var(--color-surface);
    border-radius: var(--radius-card);
    padding: var(--spacing-xl);
    border: 2px solid var(--color-border-soft);
}

.capabilities-section--cannot {
    background: var(--color-bg-highlight);
    border-color: var(--color-border);
}

.capabilities-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.capabilities-icon {
    width: 56px;
    height: 56px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-card);
    flex-shrink: 0;
}

.capabilities-icon--can {
    background: var(--color-accent-soft);
    color: var(--color-accent);
}

.capabilities-icon--cannot {
    background: var(--color-bg-alt);
    color: var(--color-text-dim);
}

.capabilities-header h3 {
    margin: 0;
    font-size: var(--text-2xl);
}

.capabilities-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.capability-item {
    display: flex;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: var(--radius-card);
    background: var(--color-bg);
    border: 2px solid var(--color-border-soft);
    transition: all var(--transition-base);
}

.capability-item:hover {
    border-color: var(--color-border);
}

.capability-item--warning {
    background: #fffbeb;
    border-color: #fde68a;
}

.capability-item__icon {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-pill);
    background: var(--color-accent-soft);
    color: var(--color-accent);
    flex-shrink: 0;
}

.capability-item--warning .capability-item__icon {
    background: #fef3c7;
    color: #92400e;
}

.capability-item__content {
    flex: 1;
}

.capability-item__content h4 {
    font-size: var(--text-base);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.capability-item__content p {
    font-size: var(--text-sm);
    margin: 0;
}

/* ========================================
   INSTALLATION - 安装与部署
   ======================================== */
.installation-tabs {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
    margin-bottom: var(--spacing-2xl);
}

.installation-tab {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-lg);
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-button);
    font-size: var(--text-base);
    font-weight: 600;
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all var(--transition-base);
}

.installation-tab:hover {
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.installation-tab.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #ffffff;
}

.installation-content {
    display: none;
}

.installation-content.active {
    display: block;
}

.installation-path {
    background: var(--color-surface);
    border: 2px solid var(--color-border-soft);
    border-radius: var(--radius-card);
    padding: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

.path-header {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.path-icon {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-card);
    background: var(--color-bg-alt);
    flex-shrink: 0;
}

.path-icon svg {
    width: 32px;
    height: 32px;
}

.path-icon--desktop { color: var(--color-primary); }
.path-icon--docker { color: var(--color-accent); }
.path-icon--panel { color: var(--color-text-dim); }
.path-icon--manual { color: var(--color-text-muted); }
.path-icon--k8s { color: var(--color-primary); }

.path-info {
    flex: 1;
}

.path-info h3 {
    font-size: var(--text-xl);
    margin-bottom: var(--spacing-xs);
}

.path-info p {
    font-size: var(--text-sm);
    margin-bottom: var(--spacing-sm);
}

.path-badges {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.path-steps {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.step {
    display: flex;
    gap: var(--spacing-md);
    align-items: flex-start;
}

.step-number {
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-pill);
    background: var(--color-primary);
    color: #ffffff;
    font-weight: 700;
    flex-shrink: 0;
}

.step-content {
    flex: 1;
}

.step-content h4 {
    font-size: var(--text-base);
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
}

.step-content p {
    font-size: var(--text-sm);
    margin: 0;
}

.path-notice {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--color-bg-highlight);
    border: 2px dashed var(--color-border);
    border-radius: var(--radius-card);
    margin-top: var(--spacing-lg);
}

.path-notice svg {
    flex-shrink: 0;
    color: var(--color-primary);
}

.path-notice p {
    font-size: var(--text-sm);
    margin: 0;
}

.path-notice strong {
    color: var(--color-primary);
}

/* Installation 响应式 */
@media (max-width: 767px) {
    .installation-tabs {
        flex-direction: column;
    }

    .installation-tab {
        width: 100%;
        justify-content: center;
    }
}

/* ========================================
   DEVELOPERS - 写给开发者的 AstrBot
   ======================================== */
.section-developers {
    background: var(--color-bg-alt);
}

.developers-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

/* 开发者卡片 */
.dev-card {
    background: var(--color-surface);
    border-radius: var(--radius-card);
    padding: 2rem;
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
    transition: all var(--transition-bounce);
}

.dev-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-card);
    border-color: var(--color-border);
}

/* 卡片图标 */
.dev-card-icon {
    width: 56px;
    height: 56px;
    background: var(--color-primary-soft);
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    color: var(--color-primary);
}

.dev-card-icon svg {
    width: 28px;
    height: 28px;
}

/* 卡片标题 */
.dev-card-title {
    font-size: var(--text-xl);
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--color-text);
}

/* 卡片描述 */
.dev-card-desc {
    font-size: var(--text-base);
    line-height: var(--leading-relaxed);
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
}

/* 技术标签列表 */
.dev-card-features {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    list-style: none;
    padding: 0;
    margin: 0;
}

.dev-card-features li {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.dev-tag {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--color-accent-soft);
    color: #064e3b;
    border-radius: var(--radius-pill);
    font-weight: 600;
    font-size: var(--text-sm);
    font-family: 'Courier New', monospace;
}

/* 开发者 CTA 区 */
.developers-cta {
    text-align: center;
    padding: 2.5rem;
    background: var(--color-surface);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-ambient);
}

.developers-cta p {
    font-size: var(--text-xl);
    margin-bottom: 1.5rem;
    color: var(--color-text);
}

.cta-group {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.cta-group .btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

/* 开发者模块响应式 */
@media (max-width: 1199px) {
    .developers-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 767px) {
    .developers-grid {
        grid-template-columns: 1fr;
    }

    .section-subtitle {
        font-size: var(--text-base);
    }

    .dev-card {
        padding: 1.5rem;
    }

    .cta-group {
        flex-direction: column;
    }

    .cta-group .btn {
        width: 100%;
    }

    .developers-cta p {
        font-size: var(--text-lg);
    }
}

/* ========================================
   AUDIENCE - 适合谁/不适合谁
   ======================================== */
.section-audience {
    background: var(--color-bg);
}

/* 双列对照布局 */
.audience-comparison {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    gap: 0;
    align-items: start;
}

/* 列容器 */
.audience-column {
    padding: 2rem;
    border-radius: var(--radius-card);
}

.audience-match {
    background: linear-gradient(135deg, var(--color-accent-soft) 0%, rgba(5, 150, 105, 0.05) 100%);
}

.audience-mismatch {
    background: linear-gradient(135deg, var(--color-primary-soft) 0%, rgba(249, 115, 22, 0.05) 100%);
}

/* 列头部 */
.audience-header {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.audience-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.audience-icon-success {
    background: var(--color-accent);
    color: white;
}

.audience-icon-warning {
    background: var(--color-primary);
    color: white;
}

.audience-header h3 {
    font-size: var(--text-xl);
    margin: 0;
}

/* 分割线 */
.audience-divider {
    width: 2px;
    background: linear-gradient(
        to bottom,
        transparent,
        var(--color-border) 20%,
        var(--color-border) 80%,
        transparent
    );
    min-height: 400px;
    align-self: stretch;
}

/* 列表样式 */
.audience-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.audience-item {
    display: flex;
    gap: 1rem;
}

.audience-bullet {
    flex-shrink: 0;
    width: 28px;
    height: 28px;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.audience-match .audience-bullet {
    background: var(--color-accent);
    color: white;
}

.audience-mismatch .audience-bullet {
    background: var(--color-primary);
    color: white;
}

.audience-content {
    flex: 1;
}

.audience-content strong {
    display: block;
    font-size: var(--text-lg);
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.audience-content p {
    font-size: var(--text-sm);
    margin: 0;
    line-height: var(--leading-relaxed);
}

/* 响应式：平板和手机 */
@media (max-width: 991px) {
    .audience-comparison {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto;
        gap: 2rem;
    }

    .audience-divider {
        width: 100%;
        height: 2px;
        min-height: auto;
        grid-row: 2;
        background: linear-gradient(
            to right,
            transparent,
            var(--color-border) 20%,
            var(--color-border) 80%,
            transparent
        );
    }

    .audience-match {
        grid-row: 1;
    }

    .audience-mismatch {
        grid-row: 3;
    }

    .audience-header h3 {
        font-size: var(--text-lg);
    }
}

/* ========================================
   CAPABILITIES DETAIL - 核心能力与典型场景
   ======================================== */
.section-capabilities-detail {
    background: var(--color-bg-alt);
}

/* 分节标题 */
.section-subheading {
    font-size: var(--text-2xl);
    font-weight: 700;
    text-align: center;
    margin: 3rem 0 2rem;
    color: var(--color-text);
    position: relative;
}

.section-subheading::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: var(--color-primary);
    margin: 1rem auto 0;
    border-radius: var(--radius-pill);
}

/* 能力网格 */
.capabilities-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-bottom: 4rem;
}

.capability-item {
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
    transition: all var(--transition-base);
}

.capability-item:hover {
    border-color: var(--color-border);
    box-shadow: var(--shadow-card);
}

.capability-icon {
    width: 48px;
    height: 48px;
    background: var(--color-primary-soft);
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
    margin-bottom: 1rem;
}

.capability-item h4 {
    font-size: var(--text-lg);
    margin-bottom: 0.75rem;
    color: var(--color-text);
}

.capability-item p {
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin: 0;
    color: var(--color-text-muted);
}

/* 场景网格 */
.scenarios-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
}

.scenario-card {
    background: var(--color-surface);
    border-radius: var(--radius-card);
    overflow: hidden;
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
    transition: all var(--transition-base);
}

.scenario-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
}

.scenario-header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-hover) 100%);
    color: white;
    padding: 1.5rem;
    position: relative;
}

.scenario-number {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    font-size: 2.5rem;
    font-weight: 900;
    opacity: 0.3;
    line-height: 1;
}

.scenario-header h4 {
    font-size: var(--text-xl);
    margin: 0;
    color: white;
}

.scenario-body {
    padding: 1.5rem;
}

.scenario-body p {
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin-bottom: 1rem;
    color: var(--color-text-muted);
}

.scenario-features {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.scenario-features li {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    background: var(--color-bg-alt);
    color: var(--color-text-muted);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
}

/* 核心能力与典型场景响应式 */
@media (max-width: 1199px) {
    .capabilities-grid {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 767px) {
    .scenarios-grid {
        grid-template-columns: 1fr;
    }

    .section-subheading {
        font-size: var(--text-xl);
    }

    .capability-item,
    .scenario-body {
        padding: 1.5rem;
    }

    .scenario-header {
        padding: 1.25rem;
    }

    .scenario-number {
        font-size: 2rem;
        top: 1.25rem;
        right: 1.25rem;
    }
}

/* ========================================
   USE CASES - 为什么用作助手底座
   ======================================== */
.section-use-cases {
    background: var(--color-bg);
}

/* 价值链路容器 */
.value-chain {
    display: flex;
    align-items: stretch;
    gap: 1rem;
    margin-bottom: 3rem;
}

/* 价值卡片 */
.value-card {
    flex: 1;
    background: var(--color-surface);
    border-radius: var(--radius-card);
    padding: 2rem;
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
    position: relative;
    transition: all var(--transition-base);
}

.value-card:hover {
    border-color: var(--color-border);
    box-shadow: var(--shadow-card);
}

.value-card-number {
    position: absolute;
    top: -1rem;
    left: 2rem;
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 900;
    font-size: var(--text-xl);
}

.value-card h3 {
    margin: 1rem 0 0.5rem;
    padding-top: 1.5rem;
    font-size: var(--text-xl);
}

.value-card-subtitle {
    color: var(--color-primary);
    font-weight: 600;
    margin-bottom: 1rem;
    font-size: var(--text-sm);
}

.value-card-content p {
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin-bottom: 1rem;
    color: var(--color-text-muted);
}

.value-card-features {
    list-style: none;
    padding: 0;
    margin: 0;
}

.value-card-features li {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    padding: 0.5rem 0;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.check-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 20px;
    height: 20px;
    background: var(--color-accent-soft);
    color: var(--color-accent);
    border-radius: 50%;
    font-size: 0.75rem;
    flex-shrink: 0;
    font-weight: 700;
}

/* 连接箭头 */
.chain-arrow {
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--color-border);
    flex-shrink: 0;
}

/* 底部结论 */
.value-conclusion {
    text-align: center;
    padding: 2rem;
    background: var(--color-accent-soft);
    border-radius: var(--radius-card);
}

.value-conclusion > p {
    font-size: var(--text-lg);
    margin-bottom: 1rem;
    color: var(--color-text);
}

.conclusion-tags {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.conclusion-tag {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    border-radius: var(--radius-pill);
    font-weight: 700;
    font-size: var(--text-base);
}

.conclusion-tag-primary {
    background: var(--color-primary);
    color: white;
}

.conclusion-tag-accent {
    background: var(--color-accent);
    color: white;
}

/* 响应式：平板 */
@media (max-width: 991px) {
    .value-chain {
        flex-direction: column;
    }

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

    .value-card {
        width: 100%;
    }

    .value-conclusion {
        padding: 1.5rem;
    }

    .conclusion-tags {
        flex-direction: column;
        align-items: center;
    }

    .conclusion-tag {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
}

/* ========================================
   COMPARISON - vs OpenClaw
   ======================================== */
.section-comparison {
    background: var(--color-bg-alt);
}

/* 对比维度卡片 */
.comparison-dimensions {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
    margin-bottom: 3rem;
}

.dimension-card {
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
}

.dimension-icon {
    font-size: 2.5rem;
    margin-bottom: 1rem;
}

.dimension-card h3 {
    font-size: var(--text-lg);
    margin-bottom: 1rem;
    color: var(--color-text);
}

.dimension-card p {
    font-size: var(--text-sm);
    line-height: var(--leading-relaxed);
    margin-bottom: 0.75rem;
    color: var(--color-text-muted);
}

.dimension-card strong {
    color: var(--color-primary);
}

/* 对比结论 */
.comparison-conclusion {
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
}

.comparison-conclusion h3 {
    text-align: center;
    font-size: var(--text-xl);
    margin-bottom: 2rem;
}

.conclusion-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.conclusion-item {
    display: flex;
    gap: 1rem;
    align-items: flex-start;
}

.conclusion-badge {
    flex-shrink: 0;
    width: 32px;
    height: 32px;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: var(--text-lg);
}

.conclusion-badge-success {
    background: var(--color-accent);
    color: white;
}

.conclusion-text {
    flex: 1;
}

.conclusion-text strong {
    display: block;
    font-size: var(--text-base);
    margin-bottom: 0.5rem;
    color: var(--color-text);
}

.conclusion-text p {
    font-size: var(--text-sm);
    margin: 0;
    color: var(--color-text-muted);
}

/* 边界说明 */
.comparison-boundary {
    background: var(--color-bg-highlight);
    padding: 1.5rem;
    border-radius: var(--radius-card);
    border: 2px dashed var(--color-border);
}

.comparison-boundary p {
    font-size: var(--text-sm);
    margin-bottom: 0.75rem;
}

.comparison-boundary strong {
    color: var(--color-primary);
}

.comparison-boundary ul {
    margin: 0;
    padding-left: 1.5rem;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.comparison-boundary li {
    margin-bottom: 0.5rem;
}

/* 响应式 */
@media (max-width: 767px) {
    .comparison-dimensions {
        grid-template-columns: 1fr;
    }

    .dimension-card {
        padding: 1.5rem;
    }

    .comparison-conclusion {
        padding: 1.5rem;
    }

    .conclusion-item {
        flex-direction: column;
        text-align: center;
    }
}

/* ========================================
   GET STARTED - 如何开始使用
   ======================================== */
.section-get-started {
    background: var(--color-bg-alt);
}

.steps-container {
    max-width: 800px;
    margin: 0 auto 3rem;
}

.step-item {
    display: flex;
    gap: 2rem;
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-card);
    box-shadow: var(--shadow-ambient);
    margin-bottom: 1rem;
}

.step-number {
    flex-shrink: 0;
    width: 64px;
    height: 64px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--text-3xl);
    font-weight: 900;
}

.step-content h3 {
    margin: 0 0 1rem;
    font-size: var(--text-xl);
}

.step-content p {
    margin-bottom: 1rem;
    color: var(--color-text-muted);
}

.step-options {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.step-options li {
    padding: 0.5rem 1rem;
    background: var(--color-bg-alt);
    border-radius: var(--radius-pill);
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

.step-options li strong {
    color: var(--color-primary);
}

.step-arrow {
    text-align: center;
    font-size: 2rem;
    color: var(--color-border);
    margin: 0.5rem 0;
}

.get-started-cta {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.get-started-cta .btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
}

@media (max-width: 767px) {
    .step-item {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .get-started-cta {
        flex-direction: column;
    }

    .get-started-cta .btn {
        width: 100%;
    }
}

/* ========================================
   FAQ - 常见问题
   ======================================== */
.section-faq {
    background: var(--color-bg);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto 3rem;
}

.faq-item {
    background: var(--color-surface);
    border-radius: var(--radius-card);
    margin-bottom: 1rem;
    box-shadow: var(--shadow-ambient);
    overflow: hidden;
    border: 2px solid var(--color-border-soft);
}

.faq-question-toggle {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    background: none;
    border: none;
    cursor: pointer;
    text-align: left;
    transition: background 0.2s ease;
}

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

.faq-question {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--color-text);
    flex: 1;
}

.faq-icon {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-pill);
    background: var(--color-primary-soft);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    transition: transform 0.3s ease;
}

.faq-question-toggle[aria-expanded="true"] .faq-icon {
    transform: rotate(45deg);
    background: var(--color-primary);
    color: white;
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease-out;
}

.faq-answer.is-expanded {
    max-height: 500px;
}

.faq-answer-content {
    padding: 0 2rem 1.5rem;
}

.faq-answer-content p {
    margin: 0;
    line-height: var(--leading-relaxed);
    color: var(--color-text-muted);
}

.faq-more {
    text-align: center;
}

.faq-more p {
    margin-bottom: 1rem;
    color: var(--color-text-muted);
}

.btn-link {
    display: inline-block;
    color: var(--color-primary);
    font-weight: 600;
    text-decoration: none;
    border-bottom: 2px solid transparent;
    transition: border-color 0.2s ease;
}

.btn-link:hover {
    border-color: var(--color-primary);
}

/* ========================================
   COMMUNITY - 开源与社区
   ======================================== */
.section-community {
    background: var(--color-bg-alt);
}

.opensource-info {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
    margin-bottom: 3rem;
}

.opensource-card {
    background: var(--color-surface);
    padding: 2rem;
    border-radius: var(--radius-card);
    text-align: center;
    box-shadow: var(--shadow-ambient);
    transition: all var(--transition-base);
}

.opensource-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
}

.opensource-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 1rem;
    background: var(--color-primary-soft);
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-primary);
}

.opensource-card h3 {
    margin-bottom: 0.75rem;
    font-size: var(--text-xl);
}

.opensource-card p {
    font-size: var(--text-sm);
    color: var(--color-text-muted);
    margin: 0;
}

.community-links {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.5rem;
}

.community-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: var(--color-surface);
    padding: 1.5rem;
    border-radius: var(--radius-card);
    text-decoration: none;
    box-shadow: var(--shadow-ambient);
    border: 2px solid var(--color-border-soft);
    transition: all 0.3s ease;
}

.community-link:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-card);
    border-color: var(--color-primary);
}

.community-icon {
    width: 56px;
    height: 56px;
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    flex-shrink: 0;
    color: white;
}

.community-icon.github { background: #24292e; }
.community-icon.discord { background: #5865F2; }
.community-icon.docs { background: var(--color-primary); }
.community-icon.plugins { background: var(--color-accent); }

.community-info h4 {
    margin: 0 0 0.25rem;
    color: var(--color-text);
    font-size: var(--text-lg);
}

.community-info p {
    margin: 0;
    font-size: var(--text-sm);
    color: var(--color-text-muted);
}

@media (max-width: 991px) {
    .opensource-info {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 767px) {
    .community-links {
        grid-template-columns: 1fr;
    }
}

/* ========================================
   FOOTER - 页脚完善
   ======================================== */
.footer {
    background: var(--color-bg-alt);
    padding: 4rem 0 2rem;
    margin-top: var(--section-spacing);
    border-top: 3px solid var(--color-border);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-brand {
    grid-column: 1;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--color-primary);
    margin-bottom: 1rem;
}

.footer-tagline {
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
    line-height: var(--leading-relaxed);
}

.footer-social {
    display: flex;
    gap: 1rem;
}

.footer-social a {
    width: 40px;
    height: 40px;
    background: var(--color-surface);
    border-radius: var(--radius-pill);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    transition: all 0.2s ease;
}

.footer-social a:hover {
    background: var(--color-primary);
    color: white;
}

.footer-social svg {
    width: 20px;
    height: 20px;
}

.footer-section h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
    color: var(--color-text);
}

.footer-section ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-section li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: var(--color-text-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-section a:hover {
    color: var(--color-primary);
}

.footer-section a.is-current {
    color: var(--color-primary);
    font-weight: 600;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

.footer-copyright p {
    font-size: 0.9rem;
    color: var(--color-text-dim);
    margin: 0;
}

.footer-legal {
    display: flex;
    gap: 1rem;
    font-size: 0.9rem;
}

.footer-legal span {
    color: var(--color-border);
}

.footer-legal a {
    color: var(--color-text-dim);
    text-decoration: none;
}

.footer-legal a:hover {
    color: var(--color-primary);
}

@media (max-width: 991px) {
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }

    .footer-brand {
        grid-column: 1 / -1;
    }
}

@media (max-width: 767px) {
    .footer {
        padding: 3rem 0 2rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

/* ========================================
   PHASE 5: 交互增强、可访问性与动画样式
   ======================================== */

/* ----------------------------------------
   滚动进入动画
   ---------------------------------------- */

/* 初始状态：隐藏并向下偏移 */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

/* 激活状态：显示并回到原位 */
.animate-on-scroll.is-visible {
    opacity: 1;
    transform: translateY(0);
}

/* 不同方向的动画变体 */
.animate-on-scroll.from-left {
    transform: translateX(-30px);
}

.animate-on-scroll.from-right {
    transform: translateX(30px);
}

.animate-on-scroll.from-left.is-visible,
.animate-on-scroll.from-right.is-visible {
    transform: translateX(0);
}

/* 延迟变体（用于子元素逐个显示） */
.animate-on-scroll.delay-1 { transition-delay: 0.1s; }
.animate-on-scroll.delay-2 { transition-delay: 0.2s; }
.animate-on-scroll.delay-3 { transition-delay: 0.3s; }

/* ----------------------------------------
   导航链接高亮状态
   ---------------------------------------- */

.nav-menu a.is-active {
    color: var(--color-primary);
    font-weight: 600;
}

/* 语言切换当前语言标识 */
.lang-switch.is-current {
    color: var(--color-primary);
    font-weight: 600;
}

/* ----------------------------------------
   焦点可见性样式（可访问性）
   ---------------------------------------- */

/* 焦点样式（键盘导航可见） */
a:focus,
button:focus,
[tabindex]:focus {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

/* 移除鼠标点击时的焦点（可选） */
a:focus:not(:focus-visible),
button:focus:not(:focus-visible) {
    outline: none;
}

/* 仅键盘导航时显示焦点 */
a:focus-visible,
button:focus-visible,
[tabindex]:focus-visible {
    outline: 3px solid var(--color-primary);
    outline-offset: 2px;
}

/* 跳过导航链接（默认隐藏，聚焦时显示） */
.skip-link {
    position: absolute;
    top: -40px;
    left: 0;
    background: var(--color-primary);
    color: white;
    padding: 8px 16px;
    text-decoration: none;
    z-index: 10000;
    border-radius: 0 0 var(--radius-xs) 0;
    font-weight: 600;
}

.skip-link:focus {
    top: 0;
}

/* ----------------------------------------
   FAQ 展开动画（已存在于 FAQ 部分中）
   ---------------------------------------- */

/* .faq-answer 的动画样式已在 FAQ 部分定义 */

/* ----------------------------------------
   尊重用户动画偏好（prefers-reduced-motion）
   ---------------------------------------- */

@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    .animate-on-scroll {
        opacity: 1;
        transform: none;
    }

    .faq-answer {
        transition: none;
    }

    .faq-icon {
        transition: none;
    }
}

/* ----------------------------------------
   平滑滚动（已存在，全局设置）
   ---------------------------------------- */

/* html {
    scroll-behavior: smooth;
} */
/* 已在全局样式或 :root 中定义 */

/* ========================================
   Phase 5 样式结束
   ======================================== */