/* ============================================================
   FFmpeg 官方网站 - 共享样式表
   亮色主题 | 灰绿蓝色系 | 无外部依赖
   ============================================================ */

/* ---------- CSS 变量 ---------- */
:root {
  --bg-page: #F7F6F4;
  --bg-card: #FFFFFF;
  --bg-soft: #EEF2F5;
  --bg-hero: linear-gradient(135deg, #E8F0F5 0%, #F0F5EE 50%, #F5EDE8 100%);

  --c-primary: #5D7FA0;
  --c-primary-dark: #4A6B8A;
  --c-primary-light: #7B9BBA;
  --c-secondary: #7A9F85;
  --c-secondary-dark: #688B74;
  --c-accent: #D4785C;
  --c-accent-dark: #C06848;
  --c-blue-gray: #94A9BC;

  --text-main: #2C3E50;
  --text-body: #4A5568;
  --text-muted: #8896A6;
  --text-light: #A0AEC0;
  --text-white: #FFFFFF;

  --border-color: #E2E8F0;
  --border-hover: #CBD5E0;

  --shadow-sm: 0 1px 3px rgba(44, 62, 80, 0.06);
  --shadow-md: 0 4px 12px rgba(44, 62, 80, 0.08);
  --shadow-lg: 0 8px 28px rgba(44, 62, 80, 0.12);
  --shadow-xl: 0 16px 48px rgba(44, 62, 80, 0.16);

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  --max-width: 1280px;
  --nav-height: 64px;

  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);

  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial,
    sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono",
    "Courier New", Consolas, monospace;
}

/* ---------- 重置 & 基础 ---------- */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background: var(--bg-page);
  color: var(--text-main);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

img, svg {
  display: block;
  max-width: 100%;
}

ul {
  list-style: none;
}

/* ---------- 布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 72px 0;
}

.section-sm {
  padding: 48px 0;
}

.section-title {
  text-align: center;
  margin-bottom: 12px;
  font-size: 2rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.section-title .emoji {
  margin-right: 8px;
}

.section-subtitle {
  text-align: center;
  color: var(--text-muted);
  font-size: 1.05rem;
  margin-bottom: 48px;
  max-width: 640px;
  margin-left: auto;
  margin-right: auto;
}

/* 大屏：三列 / 两列网格 */
.grid {
  display: grid;
  gap: 24px;
}

.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

/* ---------- 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
  transition: var(--transition);
}

.navbar.scrolled {
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  max-width: var(--max-width);
  height: 100%;
  margin: 0 auto;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.35rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.5px;
}

.nav-logo img {
  width: 36px;
  height: 36px;
}

.nav-logo .logo-text {
  background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  color: var(--text-body);
  font-size: 0.95rem;
  font-weight: 600;
  position: relative;
  padding: 4px 0;
}

.nav-links a::after {
  content: "";
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--c-primary);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  width: 100%;
}

.nav-links a.active {
  color: var(--c-primary);
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  background: var(--c-primary);
  color: var(--text-white) !important;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
}

.nav-cta:hover {
  background: var(--c-primary-dark);
  transform: translateY(-1px);
  box-shadow: var(--shadow-md);
}

.nav-cta::after {
  display: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 8px;
  background: none;
  border: none;
}

.nav-toggle span {
  width: 24px;
  height: 2px;
  background: var(--text-main);
  border-radius: 2px;
  transition: var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}
.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}
.nav-toggle.active span:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* ---------- 英雄区 ---------- */
.hero {
  margin-top: var(--nav-height);
  padding: 80px 0 64px;
  background: var(--bg-hero);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -60px;
  right: -60px;
  width: 360px;
  height: 360px;
  background: radial-gradient(circle, rgba(93, 127, 160, 0.08), transparent 70%);
  border-radius: 50%;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -40px;
  left: -40px;
  width: 280px;
  height: 280px;
  background: radial-gradient(circle, rgba(122, 159, 133, 0.08), transparent 70%);
  border-radius: 50%;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 48px;
  position: relative;
  z-index: 1;
}

.hero-content {
  flex: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 16px;
  background: rgba(93, 127, 160, 0.1);
  color: var(--c-primary-dark);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 20px;
}

.hero h1 {
  font-size: 3.2rem;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -1px;
  margin-bottom: 16px;
  color: var(--text-main);
}

.hero h1 .gradient-text {
  background: linear-gradient(135deg, var(--c-primary), var(--c-secondary), var(--c-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero p.hero-desc {
  font-size: 1.15rem;
  color: var(--text-body);
  margin-bottom: 32px;
  max-width: 540px;
}

.hero-buttons {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.hero-meta {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  color: var(--text-muted);
  font-size: 0.88rem;
}

.hero-meta span {
  display: inline-flex;
  align-items: center;
  gap: 6px;
}

.hero-image {
  flex: 0 0 380px;
  text-align: center;
}

.hero-image img {
  width: 100%;
  max-width: 360px;
  margin: 0 auto;
  filter: drop-shadow(0 12px 32px rgba(93, 127, 160, 0.2));
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--c-primary);
  color: var(--text-white);
}

.btn-primary:hover {
  background: var(--c-primary-dark);
  color: var(--text-white);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

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

.btn-secondary:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

/* 夸克网盘按钮 - 蓝紫色系 */
.btn-quark {
  background: linear-gradient(135deg, #4A6CF7, #6B8AFF);
  color: var(--text-white);
}

.btn-quark:hover {
  background: linear-gradient(135deg, #3A5CE5, #5A7AEE);
  color: var(--text-white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(74, 108, 247, 0.35);
}

/* 百度网盘按钮 - 蓝色系 */
.btn-baidu {
  background: linear-gradient(135deg, #06A7FF, #2BB8FF);
  color: var(--text-white);
}

.btn-baidu:hover {
  background: linear-gradient(135deg, #0590DB, #1AA5EE);
  color: var(--text-white);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(6, 167, 255, 0.35);
}

.btn-lg {
  padding: 14px 36px;
  font-size: 1.05rem;
}

.btn-sm {
  padding: 8px 20px;
  font-size: 0.88rem;
}

/* ---------- 统计条 ---------- */
.stats-bar {
  background: var(--bg-card);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  padding: 40px 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  text-align: center;
}

.stat-item .stat-num {
  font-size: 2.4rem;
  font-weight: 800;
  background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -1px;
}

.stat-item .stat-label {
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: 4px;
}

/* ---------- 功能卡片 ---------- */
.feature-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px 28px;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--c-primary), var(--c-secondary));
  transform: scaleX(0);
  transform-origin: left;
  transition: var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-primary-light);
}

.feature-card:hover::before {
  transform: scaleX(1);
}

.feature-icon {
  font-size: 2.2rem;
  margin-bottom: 16px;
  display: inline-block;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-main);
}

.feature-card p {
  color: var(--text-body);
  font-size: 0.95rem;
  line-height: 1.65;
}

/* ---------- 格式标签 ---------- */
.format-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  justify-content: center;
  max-width: 900px;
  margin: 0 auto;
}

.format-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 18px;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-body);
  transition: var(--transition);
  cursor: default;
}

.format-badge:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  transform: translateY(-2px);
  box-shadow: var(--shadow-sm);
}

/* ---------- 截图画廊 ---------- */
.screenshot-gallery {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

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

.screenshot-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--c-primary-light);
}

.screenshot-thumb {
  width: 100%;
  /* 截图缩略图高度限制，避免过大导致卡顿 */
  max-height: 200px;
  overflow: hidden;
  background: var(--bg-soft);
  display: flex;
  align-items: center;
  justify-content: center;
}

.screenshot-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: var(--transition);
}

.screenshot-item:hover .screenshot-thumb img {
  transform: scale(1.03);
}

.screenshot-caption {
  padding: 14px 18px;
}

.screenshot-caption h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 4px;
}

.screenshot-caption p {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ---------- 灯箱 ---------- */
.lightbox {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(44, 62, 80, 0.85);
  z-index: 2000;
  align-items: center;
  justify-content: center;
  padding: 40px;
  cursor: pointer;
}

.lightbox.active {
  display: flex;
  animation: fadeIn 0.3s ease;
}

.lightbox img {
  max-width: 80%;
  max-height: 80vh;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
}

.lightbox-close {
  position: absolute;
  top: 24px;
  right: 32px;
  color: #fff;
  font-size: 2rem;
  cursor: pointer;
  line-height: 1;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ---------- 使用场景卡片 ---------- */
.usecase-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: var(--transition);
}

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

.usecase-card .usecase-emoji {
  font-size: 2rem;
  margin-bottom: 12px;
}

.usecase-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.usecase-card p {
  color: var(--text-body);
  font-size: 0.92rem;
}

/* ---------- 下载区 ---------- */
.download-section {
  background: linear-gradient(135deg, #E8F0F5 0%, #F0F5EE 100%);
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  text-align: center;
}

.download-platforms {
  display: flex;
  justify-content: center;
  gap: 16px;
  margin-bottom: 36px;
  flex-wrap: wrap;
}

.platform-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 20px;
  background: var(--bg-card);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-body);
  cursor: pointer;
  transition: var(--transition);
}

.platform-tag.active,
.platform-tag:hover {
  border-color: var(--c-primary);
  color: var(--c-primary);
  background: rgba(93, 127, 160, 0.05);
}

.download-buttons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.download-info {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin-top: 16px;
}

.download-info code {
  background: var(--bg-soft);
  padding: 2px 8px;
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--c-accent-dark);
}

/* ---------- FAQ 手风琴 ---------- */
.faq-list {
  max-width: 760px;
  margin: 0 auto;
}

.faq-item {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
  transition: var(--transition);
}

.faq-item.active {
  border-color: var(--c-primary-light);
  box-shadow: var(--shadow-md);
}

.faq-question {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  cursor: pointer;
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-main);
  user-select: none;
}

.faq-question .faq-icon {
  font-size: 1.2rem;
  transition: var(--transition);
  color: var(--c-primary);
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease, padding 0.35s ease;
  padding: 0 24px;
  color: var(--text-body);
  font-size: 0.92rem;
  line-height: 1.7;
}

.faq-item.active .faq-answer {
  max-height: 300px;
  padding: 0 24px 18px;
}

/* ---------- 新闻/更新 ---------- */
.news-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 24px;
  transition: var(--transition);
  border-left: 4px solid var(--c-primary);
}

.news-card:hover {
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.news-date {
  display: inline-block;
  font-size: 0.8rem;
  color: var(--c-primary);
  font-weight: 600;
  margin-bottom: 8px;
}

.news-card h4 {
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.news-card p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

/* ---------- 命令行展示 ---------- */
.code-block {
  background: #1E2A3A;
  border-radius: var(--radius-md);
  padding: 24px 28px;
  font-family: var(--font-mono);
  font-size: 0.88rem;
  line-height: 1.8;
  overflow-x: auto;
  box-shadow: var(--shadow-md);
}

.code-block .code-comment { color: #6B8298; }
.code-block .code-cmd { color: #7A9F85; font-weight: 600; }
.code-block .code-flag { color: #D4785C; }
.code-block .code-val { color: #94A9BC; }
.code-block .code-output { color: #A0AEC0; }

/* ---------- 时间线 ---------- */
.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
  padding-left: 32px;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--c-primary), var(--c-secondary), var(--c-accent));
}

.timeline-item {
  position: relative;
  margin-bottom: 36px;
  padding-left: 28px;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 4px;
  width: 14px;
  height: 14px;
  background: var(--bg-card);
  border: 3px solid var(--c-primary);
  border-radius: 50%;
}

.timeline-year {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--c-primary);
  margin-bottom: 4px;
}

.timeline-item h4 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 6px;
}

.timeline-item p {
  color: var(--text-body);
  font-size: 0.92rem;
}

/* ---------- 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
}

table {
  width: 100%;
  border-collapse: collapse;
  background: var(--bg-card);
}

th, td {
  padding: 14px 20px;
  text-align: left;
  border-bottom: 1px solid var(--border-color);
}

th {
  background: var(--bg-soft);
  font-weight: 700;
  color: var(--text-main);
  font-size: 0.9rem;
}

td {
  color: var(--text-body);
  font-size: 0.9rem;
}

tr:last-child td {
  border-bottom: none;
}

tr:hover td {
  background: rgba(93, 127, 160, 0.03);
}

/* ---------- 信息卡片 ---------- */
.info-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 32px;
  transition: var(--transition);
}

.info-card:hover {
  box-shadow: var(--shadow-md);
}

.info-card h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 12px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.info-card p {
  color: var(--text-body);
  margin-bottom: 12px;
}

.info-card ul {
  padding-left: 0;
}

.info-card ul li {
  padding: 6px 0;
  color: var(--text-body);
  display: flex;
  align-items: flex-start;
  gap: 8px;
}

.info-card ul li::before {
  content: "✓";
  color: var(--c-secondary);
  font-weight: 700;
  flex-shrink: 0;
}

/* ---------- CTA 横幅 ---------- */
.cta-banner {
  background: linear-gradient(135deg, var(--c-primary), var(--c-secondary));
  border-radius: var(--radius-xl);
  padding: 56px 48px;
  text-align: center;
  color: var(--text-white);
  position: relative;
  overflow: hidden;
}

.cta-banner::before {
  content: "🎬";
  position: absolute;
  top: -20px;
  right: -10px;
  font-size: 12rem;
  opacity: 0.08;
}

.cta-banner h2 {
  font-size: 2rem;
  font-weight: 800;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.cta-banner p {
  font-size: 1.05rem;
  opacity: 0.9;
  margin-bottom: 28px;
  position: relative;
  z-index: 1;
}

.cta-banner .btn {
  background: var(--text-white);
  color: var(--c-primary-dark);
  position: relative;
  z-index: 1;
}

.cta-banner .btn:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-xl);
}

/* ---------- 页脚 ---------- */
.footer {
  background: #2C3E50;
  color: #A0AEC0;
  padding: 64px 0 24px;
  margin-top: 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 40px;
  margin-bottom: 40px;
}

.footer-brand .footer-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 800;
  color: #fff;
  margin-bottom: 12px;
}

.footer-brand .footer-logo img {
  width: 32px;
  height: 32px;
}

.footer-brand p {
  font-size: 0.88rem;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  color: #fff;
  font-size: 0.95rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.footer-col ul li {
  margin-bottom: 10px;
}

.footer-col ul li a {
  color: #A0AEC0;
  font-size: 0.88rem;
}

.footer-col ul li a:hover {
  color: #fff;
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 24px;
  text-align: center;
  font-size: 0.82rem;
  color: #718096;
}

.footer-bottom .footer-links {
  display: flex;
  justify-content: center;
  gap: 20px;
  margin-bottom: 12px;
}

.footer-bottom .footer-links a {
  color: #A0AEC0;
  font-size: 0.82rem;
}

/* ---------- 页面头部（内页） ---------- */
.page-header {
  margin-top: var(--nav-height);
  padding: 64px 0 48px;
  background: var(--bg-hero);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: "";
  position: absolute;
  top: -40px;
  right: -40px;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(93, 127, 160, 0.08), transparent 70%);
  border-radius: 50%;
}

.page-header h1 {
  font-size: 2.6rem;
  font-weight: 800;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.page-header p {
  color: var(--text-body);
  font-size: 1.1rem;
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 24px;
}

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

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

.breadcrumb .separator {
  color: var(--text-light);
}

/* ---------- 标签页 ---------- */
.tabs {
  display: flex;
  gap: 8px;
  margin-bottom: 32px;
  border-bottom: 2px solid var(--border-color);
  flex-wrap: wrap;
}

.tab-btn {
  padding: 12px 24px;
  background: none;
  border: none;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--text-muted);
  cursor: pointer;
  border-bottom: 3px solid transparent;
  margin-bottom: -2px;
  transition: var(--transition);
}

.tab-btn:hover {
  color: var(--c-primary);
}

.tab-btn.active {
  color: var(--c-primary);
  border-bottom-color: var(--c-primary);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
  animation: fadeInUp 0.4s ease;
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- 滚动动画 ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   响应式 - 移动端 (<768px)
   ============================================================ */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--bg-card);
    flex-direction: column;
    align-items: flex-start;
    padding: 24px;
    gap: 16px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: var(--transition);
  }

  .nav-links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav-toggle {
    display: flex;
  }

  .hero {
    padding: 48px 0 40px;
  }

  .hero-inner {
    flex-direction: column-reverse;
    text-align: center;
    gap: 32px;
  }

  .hero-image {
    flex: 0 0 auto;
  }

  .hero-image img {
    max-width: 200px;
  }

  .hero h1 {
    font-size: 2rem;
  }

  .hero p.hero-desc {
    font-size: 1rem;
    margin: 0 auto 24px;
  }

  .hero-buttons {
    justify-content: center;
  }

  .hero-meta {
    justify-content: center;
  }

  .section {
    padding: 48px 0;
  }

  .section-title {
    font-size: 1.5rem;
  }

  .grid-2,
  .grid-3,
  .grid-4 {
    grid-template-columns: 1fr;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .stat-item .stat-num {
    font-size: 1.8rem;
  }

  .screenshot-gallery {
    grid-template-columns: 1fr;
  }

  .download-section {
    padding: 36px 20px;
  }

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

  .download-buttons .btn {
    justify-content: center;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 24px;
  }

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

  .page-header h1 {
    font-size: 1.8rem;
  }

  .cta-banner {
    padding: 36px 24px;
  }

  .cta-banner h2 {
    font-size: 1.5rem;
  }
}

/* ============================================================
   响应式 - 平板 (769px ~ 1024px)
   ============================================================ */
@media (max-width: 1024px) and (min-width: 769px) {
  .grid-4 {
    grid-template-columns: repeat(2, 1fr);
  }

  .grid-3 {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero h1 {
    font-size: 2.6rem;
  }

  .hero-image {
    flex: 0 0 300px;
  }
}

/* ============================================================
   响应式 - 超大屏 (>1280px)
   ============================================================ */
@media (min-width: 1281px) {
  .hero h1 {
    font-size: 3.6rem;
  }
}