/* ============================================
   IDM 下载官网 - 全站统一样式表
   设计风格:深蓝科技 + 活力橙强调 + 玻璃态质感
   ============================================ */

/* ---------- CSS 变量(设计令牌) ---------- */
:root {
  /* 主色调 */
  --color-primary: #0A2540;
  --color-primary-dark: #061A2E;
  --color-primary-light: #1E3A5F;
  --color-accent: #1E88E5;
  --color-accent-light: #4FC3F7;
  --color-accent-dark: #1565C0;
  --color-orange: #FF6B35;
  --color-orange-light: #FF8A5C;
  --color-orange-dark: #E55300;

  /* 辅助色 */
  --color-bg: #F8FAFC;
  --color-bg-alt: #F1F5F9;
  --color-bg-dark: #0A2540;
  --color-surface: #FFFFFF;
  --color-surface-alt: #F8FAFC;
  --color-border: #E2E8F0;
  --color-border-dark: #2C3E50;

  /* 文字色 */
  --color-text: #1A202C;
  --color-text-secondary: #4A5568;
  --color-text-muted: #718096;
  --color-text-light: #A0AEC0;
  --color-text-inverse: #FFFFFF;

  /* 状态色 */
  --color-success: #10B981;
  --color-warning: #F59E0B;
  --color-danger: #EF4444;

  /* 字体 */
  --font-sans: 'Noto Sans SC', 'HarmonyOS Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'Consolas', 'Monaco', monospace;
  --font-display: 'Noto Sans SC', 'PingFang SC', system-ui, sans-serif;

  /* 字号 */
  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-lg: 1.125rem;
  --fs-xl: 1.25rem;
  --fs-2xl: 1.5rem;
  --fs-3xl: 1.875rem;
  --fs-4xl: 2.25rem;
  --fs-5xl: 3rem;
  --fs-6xl: 3.75rem;

  /* 间距 */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-2xl: 24px;
  --radius-full: 9999px;

  /* 阴影 */
  --shadow-sm: 0 1px 2px 0 rgba(10, 37, 64, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(10, 37, 64, 0.08), 0 2px 4px -1px rgba(10, 37, 64, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(10, 37, 64, 0.1), 0 4px 6px -2px rgba(10, 37, 64, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(10, 37, 64, 0.12), 0 10px 10px -5px rgba(10, 37, 64, 0.04);
  --shadow-2xl: 0 25px 50px -12px rgba(10, 37, 64, 0.25);
  --shadow-glow: 0 0 40px rgba(30, 136, 229, 0.3);

  /* 渐变 */
  --gradient-primary: linear-gradient(135deg, #0A2540 0%, #1E88E5 100%);
  --gradient-accent: linear-gradient(135deg, #1E88E5 0%, #4FC3F7 100%);
  --gradient-orange: linear-gradient(135deg, #FF6B35 0%, #FF8A5C 100%);
  --gradient-hero: linear-gradient(135deg, #061A2E 0%, #0A2540 50%, #1E3A5F 100%);

  /* 过渡 */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);

  /* 容器宽度 */
  --container-max: 1200px;
  --container-narrow: 800px;
}

/* ---------- 全局重置 ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

ul, ol {
  list-style: none;
}

/* ---------- 容器 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-6);
}

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

/* ---------- 排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2rem, 5vw, var(--fs-6xl)); }
h2 { font-size: clamp(1.5rem, 3vw, var(--fs-4xl)); }
h3 { font-size: clamp(1.25rem, 2vw, var(--fs-2xl)); }
h4 { font-size: var(--fs-xl); }

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

.text-gradient {
  background: var(--gradient-accent);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  color: transparent;
}

.text-orange {
  color: var(--color-orange);
}

.text-center { text-align: center; }
.text-mono { font-family: var(--font-mono); }

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.6);
  transition: all var(--transition-base);
}

.site-header.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-md);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-xl);
  color: var(--color-primary);
  text-decoration: none;
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient-primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: var(--fs-base);
  box-shadow: var(--shadow-md);
  position: relative;
  overflow: hidden;
}

.logo-icon::after {
  content: '';
  position: absolute;
  top: 0; left: -100%;
  width: 100%; height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.4), transparent);
  animation: logo-shine 3s ease-in-out infinite;
}

@keyframes logo-shine {
  0%, 100% { left: -100%; }
  50% { left: 100%; }
}

.logo-text {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
}

.nav-menu a {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  position: relative;
  padding: var(--space-2) 0;
  transition: color var(--transition-fast);
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-accent);
  transition: all var(--transition-base);
  transform: translateX(-50%);
}

.nav-menu a:hover,
.nav-menu a.active {
  color: var(--color-accent);
}

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

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  background: var(--gradient-orange);
  color: white;
  font-weight: 600;
  font-size: var(--fs-sm);
  border-radius: var(--radius-full);
  box-shadow: 0 4px 14px rgba(255, 107, 53, 0.35), 0 0 0 0 rgba(255, 107, 53, 0.5);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  isolation: isolate;
}

/* 按钮内部下载图标 */
.nav-cta::before {
  content: '';
  position: relative;
  width: 16px;
  height: 16px;
  flex-shrink: 0;
  background-color: currentColor;
  -webkit-mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M19 9h-4V3H9v6H5l7 7 7-7zM5 18v2h14v-2H5z'/></svg>") center/contain no-repeat;
  mask: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'><path d='M19 9h-4V3H9v6H5l7 7 7-7zM5 18v2h14v-2H5z'/></svg>") center/contain no-repeat;
}

/* 光泽扫过效果 */
.nav-cta::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, transparent 30%, rgba(255, 255, 255, 0.35) 50%, transparent 70%);
  transform: translateX(-100%);
  transition: transform 0.6s ease;
  z-index: -1;
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 24px rgba(255, 107, 53, 0.5), 0 0 0 4px rgba(255, 107, 53, 0.12);
  color: white;
}

.nav-cta:hover::after {
  transform: translateX(100%);
}

/* 持续脉动光晕(吸引注意力) */
@keyframes nav-cta-pulse {
  0%, 100% {
    box-shadow: 0 4px 14px rgba(255, 107, 53, 0.35), 0 0 0 0 rgba(255, 107, 53, 0.45);
  }
  50% {
    box-shadow: 0 4px 14px rgba(255, 107, 53, 0.35), 0 0 0 8px rgba(255, 107, 53, 0);
  }
}

.nav-cta {
  animation: nav-cta-pulse 2.4s ease-in-out infinite;
}

.nav-cta:hover,
.nav-cta:focus-visible {
  animation: none;
}

.menu-toggle {
  display: none;
  width: 40px;
  height: 40px;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 5px;
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}

.menu-toggle span {
  width: 22px;
  height: 2px;
  background: var(--color-primary);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.menu-toggle.active span:nth-child(2) {
  opacity: 0;
}
.menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-4) var(--space-8);
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  font-weight: 600;
  border-radius: var(--radius-full);
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  white-space: nowrap;
  text-decoration: none;
  border: 2px solid transparent;
}

.btn::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
  width: 400px;
  height: 400px;
}

.btn-primary {
  background: var(--gradient-orange);
  color: white;
  box-shadow: 0 8px 20px rgba(255, 107, 53, 0.35);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px rgba(255, 107, 53, 0.45);
  color: white;
}

.btn-secondary {
  background: var(--gradient-accent);
  color: white;
  box-shadow: 0 8px 20px rgba(30, 136, 229, 0.35);
}

.btn-secondary:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 28px rgba(30, 136, 229, 0.45);
  color: white;
}

.btn-outline {
  background: transparent;
  color: var(--color-primary);
  border-color: var(--color-border);
}

.btn-outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateY(-2px);
}

.btn-lg {
  padding: var(--space-5) var(--space-12);
  font-size: var(--fs-lg);
}

.btn-icon {
  width: 20px;
  height: 20px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

/* ---------- Hero 区 ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  padding: calc(72px + var(--space-16)) 0 var(--space-24);
  background: var(--gradient-hero);
  overflow: hidden;
  color: white;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 30%, rgba(30, 136, 229, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 80% 70%, rgba(255, 107, 53, 0.2) 0%, transparent 50%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255,255,255,0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.03) 1px, transparent 1px);
  background-size: 50px 50px;
  pointer-events: none;
  mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
  -webkit-mask-image: radial-gradient(ellipse at center, black 0%, transparent 70%);
}

.hero-shapes {
  position: absolute;
  inset: 0;
  overflow: hidden;
  pointer-events: none;
}

.hero-shape {
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.4;
  animation: float 20s ease-in-out infinite;
}

.shape-1 {
  width: 300px;
  height: 300px;
  background: var(--color-accent);
  top: 10%;
  left: 5%;
  animation-delay: 0s;
}

.shape-2 {
  width: 400px;
  height: 400px;
  background: var(--color-orange);
  top: 40%;
  right: 5%;
  animation-delay: -5s;
}

.shape-3 {
  width: 250px;
  height: 250px;
  background: var(--color-accent-light);
  bottom: 10%;
  left: 30%;
  animation-delay: -10s;
}

@keyframes float {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -30px) scale(1.1); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero-content {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: var(--space-12);
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  margin-bottom: var(--space-6);
  animation: fadeUp 0.8s ease 0s both;
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: var(--color-success);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6); }
  50% { opacity: 0.7; box-shadow: 0 0 0 8px rgba(16, 185, 129, 0); }
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4.5rem);
  font-weight: 800;
  line-height: 1.1;
  color: white;
  margin-bottom: var(--space-6);
  animation: fadeUp 0.8s ease 0.15s both;
}

.hero-title .highlight {
  background: linear-gradient(135deg, #FF6B35 0%, #FFB088 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  position: relative;
  display: inline-block;
}

.hero-subtitle {
  font-size: var(--fs-lg);
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-8);
  max-width: 540px;
  line-height: 1.7;
  animation: fadeUp 0.8s ease 0.3s both;
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-6);
  animation: fadeUp 0.8s ease 0.45s both;
}

/* Hero 卖点徽章(汉化版/绿色版/不限速等) */
.hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-10);
  animation: fadeUp 0.8s ease 0.5s both;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-full);
  font-size: var(--fs-sm);
  color: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(10px);
  transition: all var(--transition-base);
}

.hero-tag:hover {
  background: rgba(255, 107, 53, 0.15);
  border-color: rgba(255, 107, 53, 0.4);
  transform: translateY(-2px);
}

.hero-tag::before {
  content: '✓';
  color: var(--color-orange);
  font-weight: 700;
  font-size: var(--fs-xs);
}

.hero-stats {
  display: flex;
  gap: var(--space-8);
  animation: fadeUp 0.8s ease 0.6s both;
}

.stat {
  display: flex;
  flex-direction: column;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: var(--fs-3xl);
  font-weight: 700;
  color: white;
  line-height: 1;
}

.stat-label {
  font-size: var(--fs-xs);
  color: rgba(255, 255, 255, 0.6);
  margin-top: var(--space-1);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Hero 截图卡片 */
.hero-visual {
  position: relative;
  animation: fadeUp 1s ease 0.5s both;
}

.hero-screenshot {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: 0 30px 80px rgba(0, 0, 0, 0.4);
  background: var(--color-primary-dark);
  border: 1px solid rgba(255, 255, 255, 0.1);
}

.hero-screenshot::before {
  content: '';
  position: absolute;
  inset: -2px;
  background: linear-gradient(135deg, rgba(30, 136, 229, 0.5), rgba(255, 107, 53, 0.5));
  border-radius: var(--radius-xl);
  z-index: -1;
  filter: blur(20px);
  opacity: 0.6;
}

.hero-screenshot img {
  width: 100%;
  height: auto;
  display: block;
}

.hero-window-controls {
  position: absolute;
  top: var(--space-4);
  left: var(--space-4);
  display: flex;
  gap: var(--space-2);
  z-index: 2;
}

.window-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
}

.window-dot.red { background: #FF5F57; }
.window-dot.yellow { background: #FEBC2E; }
.window-dot.green { background: #28C840; }

.hero-floating-badge {
  position: absolute;
  background: white;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-primary);
  animation: float 4s ease-in-out infinite;
}

.hero-floating-badge.top-right {
  top: -20px;
  right: -20px;
}

.hero-floating-badge.bottom-left {
  bottom: -20px;
  left: -20px;
  animation-delay: -2s;
}

.badge-icon {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
}

.badge-icon.orange {
  background: var(--gradient-orange);
}

/* ---------- 区块通用 ---------- */
.section {
  padding: var(--space-24) 0;
}

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

.section-dark {
  background: var(--color-primary);
  color: white;
}

.section-header {
  text-align: center;
  max-width: 720px;
  margin: 0 auto var(--space-16);
}

.section-eyebrow {
  display: inline-block;
  font-size: var(--fs-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: var(--space-3);
  padding: var(--space-1) var(--space-4);
  background: rgba(30, 136, 229, 0.1);
  border-radius: var(--radius-full);
}

.section-title {
  font-size: clamp(2rem, 4vw, var(--fs-5xl));
  font-weight: 800;
  margin-bottom: var(--space-4);
  color: var(--color-text);
}

.section-dark .section-title {
  color: white;
}

.section-subtitle {
  font-size: var(--fs-lg);
  color: var(--color-text-secondary);
  line-height: 1.7;
}

.section-dark .section-subtitle {
  color: rgba(255, 255, 255, 0.75);
}

/* ---------- 卡片网格 ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  align-items: stretch;
}

@media (max-width: 1024px) {
  .features-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 600px) {
  .features-grid {
    grid-template-columns: 1fr;
  }
}

.feature-card {
  background: var(--color-surface);
  padding: var(--space-8);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  height: 100%;
}

/* 让卡片标题与正文高度统一,确保 8 个方块底部对齐 */
.feature-card .feature-icon {
  margin-bottom: var(--space-5);
}

.feature-card .feature-title {
  margin-bottom: var(--space-3);
  min-height: 1.6em;
}

.feature-card .feature-desc {
  flex: 1;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 4px;
  background: var(--gradient-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

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

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

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  margin-bottom: var(--space-5);
  transition: transform var(--transition-base);
}

.feature-card:hover .feature-icon {
  transform: scale(1.1) rotate(-5deg);
}

.feature-icon.orange {
  background: var(--gradient-orange);
}

.feature-icon.green {
  background: linear-gradient(135deg, #10B981 0%, #34D399 100%);
}

.feature-icon.purple {
  background: linear-gradient(135deg, #8B5CF6 0%, #A78BFA 100%);
}

.feature-title {
  font-size: var(--fs-xl);
  font-weight: 700;
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

.feature-desc {
  color: var(--color-text-secondary);
  font-size: var(--fs-base);
  line-height: 1.7;
  margin: 0;
}

/* ---------- 截图展示 ---------- */
.screenshot-showcase {
  position: relative;
  padding: var(--space-16) 0;
}

.screenshot-frame {
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
  border-radius: var(--radius-2xl);
  overflow: hidden;
  box-shadow: var(--shadow-2xl);
  background: var(--color-primary-dark);
  border: 1px solid var(--color-border);
}

.screenshot-frame::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 40px;
  background: linear-gradient(180deg, #1E293B 0%, #0F172A 100%);
  border-bottom: 1px solid rgba(255, 255, 255, 0.05);
  z-index: 1;
}

.screenshot-frame::after {
  content: '';
  position: absolute;
  top: 16px;
  left: 16px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #FF5F57;
  box-shadow: 20px 0 0 #FEBC2E, 40px 0 0 #28C840;
  z-index: 2;
}

.screenshot-frame img {
  display: block;
  width: 100%;
  height: auto;
  margin-top: 40px;
}

.screenshot-glow {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 120%;
  height: 120%;
  background: radial-gradient(ellipse at center, rgba(30, 136, 229, 0.3) 0%, transparent 60%);
  filter: blur(40px);
  z-index: -1;
  pointer-events: none;
}

/* ---------- 版本特性 ---------- */
.version-card {
  background: var(--gradient-primary);
  border-radius: var(--radius-2xl);
  padding: var(--space-12);
  color: white;
  position: relative;
  overflow: hidden;
}

.version-card::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -10%;
  width: 400px;
  height: 400px;
  background: radial-gradient(circle, rgba(255, 107, 53, 0.3) 0%, transparent 70%);
  border-radius: 50%;
}

.version-content {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.version-info .version-label {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  background: rgba(255, 107, 53, 0.2);
  border: 1px solid rgba(255, 107, 53, 0.4);
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 600;
  color: #FFB088;
  margin-bottom: var(--space-3);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.version-number {
  font-family: var(--font-mono);
  font-size: var(--fs-6xl);
  font-weight: 800;
  line-height: 1;
  background: linear-gradient(135deg, #FFFFFF 0%, #B0DDFF 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-4);
}

.version-date {
  color: rgba(255, 255, 255, 0.7);
  font-size: var(--fs-base);
}

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

.version-features li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  color: rgba(255, 255, 255, 0.9);
  font-size: var(--fs-base);
}

.version-features li:last-child {
  border-bottom: none;
}

.version-features li::before {
  content: '✓';
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  background: var(--gradient-orange);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: var(--fs-xs);
  font-weight: 700;
  margin-top: 2px;
}

/* ---------- 用户评价 ---------- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-6);
}

.testimonial-card {
  background: var(--color-surface);
  padding: var(--space-8);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  position: relative;
  transition: all var(--transition-base);
}

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

.testimonial-quote {
  font-size: 80px;
  line-height: 1;
  color: var(--color-accent);
  opacity: 0.15;
  font-family: Georgia, serif;
  position: absolute;
  top: var(--space-4);
  right: var(--space-6);
}

.testimonial-rating {
  display: flex;
  gap: 2px;
  margin-bottom: var(--space-4);
  color: #FBBF24;
}

.testimonial-text {
  font-size: var(--fs-base);
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: var(--space-6);
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.author-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 700;
  font-size: var(--fs-base);
}

.author-info {
  display: flex;
  flex-direction: column;
}

.author-name {
  font-weight: 600;
  color: var(--color-text);
  font-size: var(--fs-sm);
}

.author-role {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

/* ---------- CTA 区块 ---------- */
.cta-section {
  background: var(--gradient-hero);
  position: relative;
  overflow: hidden;
  color: white;
  padding: var(--space-24) 0;
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 30% 50%, rgba(255, 107, 53, 0.2) 0%, transparent 50%),
    radial-gradient(circle at 70% 50%, rgba(30, 136, 229, 0.2) 0%, transparent 50%);
}

.cta-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}

.cta-title {
  font-size: clamp(2rem, 4vw, var(--fs-5xl));
  font-weight: 800;
  margin-bottom: var(--space-4);
  color: white;
}

.cta-subtitle {
  font-size: var(--fs-lg);
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-8);
}

.cta-actions {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  flex-wrap: wrap;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--color-primary-dark);
  color: rgba(255, 255, 255, 0.7);
  padding: var(--space-20) 0 var(--space-8);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
  margin-bottom: var(--space-12);
}

.footer-brand .logo {
  color: white;
  margin-bottom: var(--space-4);
}

.footer-brand p {
  font-size: var(--fs-sm);
  color: rgba(255, 255, 255, 0.6);
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h4 {
  color: white;
  font-size: var(--fs-sm);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-4);
}

.footer-col ul li {
  margin-bottom: var(--space-3);
}

.footer-col ul li a {
  color: rgba(255, 255, 255, 0.6);
  font-size: var(--fs-sm);
  transition: color var(--transition-fast);
}

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

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-8);
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  font-size: var(--fs-sm);
  color: rgba(255, 255, 255, 0.5);
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-social {
  display: flex;
  gap: var(--space-3);
}

.social-link {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  display: flex;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.7);
  transition: all var(--transition-base);
}

.social-link:hover {
  background: var(--gradient-accent);
  color: white;
  transform: translateY(-2px);
}

/* ---------- 面包屑 ---------- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-4) 0;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-top: 72px;
}

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

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

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

.breadcrumb-current {
  color: var(--color-text);
  font-weight: 500;
}

/* ---------- 页面通用标题区 ---------- */
.page-hero {
  background: var(--gradient-hero);
  color: white;
  padding: calc(72px + var(--space-16)) 0 var(--space-20);
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    radial-gradient(circle at 20% 50%, rgba(30, 136, 229, 0.3) 0%, transparent 50%),
    radial-gradient(circle at 80% 50%, rgba(255, 107, 53, 0.2) 0%, transparent 50%);
}

.page-hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 800px;
  margin: 0 auto;
}

.page-hero h1 {
  color: white;
  margin-bottom: var(--space-4);
  animation: fadeUp 0.8s ease both;
}

.page-hero p {
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--fs-lg);
  animation: fadeUp 0.8s ease 0.15s both;
}

/* ---------- 功能列表(左右交替) ---------- */
.feature-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-16);
  align-items: center;
  margin-bottom: var(--space-24);
}

.feature-row.reverse .feature-row-content {
  order: 2;
}

.feature-row-content .section-eyebrow {
  margin-bottom: var(--space-4);
}

.feature-row-content h3 {
  font-size: var(--fs-3xl);
  margin-bottom: var(--space-4);
  color: var(--color-text);
}

.feature-row-content p {
  font-size: var(--fs-lg);
  line-height: 1.8;
  margin-bottom: var(--space-6);
}

.feature-list {
  margin: var(--space-6) 0;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  font-size: var(--fs-base);
  color: var(--color-text);
}

.feature-list li::before {
  content: '';
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  margin-top: 4px;
  background: var(--gradient-orange);
  border-radius: 50%;
  position: relative;
}

.feature-list li::after {
  content: '✓';
  position: absolute;
  left: 6px;
  top: 6px;
  color: white;
  font-size: 12px;
  font-weight: 700;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.feature-row-visual {
  background: var(--gradient-primary);
  border-radius: var(--radius-2xl);
  padding: var(--space-12);
  min-height: 400px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

.feature-row-visual::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(circle at 30% 30%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
    radial-gradient(circle at 70% 70%, rgba(255, 107, 53, 0.2) 0%, transparent 50%);
}

.visual-icon {
  font-size: 120px;
  position: relative;
  z-index: 1;
  filter: drop-shadow(0 10px 30px rgba(0, 0, 0, 0.3));
}

/* ---------- 对比表格 ---------- */
.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-surface);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
  margin-top: var(--space-8);
}

.comparison-table thead {
  background: var(--gradient-primary);
  color: white;
}

.comparison-table th,
.comparison-table td {
  padding: var(--space-5);
  text-align: center;
  border-bottom: 1px solid var(--color-border);
}

.comparison-table th {
  font-weight: 700;
  font-size: var(--fs-base);
}

.comparison-table th:first-child {
  text-align: left;
}

.comparison-table th.highlight {
  background: var(--gradient-orange);
  position: relative;
}

.comparison-table th.highlight::after {
  content: '推荐';
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-orange);
  color: white;
  font-size: var(--fs-xs);
  padding: 2px 12px;
  border-radius: var(--radius-full);
  font-weight: 600;
}

.comparison-table td:first-child {
  text-align: left;
  font-weight: 500;
  color: var(--color-text);
}

.comparison-table tbody tr:hover {
  background: var(--color-bg-alt);
}

.comparison-table .yes {
  color: var(--color-success);
  font-weight: 700;
  font-size: var(--fs-lg);
}

.comparison-table .no {
  color: var(--color-text-light);
  font-size: var(--fs-lg);
}

/* ---------- 下载卡片 ---------- */
.download-card {
  background: var(--color-surface);
  border-radius: var(--radius-2xl);
  padding: var(--space-12);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}

.download-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0;
  height: 6px;
  background: var(--gradient-orange);
}

.download-header {
  text-align: center;
  margin-bottom: var(--space-8);
}

.download-version {
  font-family: var(--font-mono);
  font-size: var(--fs-5xl);
  font-weight: 800;
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: var(--space-3);
}

.download-meta {
  display: flex;
  justify-content: center;
  gap: var(--space-8);
  flex-wrap: wrap;
  margin-bottom: var(--space-8);
  padding: var(--space-5);
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
}

.meta-item {
  text-align: center;
}

.meta-label {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-1);
}

.meta-value {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--color-text);
  font-size: var(--fs-base);
}

.download-buttons {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  align-items: center;
}

.download-buttons .btn {
  width: 100%;
  max-width: 320px;
}

/* ---------- 网盘下载卡片 ---------- */
.pan-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin-top: var(--space-6);
}

@media (max-width: 768px) {
  .pan-list {
    grid-template-columns: 1fr;
  }
}

.pan-card {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  padding: var(--space-6);
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-decoration: none;
  color: inherit;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.pan-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 4px;
  background: var(--pan-color, var(--color-accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.pan-card:hover {
  transform: translateY(-6px);
  border-color: var(--pan-color, var(--color-accent));
  box-shadow: 0 12px 28px rgba(10, 37, 64, 0.12);
}

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

.pan-header {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.pan-logo {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 800;
  font-size: var(--fs-lg);
  background: var(--pan-color, var(--color-accent));
  flex-shrink: 0;
}

.pan-name {
  font-size: var(--fs-lg);
  font-weight: 700;
  color: var(--color-text);
  margin: 0;
}

.pan-tag {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: 2px;
}

.pan-features {
  list-style: none;
  padding: 0;
  margin: 0 0 var(--space-5);
  flex: 1;
}

.pan-features li {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 4px 0;
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
}

.pan-features li::before {
  content: '✓';
  color: var(--color-success);
  font-weight: 700;
  font-size: var(--fs-xs);
}

.pan-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  background: var(--pan-color, var(--color-accent));
  color: white !important;
  font-weight: 600;
  font-size: var(--fs-base);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  text-decoration: none;
}

.pan-button:hover {
  filter: brightness(1.1);
  transform: translateY(-1px);
}

.pan-button svg {
  width: 18px;
  height: 18px;
}

/* 各网盘品牌色 */
.pan-card.xunlei { --pan-color: #00A1FB; }
.pan-card.quark { --pan-color: #6F55FF; }
.pan-card.baidu { --pan-color: #06A7FF; }

.download-trust {
  display: flex;
  justify-content: center;
  gap: var(--space-6);
  margin-top: var(--space-6);
  flex-wrap: wrap;
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}

.trust-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* ---------- 系统要求 ---------- */
.requirements-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.requirement-card {
  background: var(--color-surface);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-border);
  text-align: center;
  transition: all var(--transition-base);
}

.requirement-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.requirement-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto var(--space-4);
  background: var(--color-bg-alt);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
}

.requirement-title {
  font-weight: 600;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.requirement-detail {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin: 0;
}

/* ---------- 安装步骤 ---------- */
.steps-container {
  counter-reset: step;
  margin-top: var(--space-8);
}

.step-item {
  display: flex;
  gap: var(--space-6);
  padding: var(--space-6) 0;
  border-bottom: 1px solid var(--color-border);
  counter-increment: step;
}

.step-item:last-child {
  border-bottom: none;
}

.step-number {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient-accent);
  color: white;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--fs-lg);
  display: flex;
  align-items: center;
  justify-content: center;
}

.step-content h4 {
  font-size: var(--fs-lg);
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.step-content p {
  color: var(--color-text-secondary);
  font-size: var(--fs-base);
  margin: 0;
}

/* ---------- FAQ 手风琴 ---------- */
.faq-container {
  max-width: 800px;
  margin: 0 auto;
}

.faq-category {
  margin-bottom: var(--space-12);
}

.faq-category-title {
  font-size: var(--fs-2xl);
  font-weight: 700;
  margin-bottom: var(--space-6);
  color: var(--color-text);
  padding-bottom: var(--space-3);
  border-bottom: 3px solid var(--color-orange);
  display: inline-block;
}

.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-3);
  overflow: hidden;
  transition: all var(--transition-base);
}

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

.faq-question {
  padding: var(--space-5) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  font-weight: 600;
  color: var(--color-text);
  transition: color var(--transition-fast);
  font-size: var(--fs-base);
  width: 100%;
  text-align: left;
}

.faq-question:hover {
  color: var(--color-accent);
}

.faq-question .toggle-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-accent);
  transition: transform var(--transition-base);
  font-size: var(--fs-lg);
  font-weight: 700;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), padding var(--transition-slow);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 var(--space-6) var(--space-5);
}

.faq-answer p {
  color: var(--color-text-secondary);
  line-height: 1.8;
  margin: 0;
}

.faq-answer code {
  font-family: var(--font-mono);
  background: var(--color-bg-alt);
  padding: 2px 6px;
  border-radius: var(--radius-sm);
  font-size: var(--fs-sm);
  color: var(--color-orange);
}

/* ---------- 时间线 ---------- */
.timeline {
  position: relative;
  padding-left: var(--space-12);
  margin-top: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 11px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--color-accent) 0%, var(--color-orange) 100%);
}

.timeline-item {
  position: relative;
  padding-bottom: var(--space-10);
}

.timeline-item:last-child {
  padding-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -42px;
  top: 4px;
  width: 24px;
  height: 24px;
  background: white;
  border: 3px solid var(--color-accent);
  border-radius: 50%;
  z-index: 1;
  transition: all var(--transition-base);
}

.timeline-item:hover .timeline-dot {
  background: var(--color-orange);
  border-color: var(--color-orange);
  transform: scale(1.2);
}

.timeline-date {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--color-accent);
  font-weight: 700;
  margin-bottom: var(--space-2);
  padding: var(--space-1) var(--space-3);
  background: rgba(30, 136, 229, 0.1);
  border-radius: var(--radius-full);
}

.timeline-content h4 {
  font-size: var(--fs-lg);
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.timeline-content p {
  color: var(--color-text-secondary);
  font-size: var(--fs-base);
  margin: 0;
}

/* ---------- 联系卡片 ---------- */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-8);
}

.contact-card {
  background: var(--color-surface);
  padding: var(--space-8);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-border);
  text-align: center;
  transition: all var(--transition-base);
}

.contact-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.contact-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-4);
  background: var(--gradient-accent);
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 28px;
}

.contact-card h4 {
  font-size: var(--fs-lg);
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.contact-card p {
  color: var(--color-text-secondary);
  font-size: var(--fs-base);
  margin: 0;
}

.contact-card a {
  color: var(--color-accent);
  font-weight: 600;
}

/* ---------- 教程区块 ---------- */
.tutorial-section {
  margin-bottom: var(--space-16);
}

.tutorial-section h3 {
  font-size: var(--fs-3xl);
  font-weight: 800;
  margin-bottom: var(--space-6);
  padding-bottom: var(--space-3);
  border-bottom: 2px solid var(--color-border);
  position: relative;
}

.tutorial-section h3::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 60px;
  height: 2px;
  background: var(--gradient-orange);
}

.code-block {
  background: var(--color-primary-dark);
  color: #E2E8F0;
  padding: var(--space-5);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  line-height: 1.6;
  overflow-x: auto;
  margin: var(--space-4) 0;
  border-left: 4px solid var(--color-orange);
}

.code-block .comment {
  color: #94A3B8;
}

.code-block .keyword {
  color: #FF8A5C;
}

.code-block .string {
  color: #10B981;
}

.callout {
  background: rgba(30, 136, 229, 0.08);
  border-left: 4px solid var(--color-accent);
  padding: var(--space-4) var(--space-5);
  border-radius: var(--radius-md);
  margin: var(--space-4) 0;
}

.callout.warning {
  background: rgba(245, 158, 11, 0.08);
  border-left-color: var(--color-warning);
}

.callout-title {
  font-weight: 700;
  margin-bottom: var(--space-2);
  color: var(--color-text);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

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

/* ---------- 历史版本表格 ---------- */
.history-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--color-surface);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  margin-top: var(--space-6);
}

.history-table th,
.history-table td {
  padding: var(--space-4) var(--space-5);
  text-align: left;
  border-bottom: 1px solid var(--color-border);
  font-size: var(--fs-sm);
}

.history-table th {
  background: var(--color-bg-alt);
  font-weight: 700;
  color: var(--color-text);
}

.history-table tbody tr:hover {
  background: var(--color-bg-alt);
}

.history-table .version-tag {
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--color-accent);
}

.history-table .badge-new {
  background: var(--color-success);
  color: white;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  font-size: var(--fs-xs);
  font-weight: 600;
}

/* ---------- 滚动触发动画 ---------- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

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

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }
.fade-in-delay-4 { transition-delay: 0.4s; }

/* ---------- 滚动到顶部 ---------- */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 30px;
  width: 48px;
  height: 48px;
  background: var(--gradient-primary);
  color: white;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: var(--shadow-lg);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
  z-index: 999;
  border: none;
  font-size: var(--fs-xl);
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-xl);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-content {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-actions,
  .hero-stats {
    justify-content: center;
  }

  .hero-subtitle {
    margin-left: auto;
    margin-right: auto;
  }

  .version-content,
  .feature-row {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .feature-row.reverse .feature-row-content {
    order: 0;
  }

  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
}

@media (max-width: 768px) {
  :root {
    --fs-6xl: 2.5rem;
    --fs-5xl: 2rem;
    --fs-4xl: 1.75rem;
    --fs-3xl: 1.5rem;
  }

  .nav-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    flex-direction: column;
    background: white;
    padding: var(--space-8) var(--space-6);
    gap: var(--space-4);
    align-items: flex-start;
    transform: translateX(100%);
    transition: transform var(--transition-base);
    box-shadow: var(--shadow-2xl);
    overflow-y: auto;
  }

  .nav-menu.active {
    transform: translateX(0);
  }

  .nav-menu a {
    width: 100%;
    padding: var(--space-3) 0;
    font-size: var(--fs-lg);
  }

  .menu-toggle {
    display: flex;
  }

  .section {
    padding: var(--space-16) 0;
  }

  .hero {
    padding-top: calc(72px + var(--space-12));
    min-height: auto;
  }

  .hero-stats {
    gap: var(--space-4);
    flex-wrap: wrap;
  }

  .stat-value {
    font-size: var(--fs-2xl);
  }

  .hero-floating-badge {
    display: none;
  }

  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

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

  .feature-card,
  .download-card,
  .testimonial-card {
    padding: var(--space-6);
  }

  .version-card {
    padding: var(--space-8);
  }

  .comparison-table {
    font-size: var(--fs-sm);
  }

  .comparison-table th,
  .comparison-table td {
    padding: var(--space-3);
  }

  .step-item {
    flex-direction: column;
    gap: var(--space-3);
  }

  .breadcrumb {
    flex-wrap: wrap;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--space-4);
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

  .hero-actions .btn {
    width: 100%;
  }
}

/* ---------- 打印样式 ---------- */
@media print {
  .site-header,
  .scroll-top,
  .nav-cta,
  .menu-toggle {
    display: none;
  }
}