/* ==========================================================================
   darktable.cn 官方推广网站样式表
   设计风格：扁平现代专业 | 明亮主题 + 鲜亮品牌红
   ========================================================================== */

/* ---------- 设计变量 ---------- */
:root {
  /* 主色调 - 明亮基底 */
  --bg-primary: #ffffff;
  --bg-secondary: #f7f8fa;
  --bg-tertiary: #eef0f4;
  --bg-elevated: #ffffff;

  /* 品牌色 - darktable 标志性红（更鲜亮） */
  --accent-red: #e63946;
  --accent-red-dark: #c1121f;
  --accent-red-light: #ff5a6e;
  --accent-orange: #f77f00;
  --accent-yellow: #fcbf49;
  --gradient-red: linear-gradient(135deg, #e63946 0%, #f77f00 100%);
  --gradient-warm: linear-gradient(135deg, #f77f00 0%, #fcbf49 100%);
  --gradient-hero: linear-gradient(135deg, #fff5f5 0%, #fff8ec 100%);
  --gradient-dark: linear-gradient(180deg, #f7f8fa 0%, #eef0f4 100%);

  /* 文字色 */
  --text-primary: #1a1a2e;
  --text-secondary: #4a4a68;
  --text-muted: #6b7280;
  --text-dim: #9ca3af;

  /* 边框/分隔 */
  --border-color: #e5e7eb;
  --border-light: #f1f3f7;

  /* 阴影 */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 28px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.12);
  --shadow-red: 0 8px 24px rgba(230, 57, 70, 0.28);
  --shadow-warm: 0 8px 24px rgba(247, 127, 0, 0.25);

  /* 间距系统 */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2.5rem;
  --space-xl: 4rem;
  --space-2xl: 6rem;

  /* 圆角 */
  --radius-sm: 4px;
  --radius-md: 8px;
  --radius-lg: 16px;
  --radius-full: 999px;

  /* 字体 */
  --font-sans: 'Inter', 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  /* 布局 */
  --container-max: 1200px;
  --header-height: 70px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  min-height: 100vh;
  overflow-x: hidden;
}

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

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

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

ul, ol {
  list-style: none;
}

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

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

.container-narrow {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ---------- 顶部导航 ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-light);
  z-index: 1000;
  transition: var(--transition);
}

.site-header.scrolled {
  background: rgba(255, 255, 255, 0.98);
  box-shadow: var(--shadow-sm);
}

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

.logo-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  color: var(--text-primary);
}

.logo-link:hover {
  color: var(--text-primary);
}

.logo-link img {
  height: 32px;
  width: auto;
}

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

.nav-menu a {
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  padding: 0.5rem 0;
  position: relative;
  transition: var(--transition);
}

.nav-menu a::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-red);
  transform: scaleX(0);
  transition: transform 0.3s ease;
}

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

.nav-menu a:hover::after,
.nav-menu a.active::after {
  transform: scaleX(1);
}

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

.btn-download-nav {
  padding: 0.55rem 1.4rem;
  background: var(--gradient-red);
  color: #fff !important;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9rem;
  transition: var(--transition);
  box-shadow: var(--shadow-red);
}

.btn-download-nav:hover {
  transform: translateY(-1px);
  box-shadow: 0 14px 32px rgba(230, 57, 70, 0.42);
}

.btn-download-nav::after {
  display: none;
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 0.5rem;
}

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

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

/* ---------- 按钮系统 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.8rem 1.8rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  cursor: pointer;
  border: 1px solid transparent;
  text-align: center;
}

.btn-primary {
  background: var(--gradient-red);
  color: #fff;
  box-shadow: var(--shadow-red);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 36px rgba(230, 57, 70, 0.48);
  color: #fff;
}

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

.btn-secondary:hover {
  background: var(--bg-tertiary);
  border-color: var(--accent-red);
  color: var(--text-primary);
  transform: translateY(-2px);
}

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

.btn-outline:hover {
  border-color: var(--accent-red);
  color: var(--accent-red-light);
}

.btn-lg {
  padding: 1rem 2.4rem;
  font-size: 1.05rem;
}

.btn-icon {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* ---------- 通用区块 ---------- */
section {
  padding: var(--space-2xl) 0;
  position: relative;
}

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

.section-eyebrow {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent-red);
  margin-bottom: var(--space-sm);
  padding: 0.3rem 0.9rem;
  background: rgba(230, 57, 70, 0.08);
  border-radius: var(--radius-full);
  border: 1px solid rgba(230, 57, 70, 0.2);
}

.section-title {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  line-height: 1.7;
}

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

/* ---------- Hero 区 ---------- */
.hero {
  padding-top: calc(var(--header-height) + var(--space-2xl));
  padding-bottom: var(--space-2xl);
  background:
    radial-gradient(ellipse 80% 60% at top right, rgba(247, 127, 0, 0.18), transparent 60%),
    radial-gradient(ellipse 70% 60% at bottom left, rgba(230, 57, 70, 0.14), transparent 55%),
    linear-gradient(180deg, #fffaf3 0%, #fff5f5 50%, #ffffff 100%);
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0; left: 0; right: 0; bottom: 0;
  background-image:
    linear-gradient(rgba(230, 57, 70, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(230, 57, 70, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}

.hero-content {
  position: relative;
  z-index: 1;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 1rem;
  background: rgba(230, 57, 70, 0.1);
  border: 1px solid rgba(230, 57, 70, 0.3);
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  color: var(--accent-red-dark);
  font-weight: 500;
  margin-bottom: var(--space-lg);
}

.hero-badge .dot {
  width: 8px;
  height: 8px;
  background: var(--accent-red);
  border-radius: 50%;
  animation: pulse 2s ease-in-out infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.6; transform: scale(1.3); }
}

.hero h1 {
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: var(--space-md);
}

.hero-tagline {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto var(--space-xl);
  line-height: 1.7;
}

.hero-cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: center;
  margin-bottom: var(--space-xl);
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-md);
  max-width: 800px;
  margin: 0 auto;
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--border-light);
  border-bottom: 1px solid var(--border-light);
}

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

.stat-value {
  font-size: clamp(1.5rem, 3vw, 2.2rem);
  font-weight: 700;
  color: var(--text-primary);
  display: block;
  letter-spacing: -0.02em;
}

.stat-value .accent {
  color: var(--accent-red);
}

.stat-label {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

/* ---------- 特性卡片网格 ---------- */
.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.feature-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0; left: 0;
  width: 100%;
  height: 3px;
  background: var(--gradient-red);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform 0.4s ease;
}

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

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

.feature-icon {
  width: 48px;
  height: 48px;
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.12), rgba(247, 127, 0, 0.12));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: var(--space-md);
  color: var(--accent-red);
}

.feature-icon svg {
  width: 24px;
  height: 24px;
}

.feature-card h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

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

/* ---------- 使用场景 ---------- */
.scenarios-section {
  background: var(--bg-secondary);
}

.scenario-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.scenario-card {
  background: var(--bg-tertiary);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--border-light);
  transition: var(--transition);
}

.scenario-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.scenario-banner {
  height: 180px;
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.1) 0%, rgba(247, 127, 0, 0.15) 100%);
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.scenario-banner svg {
  width: 80px;
  height: 80px;
  color: var(--accent-red);
  opacity: 0.9;
}

.scenario-banner::after {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(circle at center, rgba(247, 127, 0, 0.18), transparent 70%);
}

.scenario-body {
  padding: var(--space-lg);
}

.scenario-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-red);
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.scenario-body h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 0.6rem;
}

.scenario-body p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-bottom: var(--space-sm);
}

.scenario-points {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.scenario-points li {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.scenario-points li::before {
  content: '';
  flex-shrink: 0;
  width: 6px;
  height: 6px;
  margin-top: 8px;
  background: var(--accent-red);
  border-radius: 50%;
}

/* ---------- 用户评价 ---------- */
.testimonials-section {
  background: var(--bg-primary);
  position: relative;
}

.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-md);
}

.testimonial-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  position: relative;
  transition: var(--transition);
}

.testimonial-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-3px);
}

.testimonial-quote-mark {
  position: absolute;
  top: var(--space-md);
  right: var(--space-lg);
  font-family: Georgia, serif;
  font-size: 4rem;
  line-height: 1;
  color: var(--accent-red);
  opacity: 0.2;
}

.testimonial-rating {
  display: flex;
  gap: 2px;
  margin-bottom: var(--space-sm);
  color: var(--accent-orange);
}

.testimonial-rating svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}

.testimonial-text {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.75;
  margin-bottom: var(--space-md);
  position: relative;
  z-index: 1;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding-top: var(--space-sm);
  border-top: 1px solid var(--border-light);
}

.author-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient-red);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 600;
  font-size: 1rem;
  flex-shrink: 0;
}

.author-info {
  flex: 1;
}

.author-name {
  font-weight: 600;
  color: var(--text-primary);
  font-size: 0.95rem;
}

.author-title {
  font-size: 0.82rem;
  color: var(--text-muted);
}

/* ---------- 下载弹窗 ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(26, 26, 46, 0.55);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  opacity: 0;
  visibility: hidden;
  transition: var(--transition);
  padding: var(--space-md);
}

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

.modal-content {
  background: #ffffff;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
  max-width: 720px;
  width: 100%;
  position: relative;
  transform: scale(0.95) translateY(20px);
  transition: var(--transition);
  box-shadow: 0 24px 80px rgba(230, 57, 70, 0.18), var(--shadow-lg);
}

.modal-overlay.active .modal-content {
  transform: scale(1) translateY(0);
}

.modal-close {
  position: absolute;
  top: var(--space-md);
  right: var(--space-md);
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--bg-elevated);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  font-size: 1.3rem;
  line-height: 1;
}

.modal-close:hover {
  background: var(--accent-red);
  color: #fff;
  transform: rotate(90deg);
}

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

.modal-header h3 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.modal-header p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.qr-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.qr-card {
  background: var(--bg-tertiary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  text-align: center;
  transition: var(--transition);
}

.qr-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-2px);
}

.qr-image {
  width: 180px;
  height: 180px;
  margin: 0 auto var(--space-sm);
  background: #fff;
  border-radius: var(--radius-md);
  padding: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.qr-image svg,
.qr-image canvas {
  width: 100%;
  height: 100%;
}

.qr-platform {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.qr-platform svg {
  width: 18px;
  height: 18px;
}

.qr-desc {
  font-size: 0.82rem;
  color: var(--text-muted);
}

.modal-footer {
  text-align: center;
  padding-top: var(--space-md);
  border-top: 1px solid var(--border-light);
  font-size: 0.85rem;
  color: var(--text-muted);
}

.modal-footer a {
  color: var(--accent-red);
  font-weight: 500;
}

/* ---------- 通用页面头部 ---------- */
.page-hero {
  padding-top: calc(var(--header-height) + var(--space-xl));
  padding-bottom: var(--space-xl);
  background:
    radial-gradient(ellipse 80% 60% at top, rgba(247, 127, 0, 0.18), transparent 60%),
    radial-gradient(ellipse 70% 60% at bottom right, rgba(230, 57, 70, 0.12), transparent 55%),
    linear-gradient(180deg, #fffaf3 0%, #fff5f5 50%, #ffffff 100%);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(230, 57, 70, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(230, 57, 70, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  pointer-events: none;
}

.page-hero .container {
  position: relative;
  z-index: 1;
}

.breadcrumb {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

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

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

.breadcrumb-sep {
  color: var(--text-dim);
}

.page-title {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
}

.page-subtitle {
  font-size: 1.1rem;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ---------- 下载页平台卡片 ---------- */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
  margin-bottom: var(--space-xl);
}

.platform-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  text-align: center;
  transition: var(--transition);
  position: relative;
}

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

.platform-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto var(--space-md);
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.12), rgba(247, 127, 0, 0.12));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent-red);
}

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

.platform-card h3 {
  font-size: 1.3rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.platform-version {
  color: var(--accent-red);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

.platform-card .platform-meta {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
  line-height: 1.6;
}

.platform-card .btn {
  width: 100%;
}

/* ---------- 系统要求 ---------- */
.sys-requirements {
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: var(--space-xl);
}

.sys-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.sys-col h4 {
  font-size: 1.05rem;
  color: var(--text-primary);
  margin-bottom: var(--space-sm);
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--accent-red);
  display: inline-block;
}

.sys-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.sys-col li {
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding-left: 1rem;
  position: relative;
  line-height: 1.6;
}

.sys-col li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.6rem;
  width: 5px;
  height: 5px;
  background: var(--accent-red);
  border-radius: 50%;
}

/* ---------- 安装步骤 ---------- */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-md);
}

.step-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  position: relative;
  transition: var(--transition);
}

.step-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-3px);
}

.step-number {
  position: absolute;
  top: -16px;
  left: var(--space-lg);
  width: 40px;
  height: 40px;
  background: var(--gradient-red);
  color: #fff;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 1.1rem;
  box-shadow: var(--shadow-red);
}

.step-card h4 {
  font-size: 1.1rem;
  margin: var(--space-sm) 0 0.5rem;
  font-weight: 600;
}

.step-card p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.65;
}

/* ---------- 教程列表 ---------- */
.tutorial-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}

.tutorial-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: var(--transition);
  display: flex;
  flex-direction: column;
}

.tutorial-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.tutorial-thumb {
  height: 160px;
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.1) 0%, rgba(247, 127, 0, 0.18) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.tutorial-thumb svg {
  width: 48px;
  height: 48px;
  color: var(--accent-red);
}

.tutorial-level {
  position: absolute;
  top: var(--space-sm);
  left: var(--space-sm);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.2rem 0.6rem;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid var(--accent-red);
  color: var(--accent-red-dark);
  border-radius: var(--radius-sm);
  backdrop-filter: blur(4px);
}

.tutorial-body {
  padding: var(--space-md);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.tutorial-body h4 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--text-primary);
}

.tutorial-body p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
  margin-bottom: var(--space-sm);
  flex: 1;
}

.tutorial-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--border-light);
}

.tutorial-link {
  color: var(--accent-red);
  font-weight: 500;
}

.tutorial-link:hover {
  color: var(--accent-orange);
}

/* ---------- 社区卡片 ---------- */
.community-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.community-card {
  background: var(--bg-secondary);
  border: 1px solid var(--border-light);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  transition: var(--transition);
}

.community-card:hover {
  border-color: var(--accent-red);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.community-card .feature-icon {
  background: linear-gradient(135deg, rgba(230, 57, 70, 0.12), rgba(247, 127, 0, 0.12));
}

.community-card h4 {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.community-card p {
  color: var(--text-secondary);
  font-size: 0.92rem;
  line-height: 1.65;
  margin-bottom: var(--space-sm);
}

.community-card .community-link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  color: var(--accent-red-light);
  font-weight: 500;
  font-size: 0.9rem;
}

/* ---------- 时间线 ---------- */
.timeline {
  max-width: 800px;
  margin: 0 auto;
  position: relative;
  padding-left: 2rem;
}

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

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

.timeline-item::before {
  content: '';
  position: absolute;
  left: -2rem;
  top: 0.3rem;
  width: 18px;
  height: 18px;
  background: var(--bg-primary);
  border: 3px solid var(--accent-red);
  border-radius: 50%;
  z-index: 1;
}

.timeline-year {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent-red);
  margin-bottom: 0.3rem;
}

.timeline-item h4 {
  font-size: 1.1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.timeline-item p {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.7;
}

/* ---------- CTA 区 ---------- */
.cta-section {
  background:
    radial-gradient(ellipse 60% 80% at center, rgba(247, 127, 0, 0.16), transparent 70%),
    radial-gradient(ellipse 60% 80% at center, rgba(230, 57, 70, 0.12), transparent 70%),
    linear-gradient(180deg, #fff5f0 0%, #fff8ec 100%);
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  text-align: center;
}

.cta-section h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 700;
  margin-bottom: var(--space-sm);
  letter-spacing: -0.02em;
}

.cta-section p {
  color: var(--text-secondary);
  font-size: 1.05rem;
  margin-bottom: var(--space-lg);
  max-width: 580px;
  margin-left: auto;
  margin-right: auto;
}

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

/* ---------- 页脚 ---------- */
.site-footer {
  background: linear-gradient(180deg, #1a1a2e 0%, #16213e 100%);
  color: #d1d5db;
  padding: var(--space-xl) 0 var(--space-lg);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr repeat(3, 1fr);
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand .logo-link {
  margin-bottom: var(--space-sm);
}

.footer-brand p {
  color: #9ca3af;
  font-size: 0.9rem;
  line-height: 1.7;
  max-width: 320px;
}

.footer-col h5 {
  font-size: 0.95rem;
  font-weight: 600;
  color: #ffffff;
  margin-bottom: var(--space-sm);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-col a {
  color: #9ca3af;
  font-size: 0.9rem;
  transition: var(--transition);
}

.footer-col a:hover {
  color: var(--accent-red-light);
}

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

.footer-bottom p {
  color: #9ca3af;
  font-size: 0.85rem;
}

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

.footer-social a {
  width: 36px;
  height: 36px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #d1d5db;
  transition: var(--transition);
}

.footer-social a:hover {
  background: var(--accent-red);
  color: #fff;
  transform: translateY(-2px);
}

.footer-social svg {
  width: 18px;
  height: 18px;
}

/* ---------- 通用工具类 ---------- */
.text-center { text-align: center; }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }

/* ---------- 响应式 ---------- */
@media (max-width: 968px) {
  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: #ffffff;
    flex-direction: column;
    align-items: stretch;
    padding: var(--space-md) var(--space-lg);
    gap: 0;
    border-bottom: 1px solid var(--border-color);
    transform: translateY(-150%);
    transition: var(--transition);
    box-shadow: var(--shadow-md);
  }

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

  .nav-menu a {
    padding: 0.9rem 0;
    border-bottom: 1px solid var(--border-light);
  }

  .nav-menu a::after {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-cta {
    display: none;
  }

  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }

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

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

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

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

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

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

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

@media (max-width: 600px) {
  section {
    padding: var(--space-xl) 0;
  }

  .container, .container-narrow {
    padding: 0 var(--space-md);
  }

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

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

  .hero-stats {
    grid-template-columns: 1fr 1fr;
  }

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

  .modal-content {
    padding: var(--space-md);
  }

  .qr-image {
    width: 140px;
    height: 140px;
  }

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

/* ---------- 滚动动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.7s ease, transform 0.7s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 选中文本 ---------- */
::selection {
  background: var(--accent-red);
  color: #fff;
}

/* ---------- 滚动条 ---------- */
::-webkit-scrollbar {
  width: 10px;
  height: 10px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: rgba(230, 57, 70, 0.4);
  border-radius: 5px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-red);
}