/* ==========================================================================
   LibreCAD 官方推广网站 - 主样式表
   扁平现代专业风格 | 基于 Logo 配色 (#8ed900 + #4d4d4d)
   ========================================================================== */

/* ---------- 1. 设计令牌 (Design Tokens) ---------- */
:root {
  /* 品牌色 - 来源于 LibreCAD Logo */
  --brand-primary: #8ed900;          /* 主品牌色 - 黄绿 */
  --brand-primary-dark: #6ba300;      /* 深品牌色 - hover */
  --brand-primary-darker: #527d00;   /* 更深 - active */
  --brand-primary-light: #a8e835;    /* 浅品牌色 */
  --brand-primary-bg: #f7fbe0;        /* 极浅绿背景 */
  --brand-primary-soft: #eef9c4;     /* 柔和绿 */
  --brand-accent: #4d4d4d;           /* 中灰辅助色 */
  --brand-accent-dark: #2a2a2a;      /* 深灰 */

  /* 中性色 */
  --gray-900: #1a1a1a;
  --gray-800: #2a2a2a;
  --gray-700: #4d4d4d;
  --gray-600: #6b6b6b;
  --gray-500: #8a8a8a;
  --gray-400: #b3b3b3;
  --gray-300: #d6d6d6;
  --gray-200: #ebebeb;
  --gray-100: #f5f5f5;
  --gray-50: #fafafa;
  --white: #ffffff;

  /* 功能色 */
  --success: #5cb85c;
  --warning: #f0ad4e;
  --error: #d9534f;
  --info: #5bc0de;

  /* 平台色 */
  --windows: #00a4ef;
  --macos: #999999;
  --linux: #e95420;

  /* 排版 */
  --font-sans: "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans CN", "Noto Sans SC", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "JetBrains Mono", Menlo, Monaco, Consolas, "Courier New", monospace;
  --font-size-xs: 0.75rem;   /* 12px */
  --font-size-sm: 0.875rem;  /* 14px */
  --font-size-base: 1rem;    /* 16px */
  --font-size-lg: 1.125rem;  /* 18px */
  --font-size-xl: 1.25rem;    /* 20px */
  --font-size-2xl: 1.5rem;   /* 24px */
  --font-size-3xl: 1.875rem; /* 30px */
  --font-size-4xl: 2.25rem;  /* 36px */
  --font-size-5xl: 3rem;     /* 48px */
  --font-size-6xl: 4rem;     /* 64px */
  --line-height-tight: 1.2;
  --line-height-snug: 1.4;
  --line-height-normal: 1.65;
  --line-height-relaxed: 1.8;

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

  /* 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 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.10), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
  --shadow-brand: 0 8px 24px -8px rgba(142, 217, 0, 0.45);

  /* 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 */
  --container-max: 1200px;
  --container-wide: 1400px;
  --container-narrow: 800px;
}

/* ---------- 2. 基础重置 ---------- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-text-size-adjust: 100%;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--gray-800);
  background-color: var(--white);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

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

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

ul, ol {
  list-style: none;
}

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

/* ---------- 3. 排版 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: var(--line-height-tight);
  color: var(--gray-900);
  letter-spacing: -0.02em;
}

h1 { font-size: var(--font-size-6xl); font-weight: 800; }
h2 { font-size: var(--font-size-5xl); }
h3 { font-size: var(--font-size-3xl); }
h4 { font-size: var(--font-size-2xl); }
h5 { font-size: var(--font-size-xl); }
h6 { font-size: var(--font-size-lg); }

p { margin-bottom: 1rem; }

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

code {
  background: var(--gray-100);
  padding: 0.15rem 0.4rem;
  border-radius: var(--radius-sm);
  color: var(--brand-primary-darker);
}

.highlight {
  color: var(--brand-primary-dark);
  font-weight: 600;
}

/* ---------- 4. 容器与布局 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

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

.section {
  padding: var(--space-12) 0;
}

.section-sm {
  padding: var(--space-8) 0;
}

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

.section-bg-light {
  background: var(--gray-50);
}

.section-bg-brand {
  background: var(--brand-primary-bg);
}

.section-bg-dark {
  background: var(--gray-900);
  color: var(--white);
}

.section-bg-dark h1,
.section-bg-dark h2,
.section-bg-dark h3,
.section-bg-dark h4 {
  color: var(--white);
}

/* 文字对齐 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

/* 区块标题 */
.section-header {
  max-width: 720px;
  margin: 0 auto var(--space-10);
  text-align: center;
}

.section-header .eyebrow {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--brand-primary-dark);
  background: var(--brand-primary-soft);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

.section-header h2 {
  margin-bottom: 1rem;
}

.section-header p {
  font-size: var(--font-size-lg);
  color: var(--gray-600);
  line-height: var(--line-height-relaxed);
}

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.85rem 1.75rem;
  font-size: var(--font-size-base);
  font-weight: 600;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  cursor: pointer;
  white-space: nowrap;
  border: 2px solid transparent;
  text-decoration: none;
  line-height: 1.2;
}

.btn-primary {
  background: var(--brand-primary);
  color: var(--gray-900);
  box-shadow: var(--shadow-brand);
}

.btn-primary:hover {
  background: var(--brand-primary-dark);
  color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 12px 28px -8px rgba(142, 217, 0, 0.55);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  background: var(--white);
  color: var(--gray-900);
  border-color: var(--gray-300);
}

.btn-secondary:hover {
  border-color: var(--brand-primary);
  color: var(--brand-primary-dark);
  background: var(--brand-primary-bg);
  transform: translateY(-2px);
}

.btn-outline {
  background: transparent;
  color: var(--gray-900);
  border-color: var(--gray-300);
}

.btn-outline:hover {
  border-color: var(--brand-primary);
  color: var(--brand-primary-dark);
}

.btn-ghost {
  background: transparent;
  color: var(--gray-700);
}

.btn-ghost:hover {
  background: var(--gray-100);
  color: var(--gray-900);
}

.btn-lg {
  padding: 1.05rem 2.25rem;
  font-size: var(--font-size-lg);
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: var(--font-size-sm);
}

.btn-block {
  width: 100%;
}

.btn-icon {
  width: 40px;
  height: 40px;
  padding: 0;
  border-radius: var(--radius-md);
}

/* ---------- 6. 导航栏 ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.05);
  transition: all var(--transition-base);
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.95);
  box-shadow: var(--shadow-sm);
}

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

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  font-weight: 800;
  font-size: var(--font-size-xl);
  color: var(--gray-900);
  letter-spacing: -0.03em;
}

.navbar-brand img {
  height: 32px;
  width: auto;
}

.navbar-brand .brand-suffix {
  color: var(--brand-primary-dark);
}

.navbar-menu {
  display: flex;
  align-items: center;
  gap: 0.25rem;
}

.navbar-menu a {
  display: inline-block;
  padding: 0.5rem 0.95rem;
  font-size: var(--font-size-sm);
  font-weight: 500;
  color: var(--gray-700);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.navbar-menu a:hover {
  color: var(--brand-primary-dark);
  background: var(--brand-primary-bg);
}

.navbar-menu a.active {
  color: var(--brand-primary-dark);
  background: var(--brand-primary-soft);
  font-weight: 600;
}

.navbar-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-left: 1rem;
}

.navbar-toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
}

.navbar-toggle:hover {
  background: var(--gray-100);
}

.navbar-toggle svg {
  width: 22px;
  height: 22px;
}

/* ---------- 7. Hero 区 ---------- */
.hero {
  position: relative;
  padding: calc(72px + var(--space-16)) 0 var(--space-16);
  background: linear-gradient(180deg, var(--brand-primary-bg) 0%, var(--white) 100%);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -200px;
  right: -200px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(142, 217, 0, 0.15) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -300px;
  left: -200px;
  width: 700px;
  height: 700px;
  background: radial-gradient(circle, rgba(142, 217, 0, 0.08) 0%, transparent 70%);
  pointer-events: none;
}

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

.hero-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
}

.hero-content {
  max-width: 600px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.4rem 0.85rem;
  background: var(--white);
  border: 1px solid var(--brand-primary);
  border-radius: var(--radius-full);
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--brand-primary-dark);
  margin-bottom: 1.5rem;
  box-shadow: var(--shadow-sm);
}

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

@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: 0.5; transform: scale(1.3); }
}

.hero h1 {
  font-size: clamp(2.5rem, 5vw, 4rem);
  line-height: 1.1;
  margin-bottom: 1.5rem;
}

.hero h1 .brand-text {
  color: var(--brand-primary-dark);
}

.hero-subtitle {
  font-size: var(--font-size-xl);
  color: var(--gray-600);
  line-height: var(--line-height-relaxed);
  margin-bottom: 2rem;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem 2rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--gray-200);
}

.hero-meta-item {
  display: flex;
  flex-direction: column;
}

.hero-meta-item .value {
  font-size: var(--font-size-2xl);
  font-weight: 800;
  color: var(--brand-primary-dark);
  line-height: 1;
  margin-bottom: 0.25rem;
}

.hero-meta-item .label {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
}

.hero-visual {
  position: relative;
}

.hero-screenshot {
  width: 100%;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  border: 1px solid var(--gray-200);
}

.hero-floating-card {
  position: absolute;
  background: var(--white);
  border-radius: var(--radius-lg);
  padding: 0.85rem 1.25rem;
  box-shadow: var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: var(--font-size-sm);
  font-weight: 600;
}

.hero-floating-card.top-left {
  top: -20px;
  left: -20px;
  color: var(--brand-primary-dark);
}

.hero-floating-card.bottom-right {
  bottom: 30px;
  right: -20px;
}

.hero-floating-card .icon-circle {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--brand-primary-soft);
  color: var(--brand-primary-dark);
}

/* ---------- 8. 数据带 ---------- */
.stats-band {
  background: var(--gray-900);
  color: var(--white);
  padding: var(--space-8) 0;
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  text-align: center;
}

.stats-item .value {
  font-size: var(--font-size-4xl);
  font-weight: 800;
  color: var(--brand-primary);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stats-item .label {
  font-size: var(--font-size-sm);
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* ---------- 9. 特性卡片 ---------- */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.feature-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 2rem;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.feature-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--brand-primary);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

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

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

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius-lg);
  background: var(--brand-primary-soft);
  color: var(--brand-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1.25rem;
}

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

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

.feature-card p {
  color: var(--gray-600);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  margin: 0;
}

/* ---------- 10. 场景卡片 ---------- */
.scenarios-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.scenario-card {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--gray-200);
  transition: all var(--transition-base);
  min-height: 280px;
  display: flex;
  flex-direction: column;
}

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

.scenario-card-header {
  padding: 1.5rem 1.5rem 0.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.scenario-card-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--brand-primary-soft);
  color: var(--brand-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

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

.scenario-card h4 {
  font-size: var(--font-size-lg);
  margin: 0;
}

.scenario-card-body {
  padding: 0.5rem 1.5rem 1.5rem;
  flex: 1;
}

.scenario-card-body p {
  color: var(--gray-600);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  margin: 0;
}

.scenario-card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1rem;
}

.scenario-card-tag {
  font-size: var(--font-size-xs);
  background: var(--gray-100);
  color: var(--gray-700);
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-full);
}

/* ---------- 11. 用户评价 ---------- */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.testimonial-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 2rem;
  position: relative;
  transition: all var(--transition-base);
}

.testimonial-card:hover {
  box-shadow: var(--shadow-lg);
  border-color: var(--brand-primary);
}

.testimonial-card .quote-mark {
  position: absolute;
  top: 1.5rem;
  right: 1.5rem;
  font-size: 4rem;
  font-family: Georgia, serif;
  color: var(--brand-primary-soft);
  line-height: 1;
}

.testimonial-rating {
  display: flex;
  gap: 0.15rem;
  margin-bottom: 1rem;
  color: var(--brand-primary);
}

.testimonial-rating svg {
  width: 18px;
  height: 18px;
}

.testimonial-text {
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--gray-800);
  margin-bottom: 1.5rem;
  position: relative;
  z-index: 1;
}

.testimonial-author {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  padding-top: 1rem;
  border-top: 1px solid var(--gray-100);
}

.testimonial-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--brand-primary-soft);
  color: var(--brand-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--font-size-lg);
  flex-shrink: 0;
}

.testimonial-author-info .name {
  font-weight: 700;
  color: var(--gray-900);
  font-size: var(--font-size-base);
}

.testimonial-author-info .role {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
}

/* ---------- 12. 对比表格 ---------- */
.comparison-table-wrap {
  overflow-x: auto;
  border-radius: var(--radius-lg);
  border: 1px solid var(--gray-200);
  box-shadow: var(--shadow-sm);
}

.comparison-table {
  width: 100%;
  border-collapse: collapse;
  background: var(--white);
  min-width: 640px;
}

.comparison-table th,
.comparison-table td {
  padding: 1.1rem 1.5rem;
  text-align: left;
  border-bottom: 1px solid var(--gray-200);
}

.comparison-table thead th {
  background: var(--gray-50);
  font-weight: 700;
  color: var(--gray-900);
  font-size: var(--font-size-base);
}

.comparison-table thead th.librecad-col {
  background: var(--brand-primary);
  color: var(--gray-900);
}

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

.comparison-table .check {
  color: var(--brand-primary-dark);
  font-weight: 700;
}

.comparison-table .cross {
  color: var(--gray-400);
}

.comparison-table .check::before { content: "✓ "; }
.comparison-table .cross::before { content: "× "; }

/* ---------- 13. 下载弹窗 (Modal) ---------- */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(26, 26, 26, 0.6);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 2000;
  padding: 1rem;
  opacity: 0;
  transition: opacity var(--transition-base);
}

.modal-overlay.active {
  display: flex;
  opacity: 1;
    left: 0;
  right: 0;
  top: 0;
  bottom: 0;
}
button { outline: none } 
.modal {
  background: var(--white);
  border-radius: var(--radius-2xl);
  max-width: 720px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  position: relative;
  transform: translateY(20px) scale(0.96);
  transition: transform var(--transition-base);
  box-shadow: var(--shadow-xl);
}

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

.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background: var(--gray-100);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  z-index: 1;
}

.modal-close:hover {
  background: var(--gray-200);
  transform: rotate(90deg);
}

.modal-close svg {
  width: 18px;
  height: 18px;
}

.modal-header {
  padding: 2rem 2rem 1rem;
  text-align: center;
  border-bottom: 1px solid var(--gray-100);
}

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

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

.modal-header h3 {
  font-size: var(--font-size-2xl);
  margin-bottom: 0.5rem;
}

.modal-header p {
  color: var(--gray-600);
  font-size: var(--font-size-base);
  margin: 0;
}

.modal-body {
  padding: 1.5rem 2rem 2rem;
}

.modal-qr-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
  margin-bottom: 1.5rem;
}

.modal-qr-item {
  text-align: center;
  padding: 1.5rem 1rem;
  background: var(--gray-50);
  border-radius: var(--radius-lg);
  border: 2px solid transparent;
  transition: all var(--transition-base);
}

.modal-qr-item:hover {
  border-color: var(--brand-primary);
  background: var(--brand-primary-bg);
  transform: translateY(-2px);
}

.modal-qr-item .platform-icon {
  width: 40px;
  height: 40px;
  margin: 0 auto 0.75rem;
  display: flex;
  align-items: center;
  justify-content: center;
}

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

.modal-qr-item img.qr {
  width: 180px;
  height: 180px;
  margin: 0 auto 0.85rem;
  border-radius: var(--radius-md);
  background: var(--white);
  padding: 8px;
  border: 1px solid var(--gray-200);
}

.modal-qr-item .platform-name {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--gray-900);
  margin-bottom: 0.25rem;
}

.modal-qr-item .platform-desc {
  font-size: var(--font-size-xs);
  color: var(--gray-600);
  margin-bottom: 0.75rem;
}

.modal-qr-item .scan-tip {
  font-size: var(--font-size-xs);
  color: var(--brand-primary-dark);
  font-weight: 600;
}

.modal-footer-note {
  text-align: center;
  font-size: var(--font-size-xs);
  color: var(--gray-500);
  padding-top: 1rem;
  border-top: 1px solid var(--gray-100);
}

.modal-footer-note a {
  color: var(--brand-primary-dark);
  font-weight: 600;
}

/* ---------- 14. 平台下载卡 ---------- */
.platform-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.platform-card {
  background: var(--white);
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.platform-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--brand-primary);
  transform: scaleX(0);
  transition: transform var(--transition-base);
  transform-origin: center;
}

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

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

.platform-card-icon {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-lg);
  background: var(--brand-primary-soft);
  color: var(--brand-primary-dark);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 1.25rem;
}

.platform-card-icon svg {
  width: 40px;
  height: 40px;
}

.platform-card h4 {
  font-size: var(--font-size-xl);
  margin-bottom: 0.5rem;
}

.platform-card .version {
  color: var(--brand-primary-dark);
  font-weight: 600;
  margin-bottom: 1rem;
  font-size: var(--font-size-sm);
}

.platform-card .meta {
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin-bottom: 1.5rem;
  line-height: 1.6;
}

.platform-card.windows .platform-card-icon { background: rgba(0, 164, 239, 0.1); color: var(--windows); }
.platform-card.macos .platform-card-icon { background: rgba(153, 153, 153, 0.15); color: var(--gray-700); }
.platform-card.linux .platform-card-icon { background: rgba(233, 84, 32, 0.1); color: var(--linux); }

/* ---------- 15. 折叠面板 (Accordion) ---------- */
.accordion {
  border: 1px solid var(--gray-200);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--white);
}

.accordion-item + .accordion-item {
  border-top: 1px solid var(--gray-200);
}

.accordion-header {
  width: 100%;
  padding: 1.25rem 1.5rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--white);
  font-weight: 600;
  color: var(--gray-900);
  font-size: var(--font-size-base);
  text-align: left;
  transition: background var(--transition-fast);
}

.accordion-header:hover {
  background: var(--gray-50);
}

.accordion-header .chevron {
  width: 20px;
  height: 20px;
  transition: transform var(--transition-base);
  color: var(--brand-primary-dark);
  flex-shrink: 0;
  margin-left: 1rem;
}

.accordion-item.active .accordion-header .chevron {
  transform: rotate(180deg);
}

.accordion-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.accordion-item.active .accordion-body {
  max-height: 800px;
}

.accordion-body-inner {
  padding: 0 1.5rem 1.5rem;
  color: var(--gray-700);
  line-height: var(--line-height-relaxed);
}

/* ---------- 16. 时间线 ---------- */
.timeline {
  position: relative;
  padding-left: 2rem;
  max-width: 720px;
  margin: 0 auto;
}

.timeline::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 8px;
  width: 2px;
  background: var(--gray-200);
}

.timeline-item {
  position: relative;
  padding-bottom: 2.5rem;
}

.timeline-item::before {
  content: "";
  position: absolute;
  left: -2rem;
  top: 6px;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--brand-primary);
  box-shadow: 0 0 0 4px var(--brand-primary-soft);
}

.timeline-item .year {
  font-size: var(--font-size-sm);
  font-weight: 700;
  color: var(--brand-primary-dark);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
}

.timeline-item h4 {
  font-size: var(--font-size-lg);
  margin-bottom: 0.5rem;
}

.timeline-item p {
  color: var(--gray-600);
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  margin: 0;
}

/* ---------- 17. CTA 区 ---------- */
.cta-band {
  background: linear-gradient(135deg, var(--brand-primary) 0%, var(--brand-primary-light) 100%);
  padding: var(--space-12) 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-band::before {
  content: "";
  position: absolute;
  inset: 0;
  background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='60' height='60' viewBox='0 0 60 60'%3E%3Cpath fill='%23ffffff' fill-opacity='0.08' d='M30 0l30 30-30 30L0 30z'/%3E%3C/svg%3E");
  pointer-events: none;
}

.cta-band .container {
  position: relative;
  z-index: 1;
}

.cta-band h2 {
  color: var(--gray-900);
  margin-bottom: 1rem;
}

.cta-band p {
  color: var(--gray-800);
  font-size: var(--font-size-xl);
  margin-bottom: 2rem;
  opacity: 0.9;
}

.cta-band .btn {
  background: var(--gray-900);
  color: var(--white);
}

.cta-band .btn:hover {
  background: var(--gray-800);
  transform: translateY(-2px);
}

.cta-band .btn-secondary {
  background: var(--white);
  color: var(--gray-900);
}

/* ---------- 18. 页脚 ---------- */
.footer {
  background: var(--gray-900);
  color: var(--gray-400);
  padding: var(--space-12) 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer-brand .navbar-brand {
  color: var(--white);
  margin-bottom: 1rem;
}

.footer-brand p {
  color: var(--gray-400);
  font-size: var(--font-size-sm);
  line-height: var(--line-height-relaxed);
  margin-bottom: 1.5rem;
}

.footer-social {
  display: flex;
  gap: 0.5rem;
}

.footer-social a {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: rgba(255, 255, 255, 0.05);
  color: var(--gray-400);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.footer-social a:hover {
  background: var(--brand-primary);
  color: var(--gray-900);
}

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

.footer-col h5 {
  color: var(--white);
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
}

.footer-col ul li {
  margin-bottom: 0.6rem;
}

.footer-col ul li a {
  color: var(--gray-400);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--brand-primary);
}

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: var(--font-size-sm);
}

.footer-bottom .copyright {
  color: var(--gray-500);
}

.footer-bottom .copyright a {
  color: var(--gray-400);
}

.footer-bottom .copyright a:hover {
  color: var(--brand-primary);
}

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

.footer-icp a {
  color: var(--gray-500);
  font-size: var(--font-size-sm);
}

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

/* ---------- 19. 通用辅助 ---------- */
.page-header {
  padding: calc(72px + var(--space-12)) 0 var(--space-10);
  background: linear-gradient(180deg, var(--brand-primary-bg) 0%, var(--white) 100%);
  text-align: center;
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: "";
  position: absolute;
  top: -100px;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(142, 217, 0, 0.12) 0%, transparent 70%);
  pointer-events: none;
}

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

.page-header .eyebrow {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--brand-primary-dark);
  background: var(--brand-primary-soft);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 1rem;
}

.page-header h1 {
  font-size: clamp(2rem, 4vw, 3.5rem);
  margin-bottom: 1rem;
}

.page-header .subtitle {
  font-size: var(--font-size-xl);
  color: var(--gray-600);
  max-width: 640px;
  margin: 0 auto;
  line-height: var(--line-height-relaxed);
}

.breadcrumb {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--font-size-sm);
  color: var(--gray-600);
  margin-bottom: 1rem;
  justify-content: center;
}

.breadcrumb a {
  color: var(--gray-600);
}

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

.breadcrumb .sep {
  color: var(--gray-400);
}

/* 内容块 */
.content-block {
  max-width: 760px;
  margin: 0 auto;
}

.content-block h2 {
  font-size: var(--font-size-3xl);
  margin: 2.5rem 0 1rem;
}

.content-block h3 {
  font-size: var(--font-size-xl);
  margin: 2rem 0 0.75rem;
}

.content-block p {
  font-size: var(--font-size-base);
  line-height: var(--line-height-relaxed);
  color: var(--gray-700);
  margin-bottom: 1rem;
}

.content-block ul,
.content-block ol {
  padding-left: 1.5rem;
  margin-bottom: 1rem;
}

.content-block ul li,
.content-block ol li {
  list-style: disc;
  margin-bottom: 0.5rem;
  color: var(--gray-700);
  line-height: var(--line-height-relaxed);
}

.content-block ol li {
  list-style: decimal;
}

/* ---------- 20. 返回顶部 ---------- */
.back-to-top {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--brand-primary);
  color: var(--gray-900);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-brand);
  opacity: 0;
  visibility: hidden;
  transform: translateY(20px);
  transition: all var(--transition-base);
  z-index: 999;
  border: none;
  cursor: pointer;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  background: var(--brand-primary-dark);
  color: var(--white);
  transform: translateY(-4px);
}

.back-to-top svg {
  width: 22px;
  height: 22px;
}

/* ---------- 21. 滚动动画 ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

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

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

/* ---------- 22. 响应式 ---------- */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  .hero-visual {
    max-width: 600px;
    margin: 0 auto;
  }
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  html { font-size: 15px; }
  .section { padding: var(--space-10) 0; }
  .navbar-menu {
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--white);
    padding: 1rem;
    border-bottom: 1px solid var(--gray-200);
    transform: translateY(-110%);
    transition: transform var(--transition-base);
    align-items: stretch;
    gap: 0.25rem;
    box-shadow: var(--shadow-lg);
    max-height: calc(100vh - 72px);
    overflow-y: auto;
  }
  .navbar-menu.active {
    transform: translateY(0);
  }
  .navbar-menu a {
    padding: 0.85rem 1rem;
    font-size: var(--font-size-base);
  }
  .navbar-toggle {
    display: flex;
  }
  .navbar-actions {
    margin-left: 0;
  }
  .navbar-actions .btn-secondary {
    display: none;
  }
  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 1.5rem;
  }
  .modal-qr-grid {
    grid-template-columns: 1fr;
  }
  .modal-qr-item img.qr {
    width: 160px;
    height: 160px;
  }
  .hero {
    padding: calc(72px + var(--space-10)) 0 var(--space-10);
  }
  .hero-cta {
    flex-direction: column;
  }
  .hero-cta .btn {
    width: 100%;
  }
  .hero-meta {
    gap: 1rem;
  }
  .hero-meta-item .value {
    font-size: var(--font-size-xl);
  }
  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }
  .back-to-top {
    bottom: 1rem;
    right: 1rem;
    width: 44px;
    height: 44px;
  }
  .container {
    padding: 0 1.25rem;
  }
}

@media (max-width: 480px) {
  h1 { font-size: var(--font-size-4xl); }
  h2 { font-size: var(--font-size-3xl); }
  .stats-grid {
    grid-template-columns: 1fr 1fr;
  }
  .modal-header, .modal-body {
    padding-left: 1.25rem;
    padding-right: 1.25rem;
  }
  .feature-card, .scenario-card, .platform-card, .testimonial-card {
    padding: 1.5rem;
  }
}

/* ---------- 23. 无障碍 ---------- */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}

:focus-visible {
  outline: 3px solid var(--brand-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

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