/* 微PE工具箱官网 - 共用样式表 */
/* 设计理念：现代简洁、动画流畅、SEO友好、响应式 */

:root {
  --primary: #0078D4;
  --primary-dark: #005a9e;
  --primary-light: #2b9fd6;
  --accent: #00bcf2;
  --success: #107c10;
  --warning: #ffb900;
  --danger: #d13438;
  --bg: #ffffff;
  --bg-alt: #f5f7fa;
  --bg-dark: #1a1a2e;
  --text: #1a1a2e;
  --text-light: #6b7280;
  --text-muted: #9ca3af;
  --border: #e5e7eb;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow: 0 4px 6px rgba(0, 0, 0, 0.07), 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15);
  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --gradient: linear-gradient(135deg, #0078D4 0%, #00bcf2 100%);
  --gradient-dark: linear-gradient(135deg, #1a1a2e 0%, #16213e 100%);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scroll-padding-top: 80px;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

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

/* ============ 容器 ============ */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 20px;
}

.container-sm {
  max-width: 800px;
}

/* ============ 头部导航 ============ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  z-index: 1000;
  transition: var(--transition);
}

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

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--text);
}

.logo-icon {
  width: 36px;
  height: 36px;
  background: var(--gradient);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 800;
  font-size: 16px;
  box-shadow: 0 2px 8px rgba(0, 120, 212, 0.3);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
  list-style: none;
}

.nav-menu a {
  display: block;
  padding: 8px 16px;
  color: var(--text);
  font-size: 15px;
  font-weight: 500;
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

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

.nav-menu a.active {
  color: var(--primary);
  background: rgba(0, 120, 212, 0.08);
}

.nav-cta {
  margin-left: 12px;
}

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

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

.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 ============ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius);
  border: none;
  cursor: pointer;
  transition: var(--transition);
  white-space: nowrap;
  font-family: inherit;
}

.btn-primary {
  background: var(--gradient);
  color: #fff;
  box-shadow: 0 4px 12px rgba(0, 120, 212, 0.3);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 120, 212, 0.4);
}

.btn-secondary {
  background: var(--bg-alt);
  color: var(--text);
  border: 1px solid var(--border);
}

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

.btn-lg {
  padding: 16px 36px;
  font-size: 17px;
}

.btn-block {
  width: 100%;
}

/* ============ Hero 区域 ============ */
.hero {
  position: relative;
  padding: 140px 0 80px;
  background: linear-gradient(180deg, #f0f7ff 0%, #ffffff 100%);
  overflow: hidden;
}

.hero::before {
  content: "";
  position: absolute;
  top: -200px;
  right: -200px;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(0, 188, 242, 0.15) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero::after {
  content: "";
  position: absolute;
  bottom: -200px;
  left: -200px;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(0, 120, 212, 0.1) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

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

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  background: rgba(0, 120, 212, 0.1);
  color: var(--primary);
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 24px;
  animation: fadeInDown 0.6s ease;
}

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

.hero h1 {
  font-size: clamp(2.2rem, 5vw, 3.5rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 20px;
  animation: fadeInUp 0.6s ease 0.1s both;
}

.hero h1 .gradient-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-light);
  margin-bottom: 36px;
  animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-actions {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.6s ease 0.3s both;
}

.hero-stats {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 60px;
  padding: 32px;
  background: #fff;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  animation: fadeInUp 0.6s ease 0.4s both;
}

.stat {
  text-align: center;
}

.stat-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1;
}

.stat-label {
  font-size: 13px;
  color: var(--text-light);
  margin-top: 8px;
}

/* ============ 通用区块 ============ */
.section {
  padding: 80px 0;
}

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

.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto 60px;
}

.section-title {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-light);
}

/* ============ 功能卡片 ============ */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.feature-card {
  background: #fff;
  padding: 32px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: var(--transition);
  position: relative;
  overflow: hidden;
}

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

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

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

.feature-icon {
  width: 56px;
  height: 56px;
  border-radius: var(--radius);
  background: linear-gradient(135deg, rgba(0, 120, 212, 0.1), rgba(0, 188, 242, 0.1));
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  margin-bottom: 20px;
}

.feature-card h3 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.feature-card p {
  color: var(--text-light);
  font-size: 0.95rem;
}

/* ============ 下载卡片 ============ */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
  max-width: 800px;
  margin: 0 auto;
}

.download-card {
  background: #fff;
  padding: 36px 32px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--border);
  transition: var(--transition);
  position: relative;
}

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

.download-card.featured {
  border-color: var(--primary);
  background: linear-gradient(180deg, #f0f7ff 0%, #ffffff 100%);
}

.download-card .badge {
  position: absolute;
  top: -12px;
  right: 24px;
  background: var(--gradient);
  color: #fff;
  padding: 4px 12px;
  border-radius: 12px;
  font-size: 12px;
  font-weight: 600;
}

.download-card .version-icon {
  width: 72px;
  height: 72px;
  border-radius: var(--radius);
  background: var(--gradient);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  font-weight: 800;
  margin-bottom: 20px;
  box-shadow: 0 8px 20px rgba(0, 120, 212, 0.25);
}

.download-card h3 {
  font-size: 1.4rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.download-meta {
  list-style: none;
  margin: 20px 0;
  padding: 20px 0;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.download-meta li {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 0.95rem;
}

.download-meta .label {
  color: var(--text-light);
}

.download-meta .value {
  font-weight: 600;
}

.download-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 16px 0 24px;
}

.download-tag {
  padding: 4px 10px;
  background: var(--bg-alt);
  border-radius: 12px;
  font-size: 12px;
  color: var(--text-light);
}

/* ============ 教程步骤 ============ */
.steps {
  max-width: 800px;
  margin: 0 auto;
}

.step {
  display: flex;
  gap: 24px;
  padding: 28px 0;
  border-bottom: 1px solid var(--border);
}

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

.step-num {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: 700;
}

.step-content h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.step-content p {
  color: var(--text-light);
  margin-bottom: 8px;
}

.step-content .tip {
  margin-top: 12px;
  padding: 12px 16px;
  background: rgba(255, 185, 0, 0.1);
  border-left: 3px solid var(--warning);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text);
}

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

.faq-item {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 12px;
  overflow: hidden;
  transition: var(--transition);
}

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

.faq-question {
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  padding: 20px 24px;
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-family: inherit;
}

.faq-question::after {
  content: "+";
  font-size: 24px;
  color: var(--primary);
  transition: var(--transition);
  font-weight: 300;
}

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

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.3s ease, padding 0.3s ease;
  padding: 0 24px;
  color: var(--text-light);
}

.faq-item.active .faq-answer {
  max-height: 500px;
  padding: 0 24px 20px;
}

/* ============ 工具列表 ============ */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.tool-category {
  background: #fff;
  padding: 28px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.tool-category:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}

.tool-category h3 {
  font-size: 1.15rem;
  font-weight: 700;
  margin-bottom: 16px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.tool-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tool-item {
  padding: 6px 12px;
  background: var(--bg-alt);
  border-radius: var(--radius-sm);
  font-size: 0.85rem;
  color: var(--text-light);
  transition: var(--transition);
}

.tool-item:hover {
  background: var(--primary);
  color: #fff;
}

/* ============ 用户评价 ============ */
.testimonials-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 24px;
}

.testimonial {
  background: #fff;
  padding: 28px;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border);
  transition: var(--transition);
}

.testimonial:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.stars {
  color: var(--warning);
  font-size: 1.1rem;
  margin-bottom: 12px;
}

.testimonial-text {
  font-size: 0.95rem;
  color: var(--text);
  margin-bottom: 20px;
  line-height: 1.7;
}

.testimonial-user {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
}

.user-name {
  font-weight: 600;
  font-size: 0.95rem;
}

.user-meta {
  font-size: 0.85rem;
  color: var(--text-light);
}

/* ============ CTA 区域 ============ */
.cta {
  background: var(--gradient-dark);
  color: #fff;
  padding: 80px 0;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(0, 188, 242, 0.2) 0%, transparent 60%);
  border-radius: 50%;
}

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

.cta h2 {
  font-size: clamp(1.8rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.cta p {
  font-size: 1.1rem;
  opacity: 0.9;
  margin-bottom: 32px;
}

.cta .btn-primary {
  background: #fff;
  color: var(--primary);
}

.cta .btn-primary:hover {
  background: var(--bg-alt);
}

/* ============ 面包屑 ============ */
.breadcrumb {
  padding: 100px 0 24px;
  background: var(--bg-alt);
}

.breadcrumb-list {
  display: flex;
  list-style: none;
  gap: 8px;
  font-size: 0.9rem;
  color: var(--text-light);
}

.breadcrumb-list li::after {
  content: "/";
  margin-left: 8px;
  color: var(--text-muted);
}

.breadcrumb-list li:last-child::after {
  content: "";
}

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

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

/* ============ 页面标题 ============ */
.page-header {
  padding: 40px 0;
  text-align: center;
  background: var(--bg-alt);
}

.page-header h1 {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 12px;
}

.page-header p {
  color: var(--text-light);
  font-size: 1.1rem;
}

/* ============ 内容区块 ============ */
.content-block {
  max-width: 800px;
  margin: 0 auto;
}

.content-block h2 {
  font-size: 1.6rem;
  font-weight: 700;
  margin: 32px 0 16px;
}

.content-block h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 24px 0 12px;
}

.content-block p {
  margin-bottom: 16px;
  color: var(--text);
  line-height: 1.8;
}

.content-block ul,
.content-block ol {
  margin: 0 0 16px 24px;
}

.content-block li {
  margin-bottom: 8px;
  line-height: 1.7;
}

.content-block code {
  background: var(--bg-alt);
  padding: 2px 6px;
  border-radius: 4px;
  font-size: 0.9em;
  color: var(--danger);
}

.content-block pre {
  background: var(--bg-dark);
  color: #e0e0e0;
  padding: 16px;
  border-radius: var(--radius);
  overflow-x: auto;
  margin: 16px 0;
}

.content-block pre code {
  background: none;
  color: inherit;
  padding: 0;
}

/* ============ 更新日志 ============ */
.changelog {
  max-width: 800px;
  margin: 0 auto;
}

.changelog-item {
  padding: 24px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  margin-bottom: 16px;
}

.changelog-item h3 {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 1.2rem;
  margin-bottom: 12px;
}

.version-tag {
  display: inline-block;
  padding: 4px 10px;
  background: var(--gradient);
  color: #fff;
  border-radius: 12px;
  font-size: 0.85rem;
  font-weight: 600;
}

.date-tag {
  color: var(--text-light);
  font-size: 0.9rem;
}

.changelog-item h4 {
  font-size: 1rem;
  margin: 16px 0 8px;
  color: var(--primary);
}

.changelog-item ul {
  margin-left: 20px;
}

.changelog-item li {
  margin-bottom: 6px;
  color: var(--text-light);
  font-size: 0.95rem;
}

/* ============ 表格 ============ */
.table {
  width: 100%;
  background: #fff;
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border);
}

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

.table th {
  background: var(--bg-alt);
  font-weight: 600;
  font-size: 0.95rem;
}

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

.table tr:hover td {
  background: var(--bg-alt);
}

/* ============ 页脚 ============ */
.footer {
  background: var(--bg-dark);
  color: #cbd5e1;
  padding: 60px 0 24px;
}

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

.footer-brand .logo {
  color: #fff;
  margin-bottom: 16px;
}

.footer-brand p {
  color: #94a3b8;
  font-size: 0.9rem;
  line-height: 1.7;
  margin-bottom: 16px;
}

.footer-col h4 {
  color: #fff;
  font-size: 1rem;
  margin-bottom: 16px;
  font-weight: 600;
}

.footer-col ul {
  list-style: none;
}

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

.footer-col a {
  color: #94a3b8;
  font-size: 0.9rem;
  transition: var(--transition);
}

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

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  text-align: center;
  font-size: 0.85rem;
  color: #64748b;
}

.footer-bottom a {
  color: #94a3b8;
}

/* ============ 提示框 ============ */
.alert {
  padding: 16px 20px;
  border-radius: var(--radius);
  margin: 20px 0;
  display: flex;
  gap: 12px;
  align-items: flex-start;
}

.alert-info {
  background: rgba(0, 120, 212, 0.08);
  border-left: 3px solid var(--primary);
  color: var(--text);
}

.alert-warning {
  background: rgba(255, 185, 0, 0.1);
  border-left: 3px solid var(--warning);
  color: var(--text);
}

/* ============ 动画 ============ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeInDown {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
    transform: scale(1);
  }
  50% {
    opacity: 0.6;
    transform: scale(1.2);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

/* 滚动显现动画 */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

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

/* ============ 响应式 ============ */
@media (max-width: 968px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: 32px;
  }
  
  .footer-brand {
    grid-column: 1 / -1;
  }
}

@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background: #fff;
    flex-direction: column;
    align-items: stretch;
    padding: 16px;
    gap: 4px;
    box-shadow: var(--shadow-lg);
    transform: translateY(-150%);
    transition: transform 0.3s ease;
    max-height: calc(100vh - 64px);
    overflow-y: auto;
  }
  
  .nav-menu.active {
    transform: translateY(0);
  }
  
  .nav-menu a {
    padding: 12px 16px;
  }
  
  .nav-cta {
    margin: 8px 0 0;
  }
  
  .nav-toggle {
    display: flex;
  }
  
  .hero {
    padding: 110px 0 60px;
  }
  
  .hero-stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    padding: 24px;
  }
  
  .stat-num {
    font-size: 26px;
  }
  
  .section {
    padding: 60px 0;
  }
  
  .step {
    flex-direction: column;
    gap: 12px;
  }
  
  .footer-grid {
    grid-template-columns: 1fr;
    gap: 28px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 16px;
  }
  
  .hero-actions {
    flex-direction: column;
  }
  
  .hero-actions .btn {
    width: 100%;
  }
  
  .download-card {
    padding: 28px 24px;
  }
}

/* ============ 工具类 ============ */
.text-center { text-align: center; }
.mt-0 { margin-top: 0; }
.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }
.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }
.hidden { display: none; }

/* 链接列表（侧边/底部） */
.link-list {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin: 24px 0;
}

.link-list a {
  padding: 8px 14px;
  background: var(--bg-alt);
  border-radius: var(--radius-sm);
  font-size: 0.9rem;
  color: var(--text-light);
  transition: var(--transition);
}

.link-list a:hover {
  background: var(--primary);
  color: #fff;
}