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

:root {
  --primary: #1890ff;
  --primary-dark: #096dd9;
  --primary-light: #e6f7ff;
  --text: #1a1a1a;
  --text-secondary: #666;
  --text-muted: #999;
  --bg: #ffffff;
  --bg-gray: #f5f7fa;
  --border: #e8e8e8;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 48px rgba(24, 144, 255, 0.15);
  --radius: 12px;
  --radius-lg: 20px;
  --header-h: 64px;
  --transition: 0.3s ease;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

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

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

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

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

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

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

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 700;
  font-size: 18px;
  color: var(--text);
}

.logo-icon {
  width: 32px;
  height: 32px;
  color: var(--primary);
}

.nav-list {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  display: block;
  padding: 8px 16px;
  font-size: 15px;
  color: var(--text-secondary);
  border-radius: 8px;
  transition: color var(--transition), background var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
  background: var(--primary-light);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}

.menu-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.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;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: 10px;
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
}

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

.btn-primary:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(24, 144, 255, 0.35);
}

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

.btn-outline:hover {
  background: var(--primary-light);
  transform: translateY(-2px);
}

/* ===== 首屏 Hero ===== */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-h) + 48px) 0 80px;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 80% 60% at 70% 20%, rgba(24, 144, 255, 0.12) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 20% 80%, rgba(24, 144, 255, 0.08) 0%, transparent 50%),
    linear-gradient(180deg, #f0f7ff 0%, #ffffff 60%);
  z-index: -1;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  padding: 6px 14px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 20px;
}

.hero-title {
  font-size: clamp(36px, 5vw, 56px);
  font-weight: 800;
  line-height: 1.15;
  background: linear-gradient(135deg, var(--text) 0%, var(--primary) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}

.hero-subtitle {
  font-size: clamp(18px, 2.5vw, 24px);
  color: var(--primary);
  font-weight: 600;
  margin-bottom: 16px;
}

.hero-desc {
  font-size: 16px;
  color: var(--text-secondary);
  line-height: 1.8;
  max-width: 480px;
  margin-bottom: 32px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 48px;
}

.hero-stats {
  display: flex;
  gap: 40px;
}

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

.stat-num {
  font-size: 32px;
  font-weight: 800;
  color: var(--primary);
  line-height: 1.2;
}

.stat-unit {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
}

.stat-label {
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 4px;
}

/* 手机 mockup */
.hero-visual {
  display: flex;
  justify-content: center;
}

.phone-mockup {
  width: 280px;
  background: linear-gradient(145deg, #2d2d2d, #1a1a1a);
  border-radius: 36px;
  padding: 12px;
  box-shadow: var(--shadow-lg), 0 0 0 1px rgba(255, 255, 255, 0.1);
  animation: float 4s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-12px); }
}

.phone-screen {
  background: #111;
  border-radius: 28px;
  padding: 24px 20px;
  min-height: 420px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.scan-frame {
  position: relative;
  width: 180px;
  height: 180px;
  margin-bottom: 20px;
}

.scan-corner {
  position: absolute;
  width: 24px;
  height: 24px;
  border-color: var(--primary);
  border-style: solid;
}

.scan-corner.tl { top: 0; left: 0; border-width: 3px 0 0 3px; }
.scan-corner.tr { top: 0; right: 0; border-width: 3px 3px 0 0; }
.scan-corner.bl { bottom: 0; left: 0; border-width: 0 0 3px 3px; }
.scan-corner.br { bottom: 0; right: 0; border-width: 0 3px 3px 0; }

.scan-line {
  position: absolute;
  left: 8px;
  right: 8px;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--primary), transparent);
  animation: scan 2s ease-in-out infinite;
}

@keyframes scan {
  0%, 100% { top: 8px; opacity: 0.6; }
  50% { top: calc(100% - 10px); opacity: 1; }
}

.qr-demo {
  position: absolute;
  inset: 20px;
  border-radius: 8px;
  overflow: hidden;
}

.qr-demo svg {
  width: 100%;
  height: 100%;
}

.scan-tip {
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

/* ===== 通用区块 ===== */
.section {
  padding: 96px 0;
}

.section-header {
  text-align: center;
  margin-bottom: 64px;
}

.section-tag {
  display: inline-block;
  padding: 6px 16px;
  background: var(--primary-light);
  color: var(--primary);
  font-size: 13px;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 16px;
}

.section-tag.light {
  background: rgba(255, 255, 255, 0.2);
  color: #fff;
}

.section-title {
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 800;
  margin-bottom: 12px;
}

.section-title.light {
  color: #fff;
}

.section-desc {
  font-size: 16px;
  color: var(--text-secondary);
  max-width: 560px;
  margin: 0 auto;
}

/* ===== 功能区块 ===== */
.features {
  background: var(--bg-gray);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.feature-card {
  background: var(--bg);
  padding: 32px 28px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.feature-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-lg);
  border-color: transparent;
}

.feature-icon {
  width: 52px;
  height: 52px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 14px;
  margin-bottom: 20px;
}

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

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  margin-bottom: 10px;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ===== 关于我们 ===== */
.about-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about-text {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.about-list {
  margin-top: 32px;
}

.about-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}

.about-list li:last-child {
  border-bottom: none;
}

.about-list strong {
  font-size: 14px;
  color: var(--text);
}

.about-list span {
  font-size: 14px;
  color: var(--text-secondary);
}

.about-card {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  color: #fff;
  padding: 48px 40px;
  border-radius: var(--radius-lg);
  text-align: center;
  box-shadow: var(--shadow-lg);
}

.about-card-icon {
  width: 72px;
  height: 72px;
  margin: 0 auto 20px;
  opacity: 0.9;
}

.about-card h3 {
  font-size: 24px;
  font-weight: 700;
  margin-bottom: 4px;
}

.about-card > p {
  font-size: 14px;
  opacity: 0.8;
  margin-bottom: 24px;
}

.about-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
}

.about-tags span {
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 20px;
  font-size: 13px;
}

/* ===== 下载区块 ===== */
.download-box {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 48px;
  align-items: center;
  background: linear-gradient(135deg, var(--primary) 0%, #0050b3 100%);
  border-radius: var(--radius-lg);
  padding: 64px;
  color: #fff;
}

.download-desc {
  font-size: 16px;
  opacity: 0.9;
  margin-bottom: 32px;
}

.download-buttons {
  margin-bottom: 16px;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 16px;
  padding: 16px 28px;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.3);
  border-radius: 14px;
  color: #fff;
  transition: background var(--transition), transform var(--transition);
}

.download-btn:hover {
  background: rgba(255, 255, 255, 0.25);
  transform: translateY(-2px);
}

.download-btn svg {
  width: 36px;
  height: 36px;
  flex-shrink: 0;
}

.download-btn small {
  display: block;
  font-size: 12px;
  opacity: 0.8;
}

.download-btn strong {
  display: block;
  font-size: 15px;
}

.download-note {
  font-size: 13px;
  opacity: 0.7;
}

.download-qr {
  text-align: center;
}

.qr-box {
  width: 160px;
  height: 160px;
  background: #fff;
  border-radius: 12px;
  padding: 10px;
  margin-bottom: 12px;
}

.qr-box svg {
  width: 100%;
  height: 100%;
}

.download-qr p {
  font-size: 14px;
  opacity: 0.9;
}

/* ===== 联系我们 ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.contact-card {
  text-align: center;
  padding: 40px 28px;
  background: var(--bg-gray);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.contact-icon {
  width: 56px;
  height: 56px;
  margin: 0 auto 20px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--primary-light);
  color: var(--primary);
  border-radius: 50%;
}

.contact-icon svg {
  width: 26px;
  height: 26px;
}

.contact-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 8px;
}

.contact-card p {
  font-size: 14px;
  color: var(--text-secondary);
}

/* ===== 页脚 ===== */
.footer {
  background: #0d1117;
  color: rgba(255, 255, 255, 0.7);
  padding-top: 64px;
}

.footer-inner {
  display: grid;
  grid-template-columns: 1.2fr 2fr;
  gap: 48px;
  padding-bottom: 48px;
}

.footer .logo {
  color: #fff;
  margin-bottom: 12px;
}

.footer-desc {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.5);
}

.footer-links {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.footer-col h4 {
  color: #fff;
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 16px;
}

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

.footer-col a {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition);
}

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

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  padding: 20px 0;
  text-align: center;
}

.footer-bottom p {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.4);
}

/* ===== 回到顶部 ===== */
.back-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  background: var(--primary);
  color: #fff;
  border: none;
  border-radius: 12px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(24, 144, 255, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all var(--transition);
  z-index: 999;
}

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

.back-top:hover {
  background: var(--primary-dark);
  transform: translateY(-2px);
}

.back-top svg {
  width: 20px;
  height: 20px;
}

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

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

/* ===== 响应式 - 平板 ===== */
@media (max-width: 1024px) {
  .hero-inner {
    grid-template-columns: 1fr;
    gap: 48px;
    text-align: center;
  }

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

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

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

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

  .about-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .download-box {
    grid-template-columns: 1fr;
    text-align: center;
    padding: 48px 32px;
  }

  .download-buttons {
    display: flex;
    justify-content: center;
  }

  .download-qr {
    display: flex;
    flex-direction: column;
    align-items: center;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 40px;
  }
}

/* ===== 响应式 - 手机 ===== */
@media (max-width: 768px) {
  :root {
    --header-h: 56px;
  }

  .container {
    padding: 0 16px;
  }

  .menu-toggle {
    display: flex;
  }

  .nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    box-shadow: var(--shadow);
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition);
  }

  .nav.open {
    max-height: 320px;
  }

  .nav-list {
    flex-direction: column;
    padding: 12px 16px 20px;
    gap: 4px;
  }

  .nav-link {
    padding: 12px 16px;
    font-size: 16px;
  }

  .hero {
    padding: calc(var(--header-h) + 32px) 0 60px;
    min-height: auto;
  }

  .hero-stats {
    gap: 24px;
    flex-wrap: wrap;
  }

  .stat-num {
    font-size: 26px;
  }

  .phone-mockup {
    width: 240px;
  }

  .phone-screen {
    min-height: 360px;
  }

  .section {
    padding: 64px 0;
  }

  .section-header {
    margin-bottom: 40px;
  }

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

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

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

  .back-top {
    bottom: 20px;
    right: 20px;
    width: 40px;
    height: 40px;
  }
}

@media (max-width: 480px) {
  .hero-actions {
    flex-direction: column;
    width: 100%;
  }

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

  .hero-stats {
    gap: 16px;
  }

  .stat-item {
    flex: 1;
    min-width: 80px;
  }

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

  .about-card {
    padding: 36px 24px;
  }

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