/* Telegram 官方风格落地页 */
:root {
  --tg-blue: #0088cc;
  --tg-blue-dark: #006699;
  --tg-blue-light: #54a9eb;
  --tg-gradient: linear-gradient(135deg, #0088cc 0%, #229ED9 50%, #54a9eb 100%);
  --tg-bg: #ffffff;
  --tg-text: #222222;
  --tg-text-muted: #707579;
  --tg-shadow: 0 8px 32px rgba(0, 136, 204, 0.18);
  --tg-shadow-lg: 0 16px 48px rgba(0, 136, 204, 0.25);
  --radius: 16px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--tg-bg);
  color: var(--tg-text);
  line-height: 1.6;
  min-height: 100vh;
}

a {
  color: var(--tg-blue);
  text-decoration: none;
  transition: color 0.2s;
}

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

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

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

/* Header */
.site-header {
  background: var(--tg-bg);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  position: sticky;
  top: 0;
  z-index: 100;
}

.header-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--tg-text);
}

.logo img {
  width: 36px;
  height: 36px;
}

.logo span {
  color: var(--tg-blue);
}

.nav-links {
  display: flex;
  gap: 28px;
  list-style: none;
}

.nav-links a {
  color: var(--tg-text-muted);
  font-weight: 500;
  font-size: 0.95rem;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--tg-blue);
}

/* Hero - 简洁官方风格 */
.hero {
  text-align: center;
  padding: 56px 24px 40px;
  background: var(--tg-bg);
}

.hero h1 {
  font-size: clamp(1.8rem, 5vw, 2.6rem);
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: 16px;
  color: var(--tg-text);
  letter-spacing: -0.02em;
}

.hero p {
  font-size: clamp(1rem, 2.5vw, 1.15rem);
  color: var(--tg-text-muted);
  max-width: 640px;
  margin: 0 auto 32px;
}

/* Download Buttons */
.download-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  justify-content: center;
}

.btn-download {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  padding: 16px 36px;
  border: none;
  border-radius: var(--radius);
  font-size: 1.05rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.btn-download::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  transform: translateX(-100%);
  transition: transform 0.5s;
}

.btn-download:hover::after {
  transform: translateX(100%);
}

.btn-download:hover {
  transform: translateY(-3px);
}

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

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

.btn-download-primary:hover {
  box-shadow: 0 20px 56px rgba(0, 136, 204, 0.4);
  color: #fff;
}

.btn-download-outline {
  background: #fff;
  color: var(--tg-blue);
  border: 2px solid var(--tg-blue);
  box-shadow: 0 4px 16px rgba(0, 136, 204, 0.12);
}

.btn-download-outline:hover {
  background: rgba(0, 136, 204, 0.05);
  color: var(--tg-blue-dark);
}

.btn-download img,
.btn-download svg {
  width: 24px;
  height: 24px;
  flex-shrink: 0;
}

.btn-download .btn-text small {
  display: block;
  font-size: 0.72rem;
  font-weight: 500;
  opacity: 0.85;
}

.btn-download .btn-text span {
  display: block;
  font-size: 1.05rem;
  line-height: 1.2;
}

.btn-download.loading {
  pointer-events: none;
  opacity: 0.75;
}

.btn-download.loading::before {
  content: "";
  width: 18px;
  height: 18px;
  border: 2px solid currentColor;
  border-top-color: transparent;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

.btn-pulse {
  animation: pulse-glow 2.5s ease-in-out infinite;
}

@keyframes pulse-glow {
  0%, 100% { box-shadow: 0 8px 32px rgba(0, 136, 204, 0.3); }
  50% { box-shadow: 0 8px 48px rgba(0, 136, 204, 0.55), 0 0 0 8px rgba(0, 136, 204, 0.08); }
}

/* ===== 平台展示布局 ===== */
.platform-showcase {
  max-width: 1080px;
  margin: 0 auto;
  padding: 20px 24px 64px;
}

/* 上排：Android + iOS 等高并排 */
.platform-row-top {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: stretch;
  margin-bottom: 56px;
}

.platform-row-top .platform-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
}

.platform-row-top .platform-item-img {
  flex: 1;
  width: 100%;
  height: 380px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 20px;
}

.platform-row-top .platform-item-img img {
  max-height: 100%;
  max-width: 100%;
  width: auto;
  height: auto;
  object-fit: contain;
}

/* 下排：桌面图合并居中 */
.platform-row-bottom {
  text-align: center;
}

.platform-desktop-img {
  max-width: 900px;
  margin: 0 auto 28px;
}

.platform-desktop-img img {
  width: 100%;
  height: auto;
  margin: 0 auto;
}

.platform-desktop-info {
  display: flex;
  justify-content: center;
  gap: 64px;
  flex-wrap: wrap;
}

.platform-desktop-item {
  text-align: center;
}

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

.platform-item-img {
  margin-bottom: 20px;
  overflow: hidden;
}

.platform-item-img img {
  width: 100%;
  height: auto;
  margin: 0 auto;
}

.platform-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 1.15rem;
  color: var(--tg-blue);
  font-weight: 400;
  margin-bottom: 16px;
}

.platform-label img {
  width: 22px;
  height: 27px;
}

.platform-label strong {
  font-weight: 700;
}

.platform-desc {
  color: var(--tg-text-muted);
  font-size: 0.9rem;
  margin-bottom: 16px;
}

.platform-item .btn-download,
.platform-desktop-item .btn-download {
  padding: 12px 28px;
  font-size: 0.95rem;
}

/* Sections */
.section {
  max-width: 1080px;
  margin: 0 auto;
  padding: 64px 24px;
}

.section-title {
  text-align: center;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin-bottom: 12px;
}

.section-subtitle {
  text-align: center;
  color: var(--tg-text-muted);
  max-width: 600px;
  margin: 0 auto 48px;
  font-size: 1.05rem;
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.feature-card {
  background: #f8fbff;
  border-radius: var(--radius);
  padding: 32px 28px;
  border: 1px solid rgba(0, 136, 204, 0.08);
  transition: transform 0.2s, box-shadow 0.2s;
}

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

.feature-icon {
  width: 52px;
  height: 52px;
  background: linear-gradient(135deg, rgba(0,136,204,0.1), rgba(84,169,235,0.15));
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 1.15rem;
  margin-bottom: 10px;
}

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

/* Download Page */
.download-page-header {
  text-align: center;
  padding: 48px 24px 24px;
}

.download-page-header h1 {
  font-size: clamp(1.6rem, 4vw, 2.2rem);
  font-weight: 700;
  margin-bottom: 12px;
  color: var(--tg-text);
}

.download-page-header p {
  color: var(--tg-text-muted);
  max-width: 560px;
  margin: 0 auto 32px;
  font-size: 1.05rem;
}

/* SEO Content */
.seo-content {
  background: #f8fbff;
  border-top: 1px solid rgba(0, 136, 204, 0.08);
  padding: 48px 24px;
}

.seo-content article {
  max-width: 800px;
  margin: 0 auto;
}

.seo-content h2 {
  font-size: 1.4rem;
  margin: 32px 0 14px;
}

.seo-content h2:first-child {
  margin-top: 0;
}

.seo-content p {
  color: var(--tg-text-muted);
  margin-bottom: 14px;
  font-size: 0.98rem;
}

.seo-content ul {
  color: var(--tg-text-muted);
  padding-left: 24px;
  margin-bottom: 14px;
}

.seo-content li {
  margin-bottom: 8px;
}

/* CTA Banner */
.cta-banner {
  background: var(--tg-gradient);
  color: #fff;
  text-align: center;
  padding: 56px 24px;
}

.cta-banner h2 {
  font-size: clamp(1.4rem, 3vw, 1.8rem);
  margin-bottom: 12px;
}

.cta-banner p {
  opacity: 0.9;
  margin-bottom: 28px;
  font-size: 1.05rem;
}

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

.cta-banner .btn-download-outline {
  background: transparent;
  border-color: #fff;
  color: #fff;
}

.cta-banner .btn-download-outline:hover {
  background: rgba(255, 255, 255, 0.15);
  color: #fff;
}

/* Footer */
.site-footer {
  background: #1a1a2e;
  color: rgba(255,255,255,0.7);
  padding: 40px 24px 28px;
  text-align: center;
}

.footer-inner {
  max-width: 1080px;
  margin: 0 auto;
}

.footer-keywords {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
  margin-bottom: 20px;
}

.footer-keywords span {
  background: rgba(255,255,255,0.08);
  padding: 4px 14px;
  border-radius: 20px;
  font-size: 0.82rem;
}

.site-footer p {
  font-size: 0.85rem;
  line-height: 1.8;
}

.site-footer a {
  color: var(--tg-blue-light);
}

/* Breadcrumb */
.breadcrumb {
  max-width: 1080px;
  margin: 0 auto;
  padding: 16px 24px 0;
  font-size: 0.85rem;
  color: var(--tg-text-muted);
}

.breadcrumb a {
  color: var(--tg-blue);
}

.breadcrumb span {
  margin: 0 6px;
}

/* Responsive */
@media (max-width: 768px) {
  .platform-row-top {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .platform-row-top .platform-item-img {
    height: auto;
    min-height: 240px;
  }

  .platform-desktop-info {
    gap: 32px;
  }
}

@media (max-width: 640px) {
  .nav-links {
    gap: 16px;
    font-size: 0.85rem;
  }

  .header-inner {
    padding: 12px 16px;
  }

  .hero {
    padding: 40px 16px 32px;
  }

  .btn-download {
    width: 100%;
    justify-content: center;
    padding: 14px 24px;
  }

  .section {
    padding: 48px 16px;
  }

  .platform-showcase {
    padding: 16px 16px 48px;
  }
}