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

:root {
  --header-h: 64px;
  --text: #474f5e;
  --muted: #8a93a6;
  --blue: #3187d7;
  --dark: #000;
  --dark-2: #0a0a12;
  --footer: #000b2e;
  --data-bg: #eef5fb;
  --card: #fff;
  --radius: 8px;
  --max: 1200px;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  color: #fff;
  background: #000;
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

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

ul {
  list-style: none;
}

/* Header */
.sky-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-h);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0 24px;
  color: var(--text);
  background: #f9f9f9;
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.04);
}

.sky-header .logo img {
  height: 27px;
  width: auto;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 0;
  height: 27px;
  margin-top: -5px;
}

.header-right .divider {
  width: 1px;
  height: 14px;
  background: #d7dbe7;
  margin: 0 16px;
}

.lang-wrap {
  position: relative;
}

.lang-btn,
.help-btn,
.login-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  font-size: 14px;
  padding: 4px 0;
}

.lang-btn svg {
  width: 16px;
  height: 16px;
}

.lang-menu {
  display: none;
  position: absolute;
  top: 32px;
  right: 0;
  min-width: 120px;
  background: #fff;
  border-radius: 6px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
  padding: 6px 0;
  z-index: 20;
}

.lang-menu.open {
  display: block;
}

.lang-menu a {
  display: block;
  padding: 8px 16px;
  font-size: 13px;
  color: var(--text);
}

.lang-menu a:hover,
.lang-menu a.active {
  color: var(--blue);
  background: #f5f8fc;
}

/* Side dots */
.side-nav {
  position: fixed;
  left: 18px;
  top: 50%;
  transform: translateY(-50%);
  z-index: 900;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.side-nav button {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: #e9edf3;
  opacity: 0.85;
  transition: background 0.2s, transform 0.2s;
}

.side-nav button.active {
  background: var(--blue);
  transform: scale(1.1);
}

/* Hero */
.hero {
  position: relative;
  margin-top: var(--header-h);
  height: calc(100vh - var(--header-h));
  min-height: 560px;
  overflow: hidden;
  background: #000;
}

.hero-track {
  display: flex;
  height: 100%;
  transition: transform 0.55s ease;
}

.hero-slide {
  position: relative;
  flex: 0 0 100%;
  width: 100%;
  height: 100%;
  background: #000 center / cover no-repeat;
}

.hero-slide::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(90deg, rgba(0, 0, 0, 0.55) 0%, rgba(0, 0, 0, 0.15) 55%, rgba(0, 0, 0, 0.35) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  height: 100%;
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 48px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.hero-content.center {
  align-items: center;
  text-align: center;
}

.hero-title {
  font-size: clamp(28px, 3.2vw, 42px);
  font-weight: 600;
  margin-bottom: 20px;
  letter-spacing: 0.5px;
}

.hero-desc {
  max-width: 640px;
  font-size: 15px;
  color: rgba(255, 255, 255, 0.88);
  margin-bottom: 8px;
}

.hero-content.center .hero-desc {
  max-width: 720px;
}

.btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-top: 28px;
  min-width: 140px;
  height: 42px;
  padding: 0 28px;
  border: 1px solid rgba(255, 255, 255, 0.85);
  border-radius: 4px;
  color: #fff;
  font-size: 15px;
  transition: background 0.2s, color 0.2s;
}

.btn-ghost:hover {
  background: #fff;
  color: #111;
}

.hero-dots {
  position: absolute;
  left: 50%;
  bottom: 30px;
  transform: translateX(-50%);
  z-index: 5;
  display: flex;
  gap: 10px;
  padding: 6px;
}

.hero-dots button {
  width: 12px;
  height: 12px;
  border-radius: 12px;
  background: #d9d9d9;
  opacity: 0.55;
  transition: width 0.25s, opacity 0.25s, background 0.25s;
}

.hero-dots button.active {
  width: 28px;
  opacity: 1;
  background: #fff;
}

/* Feature sections */
.section {
  position: relative;
  padding: 72px 24px 80px;
  background: #fff;
  overflow: hidden;
}

.section-inner {
  position: relative;
  z-index: 1;
  max-width: var(--max);
  margin: 0 auto;
}

.section-title {
  text-align: center;
  font-size: 28px;
  font-weight: 600;
  margin-bottom: 48px;
  color: #1a1a1a;
}

.feature-grid {
  display: grid;
  gap: 28px 20px;
}

.feature-grid.cols-4 {
  grid-template-columns: repeat(4, 1fr);
}

.feature-grid.cols-5 {
  grid-template-columns: repeat(5, 1fr);
}

.feature-grid.cols-3 {
  grid-template-columns: repeat(3, 1fr);
}

.feature-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 28px 18px 24px;
  background: #fff;
  border: 1px solid #e6ebf2;
  border-radius: 10px;
  box-shadow: 0 6px 18px rgba(36, 80, 140, 0.06);
  transition: box-shadow 0.2s, border-color 0.2s;
}

.feature-card:hover {
  border-color: #cfd9e8;
  box-shadow: 0 10px 24px rgba(36, 80, 140, 0.1);
}

.feature-card .icon {
  width: 88px;
  height: 88px;
  margin-bottom: 18px;
  border-radius: 50%;
  overflow: hidden;
  background: #fff;
  border: 1px solid #d7e0ec;
  box-shadow: 0 2px 8px rgba(49, 135, 215, 0.08);
}

.feature-card .icon img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.feature-card h4 {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 10px;
  color: #1a1a1a;
}

.feature-card p {
  font-size: 13px;
  color: #666;
  line-height: 1.7;
}

/* Data display */
.data-section {
  background: var(--data-bg);
  color: #242833;
  padding: 72px 24px 80px;
}

.data-section .section-title {
  color: #242833;
}

.data-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  max-width: 960px;
  margin: 0 auto;
}

.data-card {
  background: var(--card);
  border-radius: 12px;
  padding: 36px 20px;
  text-align: center;
  box-shadow: 0 8px 28px rgba(36, 80, 140, 0.08);
}

.data-card img {
  width: 72px;
  height: 72px;
  margin: 0 auto 16px;
  object-fit: contain;
}

.data-card h3 {
  font-size: 32px;
  font-weight: 700;
  color: #1a2333;
  margin-bottom: 6px;
}

.data-card p {
  font-size: 14px;
  color: var(--muted);
}

/* Partners */
.partner-section {
  position: relative;
  min-height: 360px;
  padding: 80px 24px;
  background: #000 url("../assets/partner-bg.png") center / cover no-repeat;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}

.partner-section .section-title {
  margin-bottom: 40px;
}

.partner-list {
  display: flex;
  gap: 28px;
  flex-wrap: wrap;
  justify-content: center;
}

.partner-item {
  width: 220px;
  height: 88px;
  background: #fff;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px 24px;
}

.partner-item img {
  max-height: 42px;
  max-width: 160px;
  width: auto;
  object-fit: contain;
}

/* Footer */
.footer {
  background: var(--footer) url("../assets/footer-bg.png") center top / cover no-repeat;
  padding: 56px 24px 28px;
  color: rgba(255, 255, 255, 0.78);
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1.6fr 0.8fr;
  gap: 40px;
}

.footer h3 {
  font-size: 18px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 20px;
}

.app-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 10px 24px;
}

.app-grid a {
  font-size: 13px;
  color: rgba(255, 255, 255, 0.65);
  transition: color 0.2s;
}

.app-grid a:hover {
  color: #fff;
}

.contact-block a {
  font-size: 14px;
  color: rgba(255, 255, 255, 0.75);
}

.footer-copy {
  max-width: var(--max);
  margin: 40px auto 0;
  padding-top: 20px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
  font-size: 12px;
  color: rgba(255, 255, 255, 0.45);
  text-align: center;
}

.footer-copy a {
  color: rgba(255, 255, 255, 0.55);
  margin-left: 4px;
}

/* Help modal */
.modal-mask {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 2000;
  background: rgba(0, 0, 0, 0.45);
  align-items: center;
  justify-content: center;
  padding: 24px;
}

.modal-mask.open {
  display: flex;
}

.modal {
  width: 100%;
  max-width: 480px;
  background: #fff;
  color: var(--text);
  border-radius: 10px;
  padding: 28px 28px 24px;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.25);
}

.modal h3 {
  font-size: 18px;
  margin-bottom: 16px;
  color: #242833;
}

.modal p {
  font-size: 14px;
  margin-bottom: 10px;
  line-height: 1.7;
}

.modal .hotline {
  margin-top: 8px;
  color: var(--blue);
}

.modal-actions {
  margin-top: 20px;
  text-align: right;
}

.modal-actions a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 18px;
  border-radius: 4px;
  background: var(--blue);
  color: #fff;
  font-size: 14px;
}

/* Responsive */
@media (max-width: 1100px) {
  .feature-grid.cols-5 {
    grid-template-columns: repeat(3, 1fr);
  }

  .feature-grid.cols-4 {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .side-nav {
    display: none;
  }

  .hero-content {
    padding: 0 24px;
  }

  .feature-grid.cols-5,
  .feature-grid.cols-4,
  .feature-grid.cols-3 {
    grid-template-columns: 1fr;
  }

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

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

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

  .header-right .divider {
    margin: 0 10px;
  }
}