:root {
  color-scheme: light;
  --ink: #101820;
  --muted: #687789;
  --line: rgba(16, 24, 32, 0.11);
  --blue: #5bb7ff;
  --blue-deep: #0877d9;
  --blue-soft: #eaf7ff;
  --green: #86d9c5;
  --surface: rgba(255, 255, 255, 0.76);
  --shadow: 0 22px 70px rgba(20, 48, 76, 0.14);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 12% 14%, rgba(91, 183, 255, 0.16), transparent 28rem),
    linear-gradient(180deg, #f7fbff 0%, #ffffff 38%, #f8fbfd 100%);
  color: var(--ink);
}

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

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

.site-header {
  position: fixed;
  z-index: 20;
  top: 0;
  left: 0;
  right: 0;
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 24px;
  height: 64px;
  padding: 0 clamp(18px, 4vw, 52px);
  background: rgba(247, 251, 255, 0.72);
  border-bottom: 1px solid transparent;
  backdrop-filter: saturate(180%) blur(22px);
  transition: border-color 240ms ease, background 240ms ease;
}

.site-header.is-elevated {
  background: rgba(247, 251, 255, 0.9);
  border-color: var(--line);
}

.brand img {
  width: 168px;
  height: 40px;
}

.nav {
  display: flex;
  gap: clamp(18px, 3vw, 36px);
  color: rgba(16, 24, 32, 0.68);
  font-size: 14px;
}

.nav a,
.lang-toggle {
  transition: color 180ms ease;
}

.nav a:hover,
.lang-toggle:hover {
  color: var(--ink);
}

.header-actions {
  justify-self: end;
  display: flex;
  align-items: center;
  gap: 10px;
}

.lang-toggle {
  width: 42px;
  height: 34px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.62);
  color: var(--muted);
  cursor: pointer;
  font: inherit;
  font-size: 13px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border: 1px solid rgba(8, 119, 217, 0.12);
  border-radius: 999px;
  background: linear-gradient(135deg, var(--blue-deep), var(--blue));
  color: #fff;
  font-size: 15px;
  font-weight: 650;
  box-shadow: 0 12px 30px rgba(8, 119, 217, 0.2);
  transition: transform 180ms ease, box-shadow 180ms ease;
}

.button:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 36px rgba(8, 119, 217, 0.24);
}

.button.small {
  min-height: 34px;
  padding: 0 15px;
  font-size: 13px;
}

.button.ghost {
  background: rgba(255, 255, 255, 0.72);
  color: var(--blue-deep);
  box-shadow: none;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(340px, 1.08fr);
  align-items: center;
  gap: clamp(32px, 6vw, 80px);
  min-height: 100svh;
  padding: 112px clamp(22px, 6vw, 86px) 56px;
}

.hero-copy {
  max-width: 690px;
}

.eyebrow {
  margin: 0 0 18px;
  color: var(--blue-deep);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0;
}

h1,
h2,
h3,
p {
  overflow-wrap: anywhere;
}

h1 {
  margin: 0;
  max-width: 760px;
  font-size: clamp(48px, 7.4vw, 104px);
  line-height: 0.98;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: clamp(34px, 5vw, 68px);
  line-height: 1.04;
  letter-spacing: 0;
}

h3 {
  margin: 0;
  font-size: 22px;
  line-height: 1.2;
  letter-spacing: 0;
}

.hero-text {
  max-width: 620px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(18px, 2vw, 24px);
  line-height: 1.55;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 34px;
}

.hero-visual {
  position: relative;
  min-height: 640px;
  border-radius: 32px;
  overflow: hidden;
  box-shadow: var(--shadow);
  isolation: isolate;
}

.hero-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.04), rgba(11, 55, 89, 0.24));
  z-index: 1;
}

.hero-visual img,
.split-media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.glass-panel {
  position: absolute;
  z-index: 2;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 22px;
  background: rgba(255, 255, 255, 0.72);
  box-shadow: 0 18px 44px rgba(10, 38, 64, 0.16);
  backdrop-filter: blur(22px);
}

.panel-main {
  left: 26px;
  bottom: 28px;
  display: grid;
  gap: 6px;
  width: min(260px, calc(100% - 52px));
  padding: 22px;
}

.panel-main span,
.panel-secondary span {
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
}

.panel-main strong {
  font-size: 54px;
  line-height: 1;
}

.panel-main small {
  color: var(--blue-deep);
  font-size: 14px;
}

.panel-secondary {
  right: 22px;
  top: 24px;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 18px 20px;
}

.signal-bars {
  display: flex;
  align-items: end;
  gap: 5px;
  height: 34px;
}

.signal-bars i {
  display: block;
  width: 7px;
  border-radius: 999px;
  background: linear-gradient(180deg, var(--green), var(--blue));
  animation: pulseBar 1.8s ease-in-out infinite;
}

.signal-bars i:nth-child(1) { height: 14px; }
.signal-bars i:nth-child(2) { height: 22px; animation-delay: 120ms; }
.signal-bars i:nth-child(3) { height: 30px; animation-delay: 240ms; }
.signal-bars i:nth-child(4) { height: 18px; animation-delay: 360ms; }

.section {
  padding: clamp(76px, 11vw, 140px) clamp(22px, 6vw, 86px);
}

.intro {
  padding-top: 36px;
  text-align: center;
}

.intro p {
  max-width: 980px;
  margin: 0 auto;
  font-size: clamp(28px, 4.8vw, 58px);
  font-weight: 720;
  line-height: 1.12;
  letter-spacing: 0;
}

.section-heading {
  max-width: 780px;
  margin: 0 auto 42px;
  text-align: center;
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 18px;
}

.feature-card {
  min-height: 292px;
  padding: 34px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.66);
  box-shadow: 0 12px 42px rgba(20, 48, 76, 0.07);
}

.feature-card p,
.split-copy p,
.contact-section p {
  color: var(--muted);
  font-size: 18px;
  line-height: 1.7;
}

.icon-dot {
  display: block;
  width: 42px;
  height: 42px;
  margin-bottom: 32px;
  border-radius: 50%;
  background:
    radial-gradient(circle at 34% 30%, #fff 0 13%, transparent 14%),
    linear-gradient(135deg, var(--blue), var(--green));
}

.split-section {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(32px, 6vw, 76px);
  align-items: center;
  padding: clamp(72px, 10vw, 132px) clamp(22px, 6vw, 86px);
  background: #f3f9fd;
}

.split-media {
  height: min(66vw, 620px);
  min-height: 420px;
  overflow: hidden;
  border-radius: 28px;
  box-shadow: var(--shadow);
}

.split-copy {
  max-width: 620px;
}

.institution-band {
  padding: clamp(80px, 12vw, 150px) clamp(22px, 6vw, 86px);
  background:
    linear-gradient(135deg, rgba(235, 248, 255, 0.95), rgba(255, 255, 255, 0.94)),
    #fff;
}

.metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px;
  max-width: 980px;
  margin: 0 auto;
}

.metrics div {
  display: grid;
  gap: 8px;
  min-height: 174px;
  align-content: center;
  padding: 28px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.74);
  text-align: center;
}

.metrics strong {
  font-size: clamp(44px, 6vw, 76px);
  line-height: 1;
}

.metrics span {
  color: var(--muted);
  font-weight: 650;
}

.contact-section {
  display: grid;
  justify-items: center;
  padding: clamp(82px, 12vw, 152px) clamp(22px, 6vw, 86px);
  text-align: center;
}

.contact-section h2,
.contact-section p {
  max-width: 820px;
}

.contact-section p {
  margin: 24px auto 32px;
}

.site-footer {
  display: flex;
  justify-content: space-between;
  gap: 18px;
  padding: 28px clamp(22px, 6vw, 86px);
  border-top: 1px solid var(--line);
  color: var(--muted);
  font-size: 13px;
}

.reveal {
  opacity: 0;
  transform: translateY(22px);
  transition: opacity 700ms ease, transform 700ms ease;
}

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

@keyframes pulseBar {
  0%, 100% { transform: scaleY(0.74); opacity: 0.72; }
  50% { transform: scaleY(1); opacity: 1; }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}

@media (max-width: 900px) {
  .site-header {
    grid-template-columns: 1fr auto;
  }

  .nav {
    display: none;
  }

  .hero,
  .split-section {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 104px;
  }

  .hero-visual {
    min-height: 520px;
  }

  .feature-grid,
  .metrics {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 560px) {
  .site-header {
    height: 58px;
    padding: 0 14px;
  }

  .brand img {
    width: 132px;
  }

  .button.small {
    display: none;
  }

  .hero {
    padding-left: 18px;
    padding-right: 18px;
  }

  h1 {
    font-size: 48px;
  }

  .hero-visual {
    min-height: 430px;
    border-radius: 24px;
  }

  .panel-secondary {
    left: 16px;
    right: auto;
    top: 16px;
  }

  .panel-main {
    left: 16px;
    bottom: 16px;
    width: calc(100% - 32px);
  }

  .feature-card {
    min-height: auto;
    padding: 28px;
  }

  .split-media {
    min-height: 340px;
  }

  .site-footer {
    flex-direction: column;
  }
}