:root {
  color-scheme: light;
  --primary: #0b57d0;
  --on-primary: #ffffff;
  --primary-container: #d7e3ff;
  --secondary: #565f71;
  --tertiary: #705575;
  --surface: #fbfcff;
  --surface-container: #eef3fb;
  --surface-container-high: #e5ebf5;
  --outline: #727782;
  --text: #191c20;
  --muted: #42474f;
  --success: #146c2e;
  --warning: #7a5900;
  --shadow: 0 24px 60px rgba(11, 87, 208, 0.16);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-width: 320px;
  background: var(--surface);
  color: var(--text);
  font-family:
    Inter, Roboto, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    sans-serif;
  line-height: 1.6;
}

a {
  color: inherit;
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(20px, 5vw, 72px);
  background: rgba(251, 252, 255, 0.68);
  border-bottom: 1px solid rgba(114, 119, 130, 0.18);
  box-shadow: 0 12px 36px rgba(11, 87, 208, 0.08);
  -webkit-backdrop-filter: blur(22px) saturate(160%);
  backdrop-filter: blur(22px) saturate(160%);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 800;
  text-decoration: none;
}

.brand img {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.nav {
  display: flex;
  align-items: center;
  gap: 6px;
}

.nav a {
  min-height: 40px;
  padding: 8px 14px;
  border-radius: 20px;
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 650;
  text-decoration: none;
}

.nav a:hover {
  background: var(--surface-container);
  color: var(--primary);
}

/* 立即尝试 CTA button in nav */
.nav-cta {
  background: var(--primary) !important;
  color: var(--on-primary) !important;
  margin-left: 8px;
  font-weight: 800 !important;
  box-shadow: 0 4px 14px rgba(11, 87, 208, 0.28);
  transition: transform 160ms ease, box-shadow 160ms ease, background 160ms ease;
}

.nav-cta:hover {
  background: #0a4eb8 !important;
  color: var(--on-primary) !important;
  transform: translateY(-1px);
  box-shadow: 0 8px 20px rgba(11, 87, 208, 0.34);
}

/* Hamburger menu button — hidden on desktop */
.hamburger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border: none;
  border-radius: 10px;
  background: transparent;
  cursor: pointer;
  z-index: 20;
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2.5px;
  border-radius: 2px;
  background: var(--text);
  transition: transform 200ms ease, opacity 200ms ease;
}

.hamburger[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7.5px) rotate(45deg);
}

.hamburger[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}

.hamburger[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7.5px) rotate(-45deg);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: clamp(28px, 6vw, 84px);
  align-items: center;
  min-height: calc(100vh - 68px);
  padding: clamp(48px, 7vw, 96px) clamp(20px, 5vw, 72px);
}

.hero-copy {
  max-width: 680px;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 0.85rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

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

h1 {
  margin: 0;
  color: var(--text);
  font-size: clamp(3.5rem, 11vw, 8rem);
  line-height: 0.9;
  letter-spacing: 0;
}

h2 {
  margin: 0;
  font-size: clamp(2rem, 4vw, 3.5rem);
  line-height: 1.05;
  letter-spacing: 0;
}

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

.lead {
  max-width: 620px;
  margin: 28px 0 0;
  color: var(--muted);
  font-size: clamp(1.1rem, 2vw, 1.35rem);
}

.actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.button,
.download-link {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 48px;
  padding: 12px 22px;
  border-radius: 24px;
  font-weight: 800;
  text-decoration: none;
  transition:
    transform 160ms ease,
    box-shadow 160ms ease,
    background 160ms ease;
}

.button:hover,
.download-link:hover {
  transform: translateY(-1px);
}

.primary {
  background: var(--primary);
  color: var(--on-primary);
  box-shadow: 0 10px 24px rgba(11, 87, 208, 0.22);
}

.secondary {
  background: var(--primary-container);
  color: #001b3f;
}

.hero-panel {
  display: flex;
  justify-content: center;
}

.device-window {
  width: min(100%, 560px);
  overflow: hidden;
  border: 1px solid rgba(114, 119, 130, 0.32);
  border-radius: 28px;
  background: var(--surface-container);
  box-shadow: var(--shadow);
}

.window-bar {
  display: flex;
  gap: 8px;
  padding: 16px 18px;
  border-bottom: 1px solid rgba(114, 119, 130, 0.24);
}

.window-bar span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--outline);
}

.window-bar span:first-child {
  background: #ba1a1a;
}

.window-bar span:nth-child(2) {
  background: #a46700;
}

.window-bar span:nth-child(3) {
  background: #146c2e;
}

.stream-preview {
  position: relative;
  display: grid;
  min-height: 280px;
  place-items: center;
  background:
    linear-gradient(135deg, rgba(11, 87, 208, 0.94), rgba(112, 85, 117, 0.9)),
    radial-gradient(circle at 30% 30%, #d7e3ff, transparent 32%);
}

.live-badge {
  position: absolute;
  top: 18px;
  left: 18px;
  padding: 6px 12px;
  border-radius: 16px;
  background: #ba1a1a;
  color: #ffffff;
  font-size: 0.8rem;
  font-weight: 900;
}

.play-symbol {
  width: 86px;
  height: 86px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.88);
  clip-path: polygon(28% 18%, 28% 82%, 82% 50%);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  background: rgba(114, 119, 130, 0.24);
}

.stats-grid div {
  min-width: 0;
  padding: 18px 14px;
  background: var(--surface);
}

.stats-grid strong,
.stats-grid span {
  display: block;
}

.stats-grid strong {
  color: var(--primary);
  font-size: 1.02rem;
}

.stats-grid span {
  color: var(--muted);
  font-size: 0.88rem;
}

.section {
  padding: clamp(64px, 8vw, 112px) clamp(20px, 5vw, 72px);
}

.section-heading {
  max-width: 820px;
  margin-bottom: 32px;
}

.section-heading p:not(.eyebrow) {
  max-width: 760px;
  color: var(--muted);
  font-size: 1.06rem;
}

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

.architecture-card,
.download-card {
  min-width: 0;
  padding: 24px;
  border: 1px solid rgba(114, 119, 130, 0.24);
  border-radius: 24px;
  background: var(--surface-container);
}

.architecture-card .icon {
  display: grid;
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
  place-items: center;
  border-radius: 16px;
  background: var(--primary);
  color: var(--on-primary);
  font-weight: 900;
}

.architecture-card p,
.download-card p,
.feature-item p,
.source-section p {
  color: var(--muted);
}

.feature-band {
  background: var(--surface-container);
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  overflow: hidden;
  border: 1px solid rgba(114, 119, 130, 0.24);
  border-radius: 28px;
  background: rgba(114, 119, 130, 0.24);
}

.feature-item {
  min-width: 0;
  padding: 28px;
  background: var(--surface);
}

.download-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.download-card {
  display: flex;
  min-height: 240px;
  flex-direction: column;
  align-items: flex-start;
}

.status {
  margin-bottom: 18px;
  padding: 5px 10px;
  border-radius: 14px;
  background: rgba(20, 108, 46, 0.12);
  color: var(--success);
  font-size: 0.78rem;
  font-weight: 850;
}

.status.muted {
  background: rgba(122, 89, 0, 0.12);
  color: var(--warning);
}

.download-link {
  margin-top: auto;
  background: var(--primary);
  color: var(--on-primary);
}

.planned {
  background: var(--surface-container-high);
}

.source-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  background: #001b3f;
  color: #ffffff;
}

.source-section .eyebrow,
.source-section p {
  color: #d7e3ff;
}

.source-section div {
  max-width: 820px;
}

.footer {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  padding: 28px clamp(20px, 5vw, 72px);
  background: #001533;
  color: #d7e3ff;
  font-size: 0.92rem;
}

.footer span:nth-child(2) {
  text-align: center;
}

.footer span:last-child {
  text-align: right;
}

@media (max-width: 900px) {
  .topbar {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
  }

  .hamburger {
    display: flex;
  }

  .nav {
    display: none;
    width: 100%;
    flex-direction: column;
    gap: 2px;
    padding: 8px 0 4px;
    border-top: 1px solid rgba(114, 119, 130, 0.14);
    margin-top: 10px;
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    width: 100%;
    padding: 12px 16px;
    border-radius: 14px;
    font-size: 1rem;
  }

  .nav-cta {
    margin-left: 0 !important;
    margin-top: 6px;
    text-align: center;
  }

  .hero {
    grid-template-columns: 1fr;
    min-height: auto;
  }

  .architecture-grid,
  .download-grid {
    grid-template-columns: 1fr 1fr;
  }

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

  .source-section {
    align-items: flex-start;
    flex-direction: column;
  }
}

@media (max-width: 640px) {
  .topbar {
    padding: 10px 16px;
  }

  .hero,
  .section {
    padding-right: 16px;
    padding-left: 16px;
  }

  .hero {
    padding-top: 32px;
    padding-bottom: 32px;
    gap: 24px;
  }

  h1 {
    font-size: clamp(2.8rem, 10vw, 4rem);
  }

  h2 {
    font-size: clamp(1.6rem, 5vw, 2.4rem);
  }

  .lead {
    font-size: 1rem;
    margin-top: 16px;
  }

  .hero-panel {
    width: 100%;
  }

  .device-window {
    width: 100%;
    border-radius: 20px;
  }

  .stream-preview {
    min-height: 180px;
  }

  .play-symbol {
    width: 60px;
    height: 60px;
  }

  .architecture-grid,
  .download-grid,
  .feature-list {
    grid-template-columns: 1fr;
  }

  .architecture-card,
  .download-card {
    padding: 20px;
    border-radius: 18px;
  }

  .feature-item {
    padding: 20px;
  }

  .actions {
    flex-direction: column;
  }

  .button,
  .download-link {
    width: 100%;
    justify-content: center;
  }

  .nav a {
    min-height: 48px;
    padding: 14px 16px;
    font-size: 1.05rem;
  }

  .nav-cta {
    min-height: 50px;
    font-size: 1.05rem;
  }

  .footer {
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 24px 16px;
  }

  .footer span,
  .footer span:last-child {
    text-align: left;
  }
}