:root {
  --bg: #fcfbf8;
  --surface: rgba(255, 255, 255, 0.94);
  --surface-strong: #ffffff;
  --surface-muted: #f3efe5;
  --line: rgba(17, 17, 17, 0.08);
  --text-main: #111111;
  --text-muted: #68645d;
  --accent: #b89655;
  --accent-soft: rgba(184, 150, 85, 0.07);
  --accent-strong: #8b6a2f;
  --shadow-sm: 0 10px 30px rgba(17, 17, 17, 0.05);
  --shadow-lg: 0 24px 70px rgba(17, 17, 17, 0.08);
  --radius-sm: 16px;
  --radius-md: 24px;
  --radius-lg: 36px;
  --container: 1180px;
  --font-heading: "Iowan Old Style", "Palatino Linotype", "Noto Serif SC", Georgia, serif;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: Inter, "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text-main);
  background:
    radial-gradient(circle at top right, rgba(17, 17, 17, 0.04), transparent 24%),
    var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
}

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

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

button {
  font: inherit;
}

.section-container {
  width: min(calc(100% - 32px), var(--container));
  margin: 0 auto;
}

.navbar {
  position: sticky;
  top: 0;
  z-index: 50;
  backdrop-filter: blur(18px);
  background: rgba(252, 251, 248, 0.78);
  border-bottom: 1px solid transparent;
  transition: background 0.25s ease, border-color 0.25s ease, box-shadow 0.25s ease;
}

.navbar.scrolled {
  background: rgba(255, 255, 255, 0.92);
  border-color: var(--line);
  box-shadow: 0 8px 30px rgba(17, 17, 17, 0.04);
}

.nav-container {
  width: min(calc(100% - 64px), 1120px);
  margin: 0 auto;
  min-height: 76px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
}

.brand,
.footer-brand {
  display: flex;
  align-items: center;
  gap: 14px;
}

.brand-logo,
.footer-logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  box-shadow: 0 8px 18px rgba(17, 17, 17, 0.08);
}

.brand-text {
  font-size: 1.05rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 4px;
}

.nav-link {
  padding: 10px 16px;
  border-radius: 999px;
  color: var(--text-muted);
  transition: color 0.2s ease, background 0.2s ease;
}

.nav-link:hover {
  background: rgba(255, 255, 255, 0.8);
  color: var(--text-main);
}

.btn-primary {
  background: #111111;
  color: #fff;
  box-shadow: 0 10px 24px rgba(17, 17, 17, 0.14);
}

.btn-primary:hover {
  color: #fff;
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  padding: 8px;
  border: 0;
  background: transparent;
}

.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  margin: 4px 0;
  background: var(--text-main);
  border-radius: 999px;
  transition: transform 0.2s ease, opacity 0.2s ease;
}

.hero,
.features,
.preview,
.workflow,
.architecture,
.start {
  padding: 96px 0;
}

.hero {
  padding-top: 64px;
  position: relative;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 0.96fr) minmax(0, 1.04fr);
  gap: 56px;
  align-items: start;
}

.hero-copy {
  padding-top: 18px;
}

.hero-scroll-cue {
  position: absolute;
  left: 50%;
  bottom: 44px;
  transform: translateX(-50%);
  display: inline-flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  color: var(--text-muted);
  opacity: 0.82;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.hero-scroll-cue:hover {
  opacity: 1;
  transform: translateX(-50%) translateY(-2px);
}

.hero-scroll-mouse {
  position: relative;
  width: 24px;
  height: 38px;
  border: 1px solid rgba(17, 17, 17, 0.18);
  border-radius: 999px;
}

.hero-scroll-wheel {
  position: absolute;
  top: 8px;
  left: 50%;
  width: 4px;
  height: 8px;
  margin-left: -2px;
  border-radius: 999px;
  background: rgba(17, 17, 17, 0.5);
  animation: heroScrollWheel 1.8s ease-in-out infinite;
}

.hero-scroll-text {
  font-size: 0.82rem;
  letter-spacing: 0.08em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  margin-bottom: 22px;
  border: 1px solid rgba(184, 150, 85, 0.16);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: var(--accent-strong);
  font-size: 0.92rem;
  font-weight: 600;
  letter-spacing: 0.03em;
}

.hero h1,
.section-heading h2,
.start-card h2 {
  margin: 0;
  font-family: var(--font-heading);
  line-height: 1.08;
  letter-spacing: -0.03em;
}

.hero h1 {
  max-width: 11ch;
  font-size: clamp(2.35rem, 5.2vw, 4.4rem);
}

.hero h1 span {
  display: block;
  color: var(--text-main);
}

.hero-description,
.section-heading p,
.start-card p,
.feature-card p,
.preview-copy p,
.timeline-item p,
.stack-card span,
.footer-brand p {
  color: var(--text-muted);
}

.hero-description {
  max-width: 54ch;
  margin: 24px 0 0;
  font-size: 1.05rem;
}

.hero-highlights {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  padding: 0;
  margin: 24px 0 0;
  list-style: none;
}

.hero-highlights li {
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.82);
  border: 1px solid rgba(17, 17, 17, 0.08);
  color: var(--text-muted);
  font-size: 0.94rem;
}

.hero-actions,
.start-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 32px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 22px;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  transition: transform 0.2s ease, border-color 0.2s ease, background 0.2s ease;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.8);
  border-color: var(--line);
}

.btn-secondary:hover {
  background: #fff;
  border-color: rgba(17, 17, 17, 0.18);
  transform: translateY(-1px);
}

.feature-card,
.preview-shell,
.timeline-item,
.stack-card,
.start-card,
.hero-window {
  border: 1px solid var(--line);
  background: var(--surface);
  box-shadow: var(--shadow-sm);
}

.feature-card,
.stack-card,
.timeline-item {
  padding: 22px;
  border-radius: var(--radius-md);
}

.hero-window {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 28px 70px rgba(17, 17, 17, 0.1);
}

.window-bar {
  display: flex;
  gap: 8px;
  padding: 18px 20px;
  border-bottom: 1px solid var(--line);
}

.window-bar span {
  width: 10px;
  height: 10px;
  border-radius: 999px;
  background: #ddd6c8;
}

.window-body {
  display: grid;
  grid-template-columns: 180px 1fr;
  gap: 22px;
  padding: 22px;
}

.window-sidebar {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.sidebar-pill {
  padding: 11px 14px;
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--line);
  color: var(--text-muted);
}

.sidebar-pill.active {
  background: var(--accent-soft);
  color: var(--text-main);
  border-color: rgba(184, 150, 85, 0.12);
}

.window-panel {
  display: grid;
  gap: 18px;
}

.code-block {
  display: grid;
  gap: 10px;
  padding: 18px;
  border-radius: var(--radius-md);
  background: #151515;
  color: rgba(255, 255, 255, 0.8);
  font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}

.preview-card {
  overflow: hidden;
  border-radius: calc(var(--radius-lg) - 8px);
  border: 1px solid rgba(17, 17, 17, 0.08);
}

.preview-card img {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  object-position: top center;
}

.window-footer {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 12px;
}

.window-metric {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.92);
  border: 1px solid rgba(17, 17, 17, 0.08);
}

.window-metric strong {
  display: block;
  font-size: 0.95rem;
}

.window-metric span {
  display: block;
  margin-top: 4px;
  color: var(--text-muted);
  font-size: 0.86rem;
}

.section-heading {
  max-width: 760px;
  margin-bottom: 44px;
}

.section-heading h2 {
  font-size: clamp(2rem, 4vw, 3.5rem);
}

.section-heading p {
  margin: 18px 0 0;
  font-size: 1.02rem;
}

.feature-grid,
.architecture-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 20px;
}

.features,
.architecture {
  background: transparent;
}

.feature-card,
.stack-card {
  padding: 30px;
  border-radius: var(--radius-md);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.feature-card:hover,
.stack-card:hover,
.timeline-item:hover {
  transform: translateY(-2px);
  box-shadow: 0 18px 40px rgba(17, 17, 17, 0.06);
}

.feature-card-wide {
  grid-column: span 2;
  display: grid;
  grid-template-columns: 88px 1fr;
  gap: 18px;
}

.feature-card h3,
.stack-card h3,
.preview-copy h3,
.timeline-item h3 {
  margin: 0 0 10px;
  font-size: 1.18rem;
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 60px;
  height: 60px;
  border-radius: 18px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-weight: 800;
}

.feature-card ul {
  padding-left: 18px;
  margin: 16px 0 0;
  color: var(--text-muted);
}

.feature-card li + li {
  margin-top: 6px;
}

.preview-shell {
  padding: 28px;
  border-radius: var(--radius-lg);
  background: rgba(255, 255, 255, 0.96);
}

.preview-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 22px;
}

.preview-tab {
  padding: 12px 18px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.8);
  color: var(--text-muted);
  cursor: pointer;
}

.preview-tab.active {
  background: #111111;
  border-color: transparent;
  color: #fff;
}

.preview-panel {
  display: none;
  grid-template-columns: minmax(0, 1.4fr) minmax(280px, 0.8fr);
  gap: 24px;
  align-items: center;
}

.preview-panel.active {
  display: grid;
}

.preview-panel img {
  width: 100%;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: #fff;
}

.timeline {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.timeline-item {
  display: grid;
  gap: 16px;
  padding: 24px;
  border-radius: var(--radius-md);
  transition: transform 0.22s ease, box-shadow 0.22s ease, border-color 0.22s ease;
}

.timeline-step {
  display: inline-flex;
  width: 42px;
  height: 42px;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
  background: #111111;
  color: #fff;
  font-weight: 700;
  flex: 0 0 auto;
}

.stack-card p {
  margin: 0;
  font-weight: 700;
  color: var(--text-main);
}

.stack-card span {
  display: block;
  margin-top: 12px;
}

.architecture-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.start-card {
  display: grid;
  grid-template-columns: minmax(0, 0.92fr) minmax(0, 1.08fr);
  gap: 32px;
  align-items: start;
  padding: 40px;
  border-radius: var(--radius-lg);
  background: var(--surface-strong);
  box-shadow: var(--shadow-lg);
}

.download-panel {
  display: grid;
  gap: 8px;
  padding: 22px;
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.94);
  border: 1px solid rgba(17, 17, 17, 0.08);
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.download-btn {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 18px 20px;
  border-radius: 22px;
  border: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.88);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.download-btn:hover {
  transform: translateY(-2px);
  border-color: rgba(184, 150, 85, 0.16);
  box-shadow: 0 18px 40px rgba(17, 17, 17, 0.08);
}

.download-btn-primary {
  background: #111111;
  color: #fff;
  border-color: transparent;
}

.download-btn-primary .download-label,
.download-btn-primary .download-meta {
  color: rgba(255, 255, 255, 0.78);
}

.download-label {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.download-os {
  font-size: 1.2rem;
  font-weight: 700;
}

.download-meta {
  font-size: 0.92rem;
  color: var(--text-muted);
}

.download-links {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 24px;
  padding-top: 18px;
  border-top: 1px solid rgba(17, 17, 17, 0.08);
  color: var(--text-muted);
}

.download-links a {
  transition: color 0.2s ease;
}

.download-links a:hover {
  color: var(--accent-strong);
}

.download-note {
  display: inline-flex;
  margin-top: 18px;
  padding: 10px 14px;
  border-radius: 999px;
  background: rgba(184, 150, 85, 0.08);
  color: var(--accent-strong);
  font-size: 0.92rem;
  font-weight: 600;
}

.footer {
  padding: 0 0 42px;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding-top: 24px;
  border-top: 1px solid var(--line);
}

.footer-brand {
  align-items: flex-start;
  gap: 14px;
}

.footer-logo {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  flex: 0 0 auto;
}

.footer-brand-copy {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.footer-brand-copy strong {
  display: block;
  font-size: 1rem;
  line-height: 1;
}

.footer-brand-copy p {
  margin: 0;
  line-height: 1.1;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  color: var(--text-muted);
}

.footer-meta {
  padding-top: 14px;
  color: var(--text-muted);
  font-size: 0.9rem;
  text-align: center;
}

.footer-meta p {
  margin: 0;
}

.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

@keyframes heroScrollWheel {
  0%,
  100% {
    opacity: 0.4;
    transform: translateY(0);
  }

  50% {
    opacity: 1;
    transform: translateY(8px);
  }
}

@media (max-width: 1024px) {
  .hero-grid,
  .start-card,
  .preview-panel,
  .window-body {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .architecture-grid,
  .timeline,
  .download-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .feature-card-wide {
    grid-column: span 2;
  }

  .window-sidebar {
    flex-direction: row;
    flex-wrap: wrap;
  }

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

@media (max-width: 760px) {
  .nav-toggle {
    display: inline-block;
  }

  .nav-menu {
    position: absolute;
    top: 76px;
    left: 16px;
    right: 16px;
    display: none;
    flex-direction: column;
    align-items: stretch;
    padding: 14px;
    border-radius: 20px;
    border: 1px solid var(--line);
    background: rgba(255, 255, 255, 0.98);
    box-shadow: var(--shadow-sm);
  }

  .nav-menu.open {
    display: flex;
  }

  .hero,
  .features,
  .preview,
  .workflow,
  .architecture,
  .start {
    padding: 76px 0;
  }

  .hero h1 {
    max-width: none;
    font-size: clamp(2.2rem, 12vw, 3.3rem);
  }

  .hero-scroll-cue {
    bottom: 30px;
  }

  .feature-grid,
  .architecture-grid,
  .timeline,
  .footer-inner {
    grid-template-columns: 1fr;
    display: grid;
  }

  .feature-card-wide {
    grid-column: auto;
    grid-template-columns: 1fr;
  }

  .preview-shell,
  .start-card {
    padding: 22px;
  }

  .download-panel {
    padding: 18px;
  }

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

  .footer-inner {
    justify-content: stretch;
  }
}