:root {
  --background: #f6f7f9;
  --surface: #ffffff;
  --surface-muted: #eef4f1;
  --text: #17212b;
  --muted: #5e6a75;
  --line: #dbe2e8;
  --primary: #256f6c;
  --primary-dark: #164b4a;
  --accent: #d79b30;
  --blue: #456fb7;
  --shadow: 0 18px 45px rgba(25, 38, 52, 0.12);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background: var(--background);
  color: var(--text);
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 16px clamp(20px, 5vw, 72px);
  background: rgba(246, 247, 249, 0.92);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 750;
}

.brand-mark {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  background: var(--primary);
  border-radius: 8px;
  color: #ffffff;
  font-size: 13px;
  letter-spacing: 0;
}

.site-nav {
  display: flex;
  gap: clamp(14px, 3vw, 30px);
  color: var(--muted);
  font-size: 15px;
}

.site-nav a:hover {
  color: var(--primary-dark);
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(320px, 0.95fr);
  gap: clamp(28px, 6vw, 76px);
  align-items: center;
  min-height: calc(100vh - 68px);
  padding: clamp(48px, 8vw, 96px) clamp(20px, 5vw, 72px);
}

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

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary);
  font-size: 13px;
  font-weight: 760;
  letter-spacing: 0;
  text-transform: uppercase;
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin-bottom: 22px;
  font-size: clamp(40px, 7vw, 76px);
  line-height: 1.06;
  letter-spacing: 0;
}

h2 {
  margin-bottom: 14px;
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.15;
  letter-spacing: 0;
}

h3 {
  margin-bottom: 10px;
  font-size: 20px;
  line-height: 1.25;
  letter-spacing: 0;
}

.hero-copy,
.section-copy {
  max-width: 640px;
  color: var(--muted);
  font-size: 18px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 30px;
}

.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 8px;
  font-weight: 700;
}

.button-primary {
  background: var(--primary);
  color: #ffffff;
}

.button-secondary {
  background: transparent;
  border-color: var(--line);
  color: var(--primary-dark);
}

.workflow-panel {
  width: min(100%, 560px);
  padding: 20px;
  background: #18242e;
  border: 1px solid #2e3f4d;
  border-radius: 8px;
  box-shadow: var(--shadow);
  color: #eaf0f3;
}

.panel-top {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-bottom: 18px;
  border-bottom: 1px solid #334757;
  color: #b8c4ce;
  font-size: 14px;
}

.status-dot {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #5ed19a;
}

.workflow-list {
  display: grid;
  gap: 14px;
  padding: 18px 0 0;
  margin: 0;
  list-style: none;
}

.workflow-list li {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 14px;
  padding: 16px;
  background: #22313d;
  border: 1px solid #344958;
  border-radius: 8px;
}

.step-number {
  color: #f0b353;
  font-weight: 800;
}

.workflow-list strong {
  display: block;
  margin-bottom: 4px;
}

.workflow-list p {
  margin-bottom: 0;
  color: #b8c4ce;
  font-size: 14px;
}

.section {
  padding: clamp(52px, 8vw, 96px) clamp(20px, 5vw, 72px);
  border-top: 1px solid var(--line);
}

.section-heading {
  max-width: 720px;
  margin-bottom: 28px;
}

.feature-grid,
.structure-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 16px;
}

.feature-card,
.structure-grid article {
  min-height: 190px;
  padding: 22px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.feature-card p,
.structure-grid p {
  margin-bottom: 0;
  color: var(--muted);
}

.service-badge {
  display: grid;
  width: 42px;
  height: 42px;
  margin-bottom: 18px;
  place-items: center;
  border-radius: 8px;
  color: #ffffff;
  font-weight: 800;
}

.bilibili {
  background: var(--blue);
}

.v2ex {
  background: var(--primary);
}

.railgun {
  background: var(--accent);
}

.telegram {
  background: #3d566e;
}

.split-section {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(320px, 1fr);
  gap: clamp(28px, 6vw, 72px);
  align-items: start;
  background: var(--surface-muted);
}

.steps {
  display: grid;
  gap: 12px;
}

.step {
  display: grid;
  grid-template-columns: 42px 1fr;
  gap: 14px;
  align-items: start;
  padding: 18px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 8px;
}

.step span {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 8px;
  background: var(--primary);
  color: #ffffff;
  font-weight: 800;
}

.step p {
  margin-bottom: 0;
  color: var(--muted);
}

.site-footer {
  padding: 28px clamp(20px, 5vw, 72px);
  border-top: 1px solid var(--line);
  color: var(--muted);
}

.site-footer p {
  margin-bottom: 0;
}

@media (max-width: 980px) {
  .hero,
  .split-section {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: auto;
  }

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

@media (max-width: 640px) {
  .site-header {
    position: static;
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
  }

  .site-nav {
    width: 100%;
    justify-content: space-between;
  }

  h1 {
    font-size: 38px;
  }

  .button,
  .hero-actions {
    width: 100%;
  }

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

  .workflow-panel {
    padding: 14px;
  }

  .workflow-list li,
  .step {
    grid-template-columns: 1fr;
  }
}