@import url("https://fonts.googleapis.com/css2?family=Manrope:wght@400;500;600;700;800&family=Noto+Serif+SC:wght@600;700&display=swap");

:root {
  /* 干净墨白 + 克制朱红，少粉少脏 */
  --ink: #121212;
  --ink-soft: #3d3d3d;
  --muted: #6f6f6f;
  --paper: #f7f7f5;
  --paper-2: #ffffff;
  --cinnabar: #b0152a;
  --cinnabar-deep: #6e0f1c;
  --gold: #b8943d;
  --gold-soft: rgba(184, 148, 61, 0.16);
  --line: rgba(18, 18, 18, 0.09);
  --shadow: 0 20px 56px rgba(18, 18, 18, 0.12);
  --radius: 16px;
  --font-sans: "Manrope", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-brand: "Noto Serif SC", "Songti SC", serif;
  --max: 1120px;
}

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

html {
  scroll-behavior: smooth;
}

.hero,
.section,
.cta {
  scroll-margin-top: 84px;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: var(--font-sans);
  background: var(--paper);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

button {
  font: inherit;
  cursor: pointer;
}

.wrap {
  width: min(var(--max), calc(100% - 40px));
  margin-inline: auto;
}

/* —— top bar —— */
.topbar {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  display: flex;
  justify-content: center;
  padding: 16px 20px 0;
  pointer-events: none;
}

.topbar-inner {
  pointer-events: auto;
  width: min(var(--max), 100%);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  min-height: 56px;
  padding: 8px 10px 8px 14px;
  border: 1px solid rgba(255, 255, 255, 0.5);
  border-radius: 14px;
  background: rgba(255, 255, 255, 0.88);
  backdrop-filter: blur(16px);
  box-shadow: 0 10px 28px rgba(18, 18, 18, 0.1);
}

.brand-lockup {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-brand);
  font-weight: 700;
  font-size: 18px;
  letter-spacing: 0.06em;
  line-height: 1;
  flex-shrink: 0;
}

.brand-lockup img {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  object-fit: cover;
  display: block;
  flex-shrink: 0;
}

.top-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  min-height: 40px;
}

.top-nav a:not(.btn) {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 12px;
  border-radius: 10px;
  font-size: 14px;
  line-height: 1;
  color: var(--ink-soft);
  transition: background 180ms ease, color 180ms ease;
}

.top-nav a:not(.btn):hover {
  background: rgba(18, 18, 18, 0.05);
  color: var(--ink);
}

.top-nav .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 36px;
  padding: 0 14px;
  margin-left: 2px;
  line-height: 1;
}

.btn-nav-line {
  background: transparent;
  border-color: rgba(18, 18, 18, 0.14);
  color: var(--ink);
}

.btn-nav-line:hover {
  background: rgba(18, 18, 18, 0.05);
  border-color: rgba(18, 18, 18, 0.28);
  color: var(--ink);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  border: 1px solid transparent;
  border-radius: 12px;
  padding: 12px 20px;
  font-weight: 700;
  transition: transform 170ms ease, background 180ms ease, border-color 180ms ease, color 180ms ease;
}

.btn:active {
  transform: scale(0.99);
}

.btn-primary {
  background: var(--ink);
  color: #fff;
}

.btn-primary:hover {
  background: #2a221e;
}

.btn-ghost {
  background: rgba(255, 255, 255, 0.1);
  border-color: rgba(255, 255, 255, 0.72);
  color: #fff;
  min-height: 48px;
  padding: 12px 22px;
}

.btn-ghost:hover {
  background: rgba(255, 255, 255, 0.18);
  border-color: #fff;
}

.btn-light {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
}

.btn-light:hover {
  background: #f3f3f1;
}

.btn-sm {
  padding: 8px 14px;
  font-size: 13px;
  border-radius: 10px;
}

/* —— hero：左文案 + 右预览 —— */
.hero {
  position: relative;
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  align-items: center;
  padding: 96px 0 48px;
  background: #f4f4f2;
  color: var(--ink);
}

.hero-stage {
  width: min(1200px, calc(100% - 40px));
  margin: 0 auto;
  display: grid;
  grid-template-columns: minmax(280px, 360px) minmax(0, 1fr);
  gap: 36px 40px;
  align-items: center;
}

.hero-copy {
  animation: riseIn 0.65s ease both;
}

.hero-brand {
  margin: 0 0 12px;
  font-family: var(--font-brand);
  font-size: clamp(44px, 5.5vw, 60px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.12em;
  color: var(--ink);
}

.hero-line {
  margin: 0 0 12px;
  font-size: clamp(18px, 2.2vw, 22px);
  font-weight: 700;
  line-height: 1.35;
}

.hero-desc {
  margin: 0 0 24px;
  max-width: 30ch;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.65;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
}

.hero-actions .btn {
  min-height: 44px;
}

.btn-doc {
  background: #fff;
  border-color: var(--line);
  color: var(--ink);
}

.btn-doc:hover {
  background: #ecece8;
  border-color: rgba(18, 18, 18, 0.2);
}

.hero-ui {
  min-width: 0;
  display: flex;
  justify-content: flex-end;
  animation: riseIn 0.7s ease 0.06s both;
  pointer-events: none;
}

.hero-ui .preview-shell {
  width: 100%;
  max-width: 920px;
  border: 1px solid rgba(18, 18, 18, 0.1);
  border-radius: 12px;
  box-shadow: 0 16px 40px rgba(18, 18, 18, 0.1);
  overflow: hidden;
  background: #fff;
}

.preview-shell {
  position: relative;
  width: 100%;
  border-radius: 12px;
  overflow: hidden;
  min-height: 0;
  background: #fff;
}

.preview-scaler {
  position: relative;
  width: 100%;
  height: 100%;
  overflow: hidden;
  background: #fff;
  transform-origin: 0 0;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.preview-shell iframe {
  position: absolute;
  top: 0;
  left: 0;
  border: 0;
  background: #fff;
  overflow: hidden;
  pointer-events: none;
}

@keyframes riseIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* —— sections —— */
.section {
  padding: 96px 0;
}

.section-head {
  max-width: 640px;
  margin-bottom: 40px;
}

.section-kicker {
  margin: 0 0 10px;
  color: var(--gold);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.section-head h2 {
  margin: 0 0 12px;
  font-family: var(--font-brand);
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.2;
  letter-spacing: 0.04em;
}

.section-head p {
  margin: 0;
  color: var(--muted);
  font-size: 16px;
}

.features {
  background: var(--paper-2);
}

.feature-list {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px 36px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.feature-list li {
  padding-top: 20px;
  border-top: 1px solid var(--line);
}

.feature-list h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
}

.feature-list p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* —— flow —— */
.flow-track {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
  counter-reset: step;
}

.flow-item {
  position: relative;
  padding: 8px 0 0;
}

.flow-item::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 12px;
  color: var(--ink);
  font-weight: 800;
  font-size: 13px;
  letter-spacing: 0.12em;
  opacity: 0.35;
}

.flow-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
}

.flow-item p {
  margin: 0;
  color: var(--muted);
  font-size: 14px;
}

/* —— cta —— */
.cta {
  padding: 0 0 96px;
}

.cta-panel {
  position: relative;
  overflow: hidden;
  border-radius: 22px;
  padding: clamp(36px, 6vw, 64px);
  background:
    radial-gradient(circle at 90% 10%, rgba(184, 148, 61, 0.18), transparent 42%),
    linear-gradient(135deg, #1a1214 0%, #3a1520 55%, #161012 100%);
  color: #fff;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: var(--shadow);
}

.cta-panel h2 {
  margin: 0 0 10px;
  font-family: var(--font-brand);
  font-size: clamp(28px, 4vw, 40px);
  letter-spacing: 0.06em;
}

.cta-panel p {
  margin: 0 0 24px;
  max-width: 40ch;
  color: rgba(255, 255, 255, 0.85);
}

.cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* —— footer —— */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0 40px;
  color: var(--muted);
  font-size: 13px;
}

.footer-inner {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 24px;
  align-items: center;
  justify-content: space-between;
}

.footer-links {
  display: flex;
  gap: 16px;
}

.footer-links a:hover {
  color: var(--ink);
}

.section#flow {
  background: var(--paper);
}

@media (max-width: 960px) {
  .feature-list,
  .flow-track {
    grid-template-columns: 1fr 1fr;
  }

  .hero-stage {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .hero-ui {
    justify-content: flex-start;
  }

  .hero-ui .preview-shell {
    max-width: 100%;
  }

  .hero-desc {
    max-width: 42ch;
  }
}

@media (max-width: 720px) {
  .top-nav a:not(.btn) {
    display: none;
  }

  .feature-list,
  .flow-track {
    grid-template-columns: 1fr;
  }

  .hero {
    padding-top: 80px;
    min-height: 0;
  }

  .hero-stage {
    width: calc(100% - 24px);
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-copy,
  .hero-ui {
    animation: none;
  }
}