:root {
  --brand: #1677ff;
  --brand-deep: #0b5ed7;
  --ink: #132033;
  --ink-soft: #4a5a70;
  --line: rgba(19, 32, 51, 0.1);
  --paper: #f3f6fb;
  --white: #ffffff;
  --font-display: "Syne", "IBM Plex Sans SC", sans-serif;
  --font-body: "IBM Plex Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --radius: 14px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--ink);
  background: var(--paper);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

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

.noise {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 50;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* —— Top bar —— */
.topbar {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  padding: 22px clamp(20px, 4vw, 48px);
}

.logo {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 15px;
  letter-spacing: 0.02em;
}

.logo-mark {
  width: 22px;
  height: 22px;
  border-radius: 7px;
  background:
    linear-gradient(135deg, #3d8fff 0%, var(--brand) 55%, #0a4fc4 100%);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.25);
}

.logo-text {
  color: var(--ink);
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100svh;
  display: flex;
  align-items: center;
  overflow: hidden;
  isolation: isolate;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(ellipse 80% 60% at 15% 20%, rgba(22, 119, 255, 0.22), transparent 55%),
    radial-gradient(ellipse 70% 50% at 90% 10%, rgba(90, 170, 255, 0.18), transparent 50%),
    radial-gradient(ellipse 60% 45% at 70% 90%, rgba(22, 119, 255, 0.1), transparent 55%),
    linear-gradient(165deg, #eaf2ff 0%, #f3f6fb 42%, #e8eef8 100%);
}

.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(22, 119, 255, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(22, 119, 255, 0.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 40%, #000 20%, transparent 75%);
}

.hero-inner {
  width: min(1120px, 100%);
  margin: 0 auto;
  padding: 110px clamp(20px, 4vw, 48px) 72px;
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(40px, 6vw, 72px);
  align-items: center;
}

.brand {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: clamp(2.8rem, 7vw, 4.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  line-height: 1.05;
  color: var(--ink);
}

.headline {
  margin: 0 0 14px;
  font-size: clamp(1.2rem, 2.4vw, 1.55rem);
  font-weight: 600;
  line-height: 1.35;
  color: var(--ink);
}

.lede {
  margin: 0 0 28px;
  max-width: 34em;
  font-size: 1.02rem;
  color: var(--ink-soft);
}

.cta {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 12px;
}

.btn-primary {
  appearance: none;
  border: none;
  cursor: pointer;
  font: inherit;
  font-weight: 600;
  font-size: 1rem;
  color: var(--white);
  background: var(--brand);
  padding: 14px 22px;
  border-radius: var(--radius);
  transition: background 0.25s var(--ease), transform 0.25s var(--ease);
}

.btn-primary:hover {
  background: var(--brand-deep);
  transform: translateY(-1px);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-primary.is-copied {
  background: #0f9d6e;
}

.cta-hint {
  margin: 0;
  font-size: 0.92rem;
  color: var(--ink-soft);
}

/* —— Phone mock —— */
.hero-visual {
  display: flex;
  justify-content: center;
}

.phone {
  position: relative;
  width: min(300px, 78vw);
  animation: float-y 5.5s var(--ease) infinite;
}

@keyframes float-y {
  0%, 100% { transform: translateY(0); }
  50% { transform: translateY(-10px); }
}

.phone-bezel {
  background: #1a2433;
  border-radius: 36px;
  padding: 10px;
  box-shadow:
    0 28px 60px rgba(19, 32, 51, 0.18),
    0 0 0 1px rgba(255, 255, 255, 0.08) inset;
}

.phone-notch {
  position: absolute;
  top: 18px;
  left: 50%;
  transform: translateX(-50%);
  width: 88px;
  height: 18px;
  background: #1a2433;
  border-radius: 0 0 12px 12px;
  z-index: 2;
}

.phone-screen {
  background: #f5f6fa;
  border-radius: 28px;
  min-height: 520px;
  padding: 42px 16px 16px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.mock-nav {
  text-align: center;
  font-weight: 600;
  font-size: 15px;
  color: var(--ink);
  padding-bottom: 6px;
}

.mock-panel {
  background: var(--white);
  border-radius: 12px;
  padding: 18px 16px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.04);
}

.mock-label {
  font-size: 13px;
  font-weight: 500;
  margin-bottom: 10px;
  color: var(--ink);
}

.mock-input {
  background: #f0f3f8;
  border-radius: 10px;
  padding: 14px 12px;
  font-size: 12px;
  color: #7a8799;
  min-height: 72px;
  margin-bottom: 14px;
  word-break: break-all;
}

.mock-btn {
  background: var(--brand);
  color: #fff;
  text-align: center;
  border-radius: 10px;
  padding: 12px;
  font-size: 14px;
  font-weight: 600;
}

.mock-tabs {
  margin-top: auto;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 4px;
  background: var(--white);
  border-radius: 12px;
  padding: 12px 8px;
  font-size: 12px;
  text-align: center;
  color: #8a97a8;
}

.mock-tabs .on {
  color: var(--brand);
  font-weight: 600;
}

/* —— Sections —— */
.section {
  padding: clamp(72px, 10vw, 110px) clamp(20px, 4vw, 48px);
}

.section-inner {
  width: min(960px, 100%);
  margin: 0 auto;
}

.section-title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.15;
}

.section-lede {
  margin: 0 0 40px;
  color: var(--ink-soft);
  font-size: 1.05rem;
  max-width: 28em;
}

.steps {
  background:
    linear-gradient(180deg, #eef3fa 0%, var(--paper) 100%);
  border-top: 1px solid var(--line);
}

.step-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.step {
  display: grid;
  grid-template-columns: 72px 1fr;
  gap: 18px;
  align-items: start;
  padding: 28px 0;
  border-top: 1px solid var(--line);
}

.step:last-child {
  border-bottom: 1px solid var(--line);
}

.step-num {
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--brand);
  letter-spacing: 0.02em;
  line-height: 1.2;
  padding-top: 2px;
}

.step h3 {
  margin: 0 0 6px;
  font-size: 1.15rem;
  font-weight: 600;
}

.step p {
  margin: 0;
  color: var(--ink-soft);
}

.features {
  background: var(--white);
  border-top: 1px solid var(--line);
}

.feature-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 36px;
}

.feature h3 {
  margin: 0 0 8px;
  font-size: 1.2rem;
  font-weight: 600;
}

.feature h3::before {
  content: "";
  display: inline-block;
  width: 10px;
  height: 10px;
  margin-right: 10px;
  border-radius: 2px;
  background: var(--brand);
  vertical-align: middle;
  transform: translateY(-1px);
}

.feature p {
  margin: 0;
  color: var(--ink-soft);
  max-width: 36em;
  padding-left: 20px;
}

/* —— Footer —— */
.footer {
  border-top: 1px solid var(--line);
  background: #e8eef6;
  padding: 48px clamp(20px, 4vw, 48px) 56px;
}

.footer-inner {
  width: min(960px, 100%);
  margin: 0 auto;
}

.footer-brand {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.1rem;
}

.footer-note {
  margin: 0 0 20px;
  max-width: 40em;
  font-size: 0.9rem;
  color: var(--ink-soft);
}

.footer-meta {
  margin: 0;
  font-size: 0.85rem;
  color: #7a8799;
}

.footer-sep {
  margin: 0 0.45em;
}

.footer-beian {
  color: inherit;
  text-decoration: none;
}

.footer-beian:hover {
  color: var(--accent);
  text-decoration: underline;
}

.footer-gongan {
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.footer-gongan-icon {
  display: block;
  flex-shrink: 0;
}

/* —— Reveal motion —— */
.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.delay-1 { transition-delay: 0.08s; }
.reveal.delay-2 { transition-delay: 0.16s; }
.reveal.delay-3 { transition-delay: 0.24s; }

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

@media (prefers-reduced-motion: reduce) {
  .reveal {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .phone {
    animation: none;
  }

  .btn-primary {
    transition: none;
  }
}

/* —— Responsive —— */
@media (max-width: 860px) {
  .hero-inner {
    grid-template-columns: 1fr;
    padding-top: 100px;
    padding-bottom: 56px;
    gap: 48px;
  }

  .hero-visual {
    order: -1;
  }

  .phone {
    width: min(260px, 70vw);
  }

  .phone-screen {
    min-height: 440px;
  }

  .brand {
    text-align: center;
  }

  .headline,
  .lede,
  .cta {
    text-align: center;
  }

  .cta {
    align-items: center;
  }

  .lede {
    margin-left: auto;
    margin-right: auto;
  }

  .topbar {
    justify-content: center;
  }
}

@media (max-width: 480px) {
  .step {
    grid-template-columns: 56px 1fr;
    gap: 12px;
  }
}