:root {
  color: #172033;
  background: #f5f7fb;
  font-family:
    Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI",
    "Microsoft YaHei", sans-serif;
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #111827;
  --muted: #667085;
  --line: #dfe7f2;
  --primary: #2563eb;
  --primary-strong: #1d4ed8;
  --header-height: 70px;
  --screen-height: calc(100svh - var(--header-height));
  --shadow: 0 24px 70px rgba(35, 48, 76, 0.14);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  scroll-snap-type: y mandatory;
}

body {
  margin: 0;
  min-width: 320px;
  color: var(--text);
  background: var(--bg);
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  min-height: var(--header-height);
  align-items: center;
  justify-content: space-between;
  padding: 0 clamp(20px, 6vw, 76px);
  border-bottom: 1px solid rgba(223, 231, 242, 0.9);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 18px;
  font-weight: 800;
}

.brand img {
  width: 34px;
  height: 34px;
  border-radius: 8px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: clamp(16px, 3vw, 32px);
  color: #42526b;
  font-size: 14px;
  font-weight: 700;
}

.nav-links a:hover {
  color: var(--primary-strong);
}

.nav-trial-button {
  display: inline-flex;
  min-height: 36px;
  align-items: center;
  justify-content: center;
  padding: 0 16px;
  border: 0;
  border-radius: 8px;
  background: #0f9f6e;
  color: #fff;
  font: inherit;
  font-size: 14px;
  font-weight: 800;
  cursor: pointer;
  transition: background 0.16s ease, transform 0.16s ease;
}

.nav-trial-button:hover {
  background: #0b7f59;
  transform: translateY(-1px);
}

.screen {
  display: grid;
  min-height: var(--screen-height);
  scroll-snap-align: start;
  align-items: center;
  gap: clamp(28px, 5vw, 72px);
  padding: clamp(32px, 5vh, 64px) clamp(20px, 7vw, 96px);
}

.screen:not(.hero-screen),
.about-screen {
  content-visibility: auto;
  contain-intrinsic-size: 900px;
}

.split-screen,
.hero-screen {
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
}

.hero-screen {
  height: var(--screen-height);
  min-height: var(--screen-height);
  overflow: hidden;
  scroll-margin-top: var(--header-height);
  scroll-snap-stop: always;
  background:
    linear-gradient(90deg, rgba(245, 247, 251, 0.98), rgba(245, 247, 251, 0.74)),
    linear-gradient(135deg, #f7fbff, #eaf2ff);
}

.marketing-screen {
  background:
    linear-gradient(135deg, rgba(247, 250, 255, 0.98), rgba(234, 242, 255, 0.86)),
    #f5f7fb;
}

.dark-screen {
  color: #f8fafc;
  background:
    radial-gradient(circle at 72% 34%, rgba(37, 99, 235, 0.24), transparent 36%),
    linear-gradient(135deg, #0f172a, #152238);
}

.about-screen {
  position: relative;
  display: grid;
  min-height: var(--screen-height);
  grid-template-columns: minmax(0, 0.95fr) minmax(360px, 1.05fr);
  gap: clamp(28px, 5vw, 72px);
  align-items: center;
  padding: clamp(32px, 5vh, 64px) clamp(20px, 7vw, 96px);
  scroll-snap-align: start;
  color: #f8fafc;
  background: #111b2e;
}

.about-copy {
  max-width: 700px;
}

.about-copy h2 {
  color: #fff;
}

.about-copy > p:not(.eyebrow) {
  max-width: 640px;
  margin: 22px 0 0;
  color: #cbd5e1;
  font-size: clamp(16px, 1.6vw, 20px);
  line-height: 1.75;
}

.contact-list {
  display: grid;
  max-width: 460px;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  margin: 40px 0 0;
  border-top: 1px solid rgba(255, 255, 255, 0.14);
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.contact-list > div {
  padding: 22px 24px 22px 0;
}

.contact-list > div + div {
  padding-left: 28px;
  border-left: 1px solid rgba(255, 255, 255, 0.14);
}

.contact-list dt {
  color: #8fa2bc;
  font-size: 12px;
  font-weight: 700;
}

.contact-list dd {
  margin: 7px 0 0;
  color: #fff;
  font-size: clamp(17px, 1.8vw, 22px);
  font-weight: 750;
}

.wechat-contact {
  justify-self: center;
  text-align: center;
}

.wechat-qr {
  display: block;
  width: 216px;
  height: auto;
  -webkit-touch-callout: default;
  user-select: auto;
  border-radius: 8px;
  box-shadow: 0 22px 60px rgba(0, 0, 0, 0.3);
}

.icp-bar {
  position: absolute;
  right: 0;
  bottom: 0;
  left: 0;
  display: flex;
  min-height: 48px;
  align-items: center;
  justify-content: center;
  gap: 24px;
  padding: 10px 20px;
  color: #94a3b8;
  background: #0a1220;
  font-size: 12px;
}

.icp-bar a:hover {
  color: #dbeafe;
}

.screen-copy {
  max-width: 680px;
  container-type: inline-size;
}

#hero-title {
  font-size: clamp(38px, 9.7cqw, 56px);
  white-space: nowrap;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--primary-strong);
  font-size: clamp(12px, 1.3vw, 14px);
  font-weight: 850;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.dark-screen .eyebrow {
  color: #93c5fd;
}

h1,
h2 {
  margin: 0;
  color: #0f172a;
  font-size: clamp(40px, 6.2vw, 76px);
  line-height: 1.06;
  font-weight: 860;
  letter-spacing: 0;
}

h2 {
  font-size: clamp(36px, 5.2vw, 64px);
}

.dark-screen h2 {
  color: #ffffff;
}

.screen-copy p:not(.eyebrow) {
  max-width: 620px;
  margin: clamp(16px, 2.4vh, 24px) 0 0;
  color: #43536c;
  font-size: clamp(16px, 1.65vw, 21px);
  line-height: 1.72;
}

.dark-screen .screen-copy p:not(.eyebrow) {
  color: #d7deeb;
}

.keyword-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(20px, 3vh, 34px);
}

.keyword-row span {
  display: inline-flex;
  min-height: 34px;
  align-items: center;
  padding: 0 13px;
  border: 1px solid rgba(37, 99, 235, 0.2);
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.76);
  color: #1f3b67;
  font-size: 13px;
  font-weight: 750;
}

.dark-screen .keyword-row span {
  border-color: rgba(147, 197, 253, 0.24);
  background: rgba(255, 255, 255, 0.08);
  color: #dbeafe;
}

.visual-frame,
.feature-board,
.marketing-board {
  overflow: hidden;
  margin: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--surface);
  box-shadow: var(--shadow);
}

.visual-frame {
  position: relative;
  justify-self: center;
}

.visual-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.visual-frame figcaption {
  position: absolute;
  right: 12px;
  bottom: 12px;
  padding: 7px 10px;
  border: 1px solid rgba(255, 255, 255, 0.32);
  border-radius: 6px;
  background: rgba(15, 23, 42, 0.78);
  color: #fff;
  font-size: 11px;
  font-weight: 700;
  backdrop-filter: blur(8px);
}

.visual-frame--sidebar {
  width: min(100%, clamp(260px, 37.5vh, 356px));
  aspect-ratio: 356 / 760;
}

.visual-frame--phone {
  width: min(100%, 690px);
  aspect-ratio: 1120 / 760;
  border-color: rgba(147, 197, 253, 0.2);
  background: #f5f7fb;
}

.visual-frame--phone img {
  object-position: center;
}

.feature-board {
  display: grid;
  gap: 0;
}

.feature-board article {
  display: grid;
  min-height: 150px;
  grid-template-columns: 62px 1fr;
  gap: 18px;
  align-items: start;
  padding: clamp(22px, 3vw, 34px);
  border-bottom: 1px solid #e7edf5;
}

.feature-board article:last-child {
  border-bottom: 0;
}

.feature-board article:hover {
  background: #f8fbff;
}

.feature-index {
  color: #9bb5e5;
  font-family: Consolas, "SFMono-Regular", monospace;
  font-size: 15px;
  font-weight: 800;
}

.feature-board strong {
  display: block;
  color: #172033;
  font-size: clamp(20px, 2vw, 26px);
  font-weight: 850;
}

.feature-board p,
.marketing-board p {
  margin: 9px 0 0;
  color: var(--muted);
  font-size: clamp(13px, 1.25vw, 15px);
  line-height: 1.65;
}

.marketing-board {
  display: grid;
  gap: 12px;
  padding: clamp(20px, 3vw, 34px);
  background: rgba(255, 255, 255, 0.9);
}

.marketing-board > div {
  position: relative;
  min-height: 132px;
  padding: clamp(20px, 2.4vw, 28px);
  overflow: hidden;
  border: 1px solid #d8e5fb;
  border-radius: 8px;
  background: #f8fbff;
}

.marketing-board > div::after {
  position: absolute;
  top: 0;
  right: 0;
  width: 8px;
  height: 100%;
  background: #2563eb;
  content: "";
  opacity: 0.9;
}

.marketing-board > div:nth-child(2)::after {
  background: #0f9f6e;
}

.marketing-board > div:nth-child(3)::after {
  background: #64748b;
}

.board-label {
  display: block;
  margin-bottom: 5px;
  color: #7892bd;
  font-size: 10px;
  font-weight: 850;
  letter-spacing: 0.08em;
}

.marketing-board strong {
  color: #111827;
  font-size: clamp(22px, 3vw, 32px);
  font-weight: 850;
}

.trial-overlay {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: flex;
  justify-content: flex-end;
  background: rgba(15, 23, 42, 0.42);
}

.trial-overlay[hidden] {
  display: none;
}

.trial-drawer {
  position: relative;
  width: min(100%, 440px);
  min-height: 100%;
  padding: 42px 32px;
  overflow-y: auto;
  background: #ffffff;
  box-shadow: -24px 0 70px rgba(15, 23, 42, 0.22);
}

.trial-close {
  position: absolute;
  top: 18px;
  right: 18px;
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border: 0;
  border-radius: 8px;
  background: #f1f5f9;
  color: #334155;
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.trial-close:hover {
  background: #e2e8f0;
}

.trial-drawer h2 {
  color: #111827;
  font-size: 34px;
}

.trial-copy {
  margin: 14px 0 26px;
  color: #667085;
  font-size: 15px;
  line-height: 1.7;
}

.trial-form {
  display: grid;
  gap: 16px;
}

.trial-form label {
  display: grid;
  gap: 8px;
  color: #344054;
  font-size: 14px;
  font-weight: 750;
}

.trial-form input {
  width: 100%;
  height: 44px;
  padding: 0 12px;
  border: 1px solid #d0d7e2;
  border-radius: 8px;
  background: #fff;
  color: #111827;
  font: inherit;
  outline: none;
}

.trial-form input:focus {
  border-color: #2563eb;
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

.trial-field-hint {
  color: #7a8699;
  font-size: 12px;
  font-weight: 500;
  line-height: 1.45;
}

.trial-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin-top: 4px;
}

.trial-primary,
.trial-secondary {
  min-height: 44px;
  border-radius: 8px;
  font: inherit;
  font-weight: 820;
  cursor: pointer;
}

.trial-primary {
  border: 0;
  background: #2563eb;
  color: #fff;
}

.trial-primary:hover {
  background: #1d4ed8;
}

.trial-secondary {
  border: 1px solid #cbd5e1;
  background: #fff;
  color: #1f2937;
}

.trial-secondary:hover {
  background: #f8fafc;
}

.trial-primary:disabled,
.trial-secondary:disabled {
  cursor: not-allowed;
  opacity: 0.62;
}

.trial-secondary[aria-busy="true"]::before {
  display: inline-block;
  width: 14px;
  height: 14px;
  margin-right: 7px;
  border: 2px solid rgba(37, 99, 235, 0.25);
  border-top-color: #2563eb;
  border-radius: 50%;
  vertical-align: -2px;
  animation: trial-spin 0.8s linear infinite;
  content: "";
}

.trial-message {
  min-height: 22px;
  margin: 0;
  color: #0f9f6e;
  font-size: 13px;
  line-height: 1.55;
}

.trial-message.error {
  color: #d92d20;
}

.trial-message.pending {
  color: #475467;
}

@keyframes trial-spin {
  to {
    transform: rotate(360deg);
  }
}

@media (max-height: 760px) and (min-width: 901px) {
  .screen {
    padding-top: 28px;
    padding-bottom: 28px;
  }

  h1 {
    font-size: clamp(38px, 5vw, 58px);
  }

  h2 {
    font-size: clamp(34px, 4.4vw, 52px);
  }

  .screen-copy p:not(.eyebrow) {
    font-size: 16px;
    line-height: 1.58;
  }

  .keyword-row {
    margin-top: 18px;
  }

  .visual-frame--sidebar {
    width: min(100%, 37.5vh);
  }

  .feature-board article {
    min-height: 126px;
    padding: 20px 24px;
  }

  .marketing-board {
    gap: 9px;
    padding: 20px;
  }

  .marketing-board > div {
    min-height: 105px;
    padding: 17px 20px;
  }
}

@media (max-width: 900px) {
  html {
    scroll-snap-type: none;
  }

  .nav-links {
    display: flex;
    gap: 0;
  }

  .nav-links a {
    display: none;
  }

  .split-screen,
  .hero-screen,
  .about-screen {
    grid-template-columns: 1fr;
  }

  .screen {
    min-height: auto;
  }

  .hero-screen {
    height: auto;
    min-height: auto;
    overflow: visible;
  }

  #hero-title {
    white-space: normal;
  }

  .visual-frame--sidebar {
    width: min(76vw, 356px);
  }

  .visual-frame--phone {
    width: min(100%, 690px);
  }

  .about-screen {
    min-height: auto;
    padding-bottom: 100px;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

@media (max-width: 720px) {
  :root {
    --header-height: 64px;
  }

  .site-header {
    padding: 0 20px;
  }

  .screen {
    gap: 26px;
    padding: 42px 20px;
  }

  h1,
  h2 {
    font-size: clamp(34px, 10vw, 44px);
  }

  .screen-copy p:not(.eyebrow) {
    font-size: 15px;
    line-height: 1.62;
  }

  .keyword-row {
    gap: 8px;
  }

  .keyword-row span {
    min-height: 30px;
    font-size: 12px;
  }

  .feature-board article {
    min-height: auto;
    grid-template-columns: 42px 1fr;
    gap: 10px;
    padding: 20px 16px;
  }

  .feature-board strong {
    font-size: 19px;
  }

  .marketing-board {
    padding: 14px;
  }

  .marketing-board > div {
    min-height: 112px;
    padding: 18px;
  }

  .visual-frame--phone {
    width: 100%;
  }

  .about-screen {
    gap: 42px;
    padding: 64px 20px 104px;
  }

  .contact-list {
    grid-template-columns: 1fr;
    margin-top: 30px;
  }

  .contact-list > div + div {
    padding-left: 0;
    border-top: 1px solid rgba(255, 255, 255, 0.14);
    border-left: 0;
  }

  .wechat-qr {
    width: 200px;
  }

  .icp-bar {
    flex-direction: column;
    gap: 4px;
    padding: 12px 20px;
  }

  .trial-drawer {
    width: 100%;
    padding: 38px 20px;
  }

  .trial-actions {
    grid-template-columns: 1fr;
  }
}