:root {
  color-scheme: light;
  --bg: #ffffff;
  --bg-2: #f7f8fa;
  --surface: rgba(255, 255, 255, 0.86);
  --surface-strong: #ffffff;
  --fg: #111318;
  --muted: #5f6878;
  --muted-2: #8a94a6;
  --line: rgba(0, 0, 0, 0.08);
  --line-strong: rgba(0, 0, 0, 0.16);
  --grid: rgba(0, 0, 0, 0.045);
  --brand: #1677ff;
  --brand-strong: #075bd8;
  --brand-soft: rgba(22, 119, 255, 0.11);
  --accent: #00d4aa;
  --accent-soft: rgba(0, 212, 170, 0.12);
  --danger: #d4392f;
  --warning: #f59f00;
  --shadow: 0 24px 80px rgba(14, 24, 45, 0.11);
  --shadow-soft: 0 16px 48px rgba(14, 24, 45, 0.08);
  --radius: 8px;
  --radius-sm: 6px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --header-h: 72px;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #05070a;
  --bg-2: #0b0e13;
  --surface: rgba(11, 14, 19, 0.8);
  --surface-strong: #0b0e13;
  --fg: #f5f7fa;
  --muted: #8a94a6;
  --muted-2: #5f6878;
  --line: rgba(255, 255, 255, 0.08);
  --line-strong: rgba(255, 255, 255, 0.18);
  --grid: rgba(255, 255, 255, 0.035);
  --brand: #4da3ff;
  --brand-strong: #1677ff;
  --brand-soft: rgba(22, 119, 255, 0.16);
  --accent: #00f0c8;
  --accent-soft: rgba(0, 240, 200, 0.12);
  --danger: #ff5a4d;
  --warning: #ffb84d;
  --shadow: 0 26px 90px rgba(0, 0, 0, 0.38);
  --shadow-soft: 0 18px 52px rgba(0, 0, 0, 0.3);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body {
  margin: 0;
  min-width: 320px;
  overflow-x: hidden;
  background:
    radial-gradient(circle at 18% 8%, var(--brand-soft), transparent 28rem),
    radial-gradient(circle at 82% 18%, var(--accent-soft), transparent 26rem),
    linear-gradient(180deg, var(--bg) 0%, var(--bg-2) 48%, var(--bg) 100%);
  color: var(--fg);
  font-family: "Manrope", "Noto Sans SC", "PingFang SC", "MiSans", sans-serif;
}

body.menu-open,
body.modal-open {
  overflow: hidden;
}

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

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

button {
  color: inherit;
  font: inherit;
}

code {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 0.92em;
}

::selection {
  background: var(--brand);
  color: #fff;
}

.skip-link {
  position: fixed;
  top: 12px;
  left: 12px;
  z-index: 200;
  transform: translateY(-160%);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  padding: 10px 14px;
  transition: transform 180ms var(--ease);
}

.skip-link:focus {
  transform: translateY(0);
}

.grid-bg {
  background-image:
    linear-gradient(var(--grid) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid) 1px, transparent 1px);
  background-size: 56px 56px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-h);
  padding: 0 clamp(18px, 5vw, 72px);
  border-bottom: 1px solid var(--line);
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: blur(24px) saturate(150%);
  transition: background 220ms var(--ease), box-shadow 220ms var(--ease), border-color 220ms var(--ease);
}

.site-header.is-scrolled {
  border-color: var(--line-strong);
  background: color-mix(in srgb, var(--bg) 93%, transparent);
  box-shadow: 0 12px 36px rgba(15, 23, 42, 0.08);
}

.brand,
.footer-signature {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-width: 0;
  font-weight: 760;
  letter-spacing: 0;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  box-shadow: 0 12px 30px color-mix(in srgb, var(--brand) 22%, transparent);
}

.brand-text {
  font-family: "Space Grotesk", "Noto Sans SC", sans-serif;
  font-size: 18px;
}

.desktop-nav {
  display: flex;
  align-items: center;
  gap: 4px;
  margin-left: auto;
  margin-right: 20px;
}

.desktop-nav a,
.footer-links a {
  display: inline-flex;
  align-items: center;
  min-height: 36px;
  border-radius: var(--radius-sm);
  padding: 0 12px;
  color: var(--muted);
  font-size: 14px;
  font-weight: 650;
  transition: color 160ms var(--ease), background 160ms var(--ease);
}

.desktop-nav a:hover,
.footer-links a:hover {
  color: var(--fg);
  background: color-mix(in srgb, var(--fg) 5%, transparent);
}

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

.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border-radius: var(--radius-sm);
  background: var(--fg);
  color: var(--bg);
  padding: 0 17px;
  font-size: 14px;
  font-weight: 760;
  box-shadow: 0 12px 28px rgba(17, 19, 24, 0.16);
  transition: transform 180ms var(--ease), box-shadow 180ms var(--ease);
}

.header-login {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 40px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--surface-strong) 84%, transparent);
  color: var(--fg);
  padding: 0 15px;
  font-size: 14px;
  font-weight: 760;
  transition: transform 180ms var(--ease), border-color 180ms var(--ease), box-shadow 180ms var(--ease);
}

.header-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 18px 40px rgba(17, 19, 24, 0.22);
}

.header-login:hover {
  transform: translateY(-1px);
  border-color: var(--brand);
  box-shadow: var(--shadow-soft);
}

.icon-button {
  display: inline-grid;
  place-items: center;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
  cursor: pointer;
  transition: border-color 160ms var(--ease), background 160ms var(--ease), transform 160ms var(--ease);
}

.icon-button:hover {
  transform: translateY(-1px);
  border-color: var(--line-strong);
}

.theme-glyph {
  width: 17px;
  height: 17px;
  border: 2px solid var(--fg);
  border-radius: 50%;
  box-shadow: inset -5px -5px 0 0 color-mix(in srgb, var(--fg) 24%, transparent);
}

.mobile-menu-button {
  display: none;
  width: 40px;
  height: 40px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface);
  padding: 0;
}

.mobile-menu-button span {
  display: block;
  width: 18px;
  height: 2px;
  margin: 4px auto;
  border-radius: 999px;
  background: var(--fg);
  transition: transform 180ms var(--ease), opacity 180ms var(--ease);
}

.menu-open .mobile-menu-button span:first-child {
  transform: translateY(3px) rotate(45deg);
}

.menu-open .mobile-menu-button span:last-child {
  transform: translateY(-3px) rotate(-45deg);
}

.mobile-nav {
  display: none;
}

.hero-section,
.section,
.site-footer {
  width: min(1400px, calc(100% - 40px));
  margin: 0 auto;
}

.hero-section {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 0.86fr) minmax(560px, 1.14fr);
  align-items: center;
  gap: clamp(36px, 6vw, 86px);
  min-height: calc(100vh - var(--header-h));
  padding: clamp(64px, 8vw, 112px) 0 72px;
}

.hero-copy {
  position: relative;
  z-index: 2;
}

.eyebrow-row {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 26px;
}

.eyebrow,
.section-index,
.recommend-label,
.status-pill,
.matrix-title {
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.eyebrow,
.section-index,
.recommend-label {
  color: var(--brand);
}

.eyebrow-line {
  width: 44px;
  height: 1px;
  background: var(--line-strong);
}

.eyebrow-note {
  color: var(--muted);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 10px;
  font-weight: 650;
  letter-spacing: 0.18em;
  text-transform: uppercase;
}

.hero-copy h1,
.section-heading h2,
.lite-copy h2,
.ai-copy h2,
.cloud-copy h2 {
  margin: 0;
  font-family: "Space Grotesk", "Noto Sans SC", sans-serif;
  letter-spacing: 0;
  text-wrap: balance;
}

.hero-copy h1 {
  max-width: 780px;
  font-size: clamp(4.6rem, 9.2vw, 8.6rem);
  line-height: 0.88;
  font-weight: 700;
}

.hero-subtitle {
  max-width: 660px;
  margin: 22px 0 0;
  color: var(--fg);
  font-family: "Space Grotesk", "Noto Sans SC", sans-serif;
  font-size: clamp(1.6rem, 3vw, 2.65rem);
  font-weight: 700;
  line-height: 1.08;
  text-wrap: balance;
}

.hero-lede {
  max-width: 640px;
  margin: 18px 0 0;
  color: var(--muted);
  font-size: clamp(17px, 1.6vw, 20px);
  line-height: 1.85;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-top: 38px;
}

.button,
.inline-download {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 50px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  padding: 0 22px;
  cursor: pointer;
  font-weight: 760;
  transition:
    transform 180ms var(--ease),
    box-shadow 180ms var(--ease),
    border-color 180ms var(--ease),
    background 180ms var(--ease),
    color 180ms var(--ease);
}

.button.primary,
.inline-download {
  background: var(--brand);
  color: #fff;
  box-shadow: 0 16px 38px color-mix(in srgb, var(--brand) 28%, transparent);
}

.button.primary:hover,
.inline-download:hover {
  transform: translateY(-2px);
  box-shadow: 0 22px 52px color-mix(in srgb, var(--brand) 34%, transparent);
}

.button.is-disabled,
.button[disabled] {
  border-color: var(--line);
  background: color-mix(in srgb, var(--muted) 12%, transparent);
  color: var(--muted);
  cursor: not-allowed;
  box-shadow: none;
}

.button.is-disabled:hover,
.button[disabled]:hover {
  transform: none;
  box-shadow: none;
}

.button.secondary {
  border-color: var(--line-strong);
  background: color-mix(in srgb, var(--surface-strong) 76%, transparent);
  color: var(--fg);
}

.button.secondary:hover {
  transform: translateY(-2px);
  border-color: var(--brand);
  box-shadow: var(--shadow-soft);
}

.button-mark {
  margin-left: 12px;
  font-family: "JetBrains Mono", ui-monospace, monospace;
}

.planned-downloads p strong,
.footer-meta a,
.agreement-check a {
  color: var(--brand);
  font-weight: 760;
}

.hero-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 34px;
}

.hero-badges span,
.provider-chip {
  display: inline-flex;
  align-items: center;
  min-height: 32px;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  padding: 0 12px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
}

.provider-chip {
  --provider-color: var(--brand);
  --provider-soft: color-mix(in srgb, var(--provider-color) 10%, var(--surface-strong));
  gap: 9px;
  min-height: 38px;
  border-color: color-mix(in srgb, var(--provider-color) 26%, var(--line));
  background:
    linear-gradient(135deg, color-mix(in srgb, var(--provider-color) 12%, transparent), transparent 58%),
    var(--provider-soft);
  color: color-mix(in srgb, var(--provider-color) 72%, var(--fg));
  font-weight: 760;
  transition:
    transform 180ms var(--ease),
    border-color 180ms var(--ease),
    box-shadow 180ms var(--ease),
    background 180ms var(--ease);
}

.provider-chip img,
.provider-chip i {
  width: 20px;
  height: 20px;
  flex: 0 0 20px;
}

.provider-chip img {
  color: currentColor;
}

.provider-chip i {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 5px;
  background: color-mix(in srgb, var(--provider-color) 14%, transparent);
  color: currentColor;
  font-style: normal;
  font-size: 12px;
  font-weight: 900;
}

.provider-ark i::before {
  content: "火";
}

.provider-chip:hover {
  transform: translateY(-2px);
  border-color: color-mix(in srgb, var(--provider-color) 52%, var(--line));
  box-shadow: 0 10px 30px color-mix(in srgb, var(--provider-color) 12%, transparent);
}

.provider-chip:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--provider-color) 28%, transparent);
  outline-offset: 2px;
}

.provider-kimi {
  --provider-color: #2f66ff;
}

.provider-ark {
  --provider-color: #6c5cff;
}

.provider-alibaba {
  --provider-color: #ff6a00;
}

.provider-glm {
  --provider-color: #22c55e;
}

.provider-claude {
  --provider-color: #d97757;
}

.provider-openai {
  --provider-color: #10a37f;
}

.provider-github {
  --provider-color: #6f42c1;
}

.provider-more {
  --provider-color: #1677ff;
  cursor: default;
}

:root[data-theme="dark"] .provider-chip {
  --provider-soft: color-mix(in srgb, var(--provider-color) 18%, var(--surface-strong));
  border-color: color-mix(in srgb, var(--provider-color) 34%, var(--line));
  color: color-mix(in srgb, var(--provider-color) 58%, #ffffff);
}

.hero-visual {
  position: relative;
  min-width: 0;
  padding: 22px 0 76px;
}

.screen-frame {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow);
  backdrop-filter: blur(18px) saturate(150%);
}

.screen-toolbar {
  display: flex;
  align-items: center;
  gap: 12px;
  min-height: 42px;
  border-bottom: 1px solid var(--line);
  padding: 0 14px;
  color: var(--muted);
  font-size: 12px;
}

.screen-toolbar strong {
  color: var(--fg);
  font-size: 13px;
}

.screen-toolbar span:last-child {
  margin-left: auto;
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.window-dots {
  display: inline-flex;
  gap: 6px;
}

.window-dots i {
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--line-strong);
}

.hero-screen {
  transform: rotateY(-4deg) rotateX(1deg);
  transform-origin: center;
  transition: transform 260ms var(--ease);
}

.hero-screen img,
.interface-shot img,
.lite-screen img,
.ai-main-screen img {
  width: 100%;
  aspect-ratio: 2054 / 1254;
  object-fit: cover;
  object-position: top left;
  background: var(--bg-2);
}

.hero-screen img {
  min-height: 400px;
}

.recommend-panel {
  position: absolute;
  right: 18px;
  bottom: 12px;
  width: min(360px, calc(100% - 36px));
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-strong) 88%, transparent);
  padding: 18px;
  box-shadow: var(--shadow-soft);
  backdrop-filter: blur(18px) saturate(150%);
}

.recommend-panel strong {
  display: block;
  margin-top: 8px;
  font-size: 24px;
  line-height: 1.16;
}

.recommend-panel p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.7;
  text-wrap: pretty;
}

.section {
  padding: clamp(76px, 9vw, 130px) 0;
}

.section-heading {
  max-width: 820px;
  margin-bottom: 42px;
}

.section-heading h2,
.lite-copy h2,
.ai-copy h2,
.cloud-copy h2 {
  margin-top: 14px;
  font-size: clamp(2rem, 4.7vw, 4.2rem);
  line-height: 1.04;
  font-weight: 700;
}

.section-heading p,
.lite-copy p,
.ai-copy p,
.cloud-copy p {
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.85;
  text-wrap: pretty;
}

.platform-grid,
.download-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.platform-card,
.download-card,
.feature-item {
  min-height: 100%;
  background: color-mix(in srgb, var(--surface-strong) 93%, transparent);
  padding: clamp(24px, 3vw, 34px);
}

.download-card {
  display: flex;
  flex-direction: column;
}

.platform-card h3,
.download-card h3,
.feature-item h3 {
  margin: 18px 0 0;
  font-size: clamp(1.25rem, 2vw, 1.8rem);
  line-height: 1.16;
  text-wrap: balance;
}

.platform-card p,
.download-card p,
.feature-item p {
  margin: 16px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.8;
  text-wrap: pretty;
}

.release-meta {
  display: block;
  color: var(--muted-2);
  font-size: 12px;
  font-weight: 720;
  line-height: 1.6;
}

.release-meta {
  margin-top: 10px;
}

.download-card p {
  flex: 1 1 auto;
  min-height: 52px;
}

.download-card .button {
  align-self: flex-start;
  margin-top: 22px;
}

.download-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 22px;
}

.download-card .download-actions .button {
  margin-top: 0;
}

.button.compact {
  min-height: 46px;
  padding: 0 16px;
  font-size: 14px;
}

.status-pill {
  display: inline-flex;
  align-items: center;
  min-height: 28px;
  border-radius: var(--radius-sm);
  padding: 0 10px;
}

.status-pill.available {
  background: var(--brand-soft);
  color: var(--brand);
}

.status-pill.planned {
  background: color-mix(in srgb, var(--muted) 12%, transparent);
  color: var(--muted);
}

.inline-download {
  margin-top: 24px;
  min-height: 42px;
  padding: 0 15px;
  font-size: 14px;
}

.support-matrix {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 26px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.support-column {
  background: color-mix(in srgb, var(--surface-strong) 92%, transparent);
  padding: 24px;
}

.matrix-title {
  color: var(--muted);
}

.support-column ul {
  display: grid;
  gap: 9px;
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
}

.support-column li,
.support-column p {
  color: var(--fg);
  font-size: 14px;
  line-height: 1.8;
}

.support-column p {
  margin: 16px 0 0;
  color: var(--muted);
  text-wrap: pretty;
}

.interface-showcase {
  display: grid;
  gap: clamp(42px, 7vw, 86px);
}

.interface-story {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(310px, 0.75fr);
  align-items: center;
  gap: clamp(28px, 5vw, 64px);
  border-top: 1px solid var(--line);
  padding-top: clamp(28px, 4vw, 44px);
}

.interface-story:first-child {
  border-top: 0;
  padding-top: 0;
}

.interface-story-reverse .interface-shot {
  order: 2;
}

.interface-shot {
  box-shadow: var(--shadow-soft);
}

.interface-copy {
  align-self: center;
}

.story-index {
  color: var(--brand);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 11px;
  font-weight: 760;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

.interface-copy h3 {
  margin: 14px 0 0;
  font-size: clamp(1.8rem, 3.4vw, 3.2rem);
  line-height: 1.04;
  text-wrap: balance;
}

.interface-copy p {
  margin: 18px 0 0;
  color: var(--muted);
  font-size: 15px;
  line-height: 1.85;
  text-wrap: pretty;
}

.interface-points {
  display: grid;
  gap: 10px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.interface-points li {
  position: relative;
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: color-mix(in srgb, var(--surface-strong) 86%, transparent);
  padding: 10px 12px 10px 28px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 650;
  line-height: 1.55;
}

.interface-points li::before {
  content: "";
  position: absolute;
  left: 12px;
  top: 18px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--brand);
}

.lite-section,
.ai-section,
.cloud-section {
  display: grid;
  grid-template-columns: minmax(0, 0.82fr) minmax(520px, 1.18fr);
  align-items: center;
  gap: clamp(34px, 6vw, 78px);
}

.lite-compare {
  display: grid;
  gap: 12px;
  margin-top: 30px;
}

.lite-compare div {
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  padding: 18px;
}

.lite-compare strong {
  display: block;
  margin-bottom: 8px;
  font-size: 18px;
}

.lite-compare span {
  color: var(--muted);
  font-size: 14px;
  line-height: 1.75;
}

.lite-screen {
  transform: rotateY(3deg);
}

.feature-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 28px;
  border-radius: var(--radius-sm);
  background: var(--brand-soft);
  color: var(--brand);
  font-family: "JetBrains Mono", ui-monospace, monospace;
  font-size: 12px;
  font-weight: 800;
}

.ai-provider-panel {
  margin-top: 28px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  padding: 16px;
}

.provider-kicker {
  display: block;
  margin-bottom: 12px;
  color: var(--muted-2);
  font-size: 12px;
  font-weight: 800;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

.ai-provider-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.ai-note {
  margin: 16px 0 0;
  border: 1px solid color-mix(in srgb, var(--warning) 32%, var(--line));
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--warning) 8%, var(--surface-strong));
  padding: 13px 15px;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.75;
  text-wrap: pretty;
}

.ai-screens {
  display: grid;
  gap: 14px;
}

.ai-main-screen {
  box-shadow: var(--shadow-soft);
}

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

.ai-mini-grid img {
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  object-position: top left;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface);
  box-shadow: var(--shadow-soft);
}

.cloud-section {
  align-items: start;
}

.cloud-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 34px;
}

.cloud-preview {
  display: grid;
  justify-items: center;
}

.cloud-purpose-panel {
  width: min(560px, 100%);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-strong) 94%, transparent);
  box-shadow: var(--shadow-soft);
}

.cloud-purpose-panel {
  padding: clamp(18px, 2.4vw, 26px);
}

.cloud-purpose-head {
  display: flex;
  align-items: center;
  gap: 12px;
}

.cloud-purpose-head img {
  width: 40px;
  height: 40px;
  border-radius: 9px;
  box-shadow: 0 12px 28px color-mix(in srgb, var(--brand) 20%, transparent);
}

.cloud-purpose-head strong,
.cloud-purpose-head span {
  display: block;
}

.cloud-purpose-head strong {
  color: var(--fg);
  font-size: 18px;
  line-height: 1.2;
}

.cloud-purpose-head span {
  margin-top: 3px;
  color: var(--muted);
  font-size: 12px;
  font-weight: 700;
}

.cloud-purpose-list {
  display: grid;
  gap: 1px;
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
  background: var(--line);
}

.cloud-purpose-list div {
  display: grid;
  gap: 8px;
  background: color-mix(in srgb, var(--surface-strong) 92%, transparent);
  padding: 18px;
}

.cloud-purpose-list strong {
  color: var(--fg);
  font-size: 17px;
  line-height: 1.28;
}

.cloud-purpose-list span {
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
  text-wrap: pretty;
}

.download-card {
  position: relative;
}

.download-card.is-recommended {
  background:
    linear-gradient(0deg, var(--brand-soft), var(--brand-soft)),
    color-mix(in srgb, var(--surface-strong) 93%, transparent);
}

.download-card.is-recommended::after {
  content: "推荐";
  position: absolute;
  top: 24px;
  right: 24px;
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  border-radius: var(--radius-sm);
  background: var(--fg);
  color: var(--bg);
  padding: 0 9px;
  font-size: 12px;
  font-weight: 800;
}

.disabled-button {
  margin-top: 24px;
  border-color: var(--line);
  background: color-mix(in srgb, var(--muted) 10%, transparent);
  color: var(--muted);
  cursor: not-allowed;
}

.planned-downloads {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 18px;
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: color-mix(in srgb, var(--surface-strong) 84%, transparent);
  padding: 16px 18px;
  color: var(--muted);
}

.planned-downloads ul {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 12px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.planned-downloads li {
  font-size: 13px;
  font-weight: 650;
  color: var(--fg);
}

.planned-downloads p {
  flex-basis: 100%;
  margin: 0;
  color: var(--muted);
  font-size: 13px;
  line-height: 1.7;
  text-wrap: pretty;
}

.site-footer {
  position: relative;
  display: grid;
  gap: 10px;
  border-top: 1px solid var(--line);
  padding: 26px 0 32px;
}

.footer-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 22px;
}

.footer-signature {
  gap: 9px;
  flex: 1 1 auto;
}

.footer-studio-mark {
  position: relative;
  width: 24px;
  height: 24px;
  flex: none;
  background: url("../brand/bhcn-logo-symbol-light.svg") center / contain no-repeat;
  opacity: 0.9;
}

:root[data-theme="dark"] .footer-studio-mark {
  background-image: url("../brand/bhcn-logo-symbol-dark.svg");
}

.footer-signature strong {
  display: block;
  color: var(--fg);
  font-family: "Space Grotesk", "Noto Sans SC", sans-serif;
  font-size: 13px;
  letter-spacing: 0;
  line-height: 1.2;
}

.footer-signature span {
  display: block;
  margin-top: 2px;
  color: var(--muted);
  font-size: 11px;
  font-weight: 620;
  line-height: 1.5;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  justify-content: flex-end;
  gap: 4px;
}

.footer-links a {
  min-height: 28px;
  padding: 0 8px;
  font-size: 12px;
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px 14px;
  color: var(--muted);
  font-family: "JetBrains Mono", "Noto Sans SC", ui-monospace, monospace;
  font-size: 11px;
}

.download-modal {
  position: fixed;
  inset: 0;
  z-index: 180;
  display: grid;
  place-items: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 180ms var(--ease);
}

.download-modal.is-open {
  opacity: 1;
  pointer-events: auto;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.52);
  backdrop-filter: blur(14px);
}

.modal-panel {
  position: relative;
  width: min(560px, 100%);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--surface-strong);
  box-shadow: 0 30px 110px rgba(0, 0, 0, 0.32);
  padding: clamp(24px, 4vw, 34px);
}

.modal-close {
  position: absolute;
  top: 14px;
  right: 14px;
  font-size: 24px;
  line-height: 1;
}

.modal-panel h2 {
  margin: 14px 0 0;
  font-size: clamp(2rem, 5vw, 3rem);
  line-height: 1.05;
}

.modal-panel p {
  margin: 14px 0 0;
  color: var(--muted);
  line-height: 1.8;
}

.modal-version {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: 22px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--bg-2);
  padding: 14px 16px;
}

.modal-version span {
  color: var(--muted);
  font-size: 13px;
}

.modal-version strong {
  text-align: right;
}

.agreement-check {
  display: flex;
  gap: 12px;
  margin-top: 22px;
  color: var(--muted);
  line-height: 1.7;
}

.agreement-check input {
  width: 19px;
  height: 19px;
  margin-top: 3px;
  accent-color: var(--brand);
  flex: none;
}

.modal-actions {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
  margin-top: 26px;
}

.modal-actions .button[disabled] {
  opacity: 0.46;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.download-fallback-toast {
  position: fixed;
  top: calc(var(--header-h) + 14px);
  right: 16px;
  z-index: 190;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto auto;
  align-items: center;
  gap: 12px;
  width: min(460px, calc(100vw - 32px));
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  background: var(--surface-strong);
  box-shadow: 0 20px 70px rgba(0, 0, 0, 0.18);
  padding: 12px;
  transform: translateX(calc(100% + 28px));
  opacity: 0;
  transition: transform 260ms var(--ease), opacity 260ms var(--ease);
}

.download-fallback-toast.is-visible {
  transform: translateX(0);
  opacity: 1;
}

.download-fallback-toast strong,
.download-fallback-toast span {
  display: block;
}

.download-fallback-toast strong {
  color: var(--fg);
  font-size: 14px;
  line-height: 1.35;
}

.download-fallback-toast span {
  margin-top: 2px;
  color: var(--muted);
  font-size: 12px;
  line-height: 1.45;
}

.toast-close {
  width: 30px;
  height: 30px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--bg-2);
  color: var(--muted);
  cursor: pointer;
  font-size: 18px;
  line-height: 1;
}

.reveal {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 560ms var(--ease), transform 560ms var(--ease);
}

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

.delay-1 {
  transition-delay: 90ms;
}

.delay-2 {
  transition-delay: 160ms;
}

@media (hover: hover) {
  .hero-visual:hover .hero-screen {
    transform: rotateY(-2deg) rotateX(0deg) translateY(-4px);
  }
}

@media (max-width: 1180px) {
  .hero-section,
  .lite-section,
  .ai-section,
  .cloud-section {
    grid-template-columns: 1fr;
  }

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

  .hero-visual {
    padding-bottom: 64px;
  }

  .interface-story {
    grid-template-columns: 1fr;
  }

  .interface-story-reverse .interface-shot {
    order: initial;
  }

  .interface-copy {
    max-width: 760px;
  }
}

@media (max-width: 900px) {
  .desktop-nav,
  .header-cta,
  .header-login {
    display: none;
  }

  .mobile-menu-button {
    display: block;
  }

  .mobile-nav {
    position: fixed;
    top: var(--header-h);
    left: 0;
    right: 0;
    display: grid;
    gap: 1px;
    border-bottom: 1px solid var(--line);
    background: var(--line);
    transform: translateY(-120%);
    transition: transform 220ms var(--ease);
  }

  .menu-open .mobile-nav {
    transform: translateY(0);
  }

  .mobile-nav a {
    min-height: 52px;
    background: var(--surface-strong);
    padding: 0 22px;
    display: flex;
    align-items: center;
    font-weight: 760;
  }

  .site-footer {
    grid-template-columns: 1fr;
    flex-direction: column;
    align-items: stretch;
  }

  .footer-row {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .footer-links {
    justify-content: flex-start;
  }

  .platform-grid,
  .download-grid,
  .feature-grid,
  .support-matrix {
    grid-template-columns: 1fr;
  }

}

@media (max-width: 620px) {
  .hero-section,
  .section,
  .site-footer {
    width: min(100% - 28px, 1400px);
  }

  .brand-text {
    font-size: 16px;
  }

  .hero-section {
    padding-top: 52px;
  }

  .hero-copy h1 {
    font-size: clamp(3.2rem, 17vw, 5rem);
  }

  .hero-subtitle {
    font-size: clamp(1.45rem, 8vw, 2.25rem);
  }

  .hero-actions,
  .modal-actions {
    flex-direction: column;
  }

  .button,
  .inline-download {
    width: 100%;
  }

  .hero-badges span,
  .provider-chip {
    width: 100%;
  }

  .hero-screen img {
    min-height: 260px;
  }

  .recommend-panel {
    position: relative;
    right: auto;
    bottom: auto;
    width: 100%;
    margin-top: 12px;
  }

  .hero-visual {
    padding: 0;
  }

  .screen-toolbar {
    min-height: 38px;
    gap: 8px;
  }

  .screen-toolbar span:last-child {
    display: none;
  }

  .ai-mini-grid {
    grid-template-columns: 1fr;
  }


  .footer-studio-mark {
    width: 23px;
    height: 23px;
  }

  .footer-links {
    gap: 2px 4px;
  }

  .footer-meta {
    font-size: 11px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }

  .reveal {
    opacity: 1;
    transform: none;
  }
}