:root {
  color-scheme: light;
  --brand: #2563eb;
  --brand-strong: #1d4ed8;
  --brand-soft: #eff6ff;
  --brand-rgb: 37, 99, 235;
  --on-brand: #ffffff;
  --bg: #ffffff;
  --wash: #f7f8fa;
  --panel: #ffffff;
  --panel-2: #fafafa;
  --border: #e8e9ec;
  --border-strong: #d5d7dc;
  --text: #373a40;
  --heading: #111318;
  --muted: #70747d;
  --accent: var(--brand);
  --accent-2: var(--brand-strong);
  --tint: var(--brand-soft);
  --focus-ring: rgba(var(--brand-rgb), .16);
  --radius: 8px;
  --radius-lg: 16px;
  --font-sans: Inter, "SF Pro Display", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  --font-mono: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
}

:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #090b10;
  --wash: #0d1017;
  --panel: #10131a;
  --panel-2: #151922;
  --border: #242933;
  --border-strong: #363d4a;
  --text: #c7cad1;
  --heading: #f4f5f7;
  --muted: #8d929d;
  --brand: #5b7cff;
  --brand-strong: #7792ff;
  --brand-soft: #121c3b;
  --brand-rgb: 91, 124, 255;
}


* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 15px/1.6 var(--font-sans);
  -webkit-font-smoothing: antialiased;
}
button, a { font: inherit; }
a { color: inherit; text-decoration: none; }
button { color: inherit; }
.shell { width: min(1180px, calc(100% - 48px)); margin: 0 auto; }
.hairline { border-color: var(--border); }

.site-header {
  position: fixed; inset: 0 0 auto; z-index: 30;
  border-bottom: 1px solid transparent;
  transition: background .2s ease, border-color .2s ease;
}
.site-header.scrolled {
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  border-color: var(--border);
  backdrop-filter: blur(16px);
}
.nav { height: 68px; display: flex; align-items: center; gap: 34px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--heading); font-weight: 680; font-size: 18px; letter-spacing: -.03em; }
.brand-mark { width: 25px; height: 25px; color: var(--brand); }
.nav-links { display: flex; gap: 30px; margin: 0 auto; color: var(--muted); font-size: 13px; }
.nav-links a:hover { color: var(--heading); }
.nav-actions { display: flex; align-items: center; gap: 9px; }
.nav-actions .btn {
  width: auto; min-height: 32px; padding: 0 12px; font-size: 12px; gap: 6px;
}
.nav-actions .btn svg { width: 12px; height: 12px; }
.theme-toggle {
  width: 36px; height: 36px; border: 0; background: transparent; border-radius: 8px;
  display: grid; place-items: center; cursor: pointer; color: var(--muted);
  transition: color .15s ease, background .15s ease;
}
.theme-toggle:hover { background: var(--wash); color: var(--heading); }
.theme-toggle:focus-visible { outline: none; box-shadow: 0 0 0 3px var(--focus-ring); }
.theme-toggle svg { width: 16px; height: 16px; }
.language-link {
  min-width: 34px; height: 34px; padding: 0 8px; border-radius: 8px;
  display: grid; place-items: center; color: var(--muted); font: 11px var(--font-mono);
}
.language-link:hover { background: var(--wash); color: var(--heading); }
.btn {
  min-height: 38px; padding: 0 17px; border: 1px solid var(--border-strong); border-radius: 8px;
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  color: var(--heading); background: var(--panel); font-size: 13px; font-weight: 570;
  transition: transform .15s ease, background .15s ease, border-color .15s ease;
}
.btn:hover { transform: translateY(-1px); border-color: var(--muted); }
.btn-primary { color: var(--on-brand); background: var(--brand); border-color: var(--brand); }
.btn-primary:hover { background: var(--brand-strong); border-color: var(--brand-strong); }
.btn svg { width: 14px; height: 14px; }

.hero {
  min-height: 860px; position: relative; overflow: hidden;
  border-bottom: 1px solid var(--border);
  display: grid; align-items: start;
}
.hero::before {
  content: ""; position: absolute; inset: 0; z-index: 1; pointer-events: none;
  background:
    radial-gradient(ellipse 54% 48% at 50% 33%, color-mix(in srgb, var(--bg) 94%, transparent) 0%, color-mix(in srgb, var(--bg) 42%, transparent) 62%, transparent 100%),
    linear-gradient(to bottom, var(--bg) 0%, transparent 24%, transparent 76%, var(--bg) 100%);
}
.hero-grid {
  position: absolute; inset: 0; z-index: 2; pointer-events: none;
  width: min(1180px, calc(100% - 48px)); margin: auto;
  border-left: 1px solid var(--border); border-right: 1px solid var(--border);
}
.hero-grid::before, .hero-grid::after {
  content: ""; position: absolute; top: 68px; bottom: 0; width: 1px; background: var(--border);
  opacity: .42;
}
.hero-grid::before { left: 25%; }
.hero-grid::after { right: 25%; }
.hero-content { position: relative; z-index: 3; text-align: center; padding-top: 176px; pointer-events: none; }
.hero-content a { pointer-events: auto; }
.eyebrow {
  display: inline-flex; align-items: center; gap: 8px; margin-bottom: 20px;
  color: var(--brand); font-size: 12px; font-weight: 620; letter-spacing: .02em;
}
.eyebrow::before { content: ""; width: 18px; height: 1px; background: currentColor; }
h1 {
  max-width: 780px; margin: 0 auto; color: var(--heading);
  font-size: clamp(49px, 6vw, 76px); line-height: 1.1; letter-spacing: -.062em; font-weight: 650;
}
.locale-en h1 { max-width: 940px; font-size: clamp(48px, 5.8vw, 72px); }
.title-line { white-space: nowrap; }
h1 .accent {
  color: var(--brand); font-weight: 560;
  text-shadow: 0 0 32px rgba(var(--brand-rgb), .16);
}
.hero-copy { max-width: 640px; margin: 25px auto 0; color: var(--muted); font-size: 16px; line-height: 1.65; }
.hero-actions { margin-top: 30px; display: flex; justify-content: center; gap: 10px; }
.principle {
  margin: 38px auto 0; display: inline-flex; gap: 10px; align-items: center;
  color: var(--muted); font: 11px/1.4 var(--font-mono); letter-spacing: .01em;
}
.principle .status { width: 6px; height: 6px; border-radius: 50%; background: var(--brand); box-shadow: 0 0 0 4px rgba(var(--brand-rgb), .1); }
.product-window {
  position: relative; z-index: 4;
  width: min(940px, calc(100% - 72px)); height: 350px; overflow: hidden;
  margin: 72px auto -118px;
  border: 1px solid var(--border-strong); border-radius: 13px 13px 0 0;
  background: color-mix(in srgb, var(--panel) 94%, transparent);
  box-shadow: 0 18px 70px rgba(9, 18, 38, .12);
  backdrop-filter: blur(14px);
}
.window-bar { height: 43px; display: flex; align-items: center; gap: 6px; padding: 0 14px; border-bottom: 1px solid var(--border); }
.window-dot { width: 7px; height: 7px; border-radius: 50%; background: var(--border-strong); }
.window-title { margin-left: 10px; color: var(--muted); font: 10px var(--font-mono); }
.knowledge-ui { display: grid; grid-template-columns: 190px 1fr; height: calc(100% - 43px); }
.ui-side { padding: 16px 12px; border-right: 1px solid var(--border); background: color-mix(in srgb, var(--wash) 72%, transparent); }
.ui-label { color: var(--muted); font-size: 9px; text-transform: uppercase; letter-spacing: .1em; margin: 4px 8px 9px; }
.ui-row { padding: 7px 9px; border-radius: 6px; font-size: 11px; color: var(--muted); margin-bottom: 2px; }
.ui-row.active { color: var(--brand); background: var(--brand-soft); }
.ui-main { padding: 20px 22px; }
.ui-head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
.ui-head strong { color: var(--heading); font-size: 13px; }
.ui-chip { border: 1px solid var(--border); border-radius: 999px; padding: 3px 8px; color: var(--muted); font-size: 9px; }
.brain-map { position: relative; height: 205px; border: 1px solid var(--border); border-radius: 9px; overflow: hidden; background-image: radial-gradient(var(--border) .7px, transparent .7px); background-size: 15px 15px; }
.map-line { position: absolute; height: 1px; transform-origin: left; background: color-mix(in srgb, var(--brand) 38%, var(--border)); }
.map-node {
  position: absolute; min-width: 105px; padding: 9px 11px; border: 1px solid var(--border-strong);
  background: var(--panel); border-radius: 7px; color: var(--heading); font-size: 10px;
}
.map-node small { display: block; color: var(--muted); font: 8px var(--font-mono); margin-top: 2px; }
.node-center { left: 41%; top: 40%; border-color: var(--brand); box-shadow: 0 0 0 3px rgba(var(--brand-rgb), .08); }
.node-a { left: 8%; top: 16%; }.node-b { right: 7%; top: 13%; }.node-c { left: 12%; bottom: 11%; }.node-d { right: 9%; bottom: 12%; }
.line-a { width: 35%; left: 18%; top: 31%; transform: rotate(20deg); }
.line-b { width: 33%; left: 51%; top: 47%; transform: rotate(-24deg); }
.line-c { width: 32%; left: 20%; top: 73%; transform: rotate(-22deg); }
.line-d { width: 31%; left: 52%; top: 57%; transform: rotate(24deg); }

.tech-strip { border-bottom: 1px solid var(--border); }
.tech-inner { min-height: 116px; display: grid; grid-template-columns: 1.2fr repeat(6, 1fr); align-items: stretch; border-left: 1px solid var(--border); }
.tech-inner > * { border-right: 1px solid var(--border); display: grid; place-items: center; }
.tech-title { padding: 0 22px; color: var(--muted); font: 10px var(--font-mono); text-transform: uppercase; letter-spacing: .08em; text-align: center; }
.tech-name { color: var(--heading); font-weight: 620; font-size: 13px; letter-spacing: -.02em; }

.section { border-bottom: 1px solid var(--border); }
.section-head { text-align: center; padding: 112px 24px 58px; }
.kicker { color: var(--brand); font: 11px var(--font-mono); margin-bottom: 13px; }
h2 { margin: 0; color: var(--heading); font-size: clamp(32px, 4vw, 48px); line-height: 1.08; letter-spacing: -.045em; font-weight: 610; }
.section-head p { max-width: 590px; margin: 17px auto 0; color: var(--muted); }

.workflow-grid { display: grid; grid-template-columns: 1fr 1.35fr; border: 1px solid var(--border); border-bottom: 0; }
.workflow-tabs { border-right: 1px solid var(--border); }
.workflow-tab {
  padding: 29px 32px; border-bottom: 1px solid var(--border); cursor: pointer;
  position: relative; transition: background .15s ease;
}
.workflow-tab:last-child { border-bottom: 0; }
.workflow-tab:hover, .workflow-tab.active { background: var(--wash); }
.workflow-tab.active::before { content: ""; position: absolute; inset: 0 auto 0 -1px; width: 2px; background: var(--brand); }
.workflow-tab strong { display: block; color: var(--heading); font-size: 14px; font-weight: 590; }
.workflow-tab p { margin: 7px 0 0; color: var(--muted); font-size: 12px; line-height: 1.55; }
.workflow-visual { min-height: 390px; padding: 42px; display: grid; place-items: center; background: linear-gradient(135deg, transparent, color-mix(in srgb, var(--brand-soft) 36%, transparent)); }
.code-card { width: 100%; max-width: 520px; border: 1px solid var(--border-strong); border-radius: 10px; overflow: hidden; background: var(--panel); }
.code-top { display: flex; justify-content: space-between; padding: 11px 14px; border-bottom: 1px solid var(--border); color: var(--muted); font: 9px var(--font-mono); }
.code-body { min-height: 198px; padding: 20px; margin: 0; color: var(--text); font: 11px/1.9 var(--font-mono); white-space: pre-wrap; transition: opacity .15s ease; }
.code-body .blue { color: var(--brand); }.code-body .dim { color: var(--muted); }

.feature-grid { display: grid; grid-template-columns: repeat(2, 1fr); border-left: 1px solid var(--border); border-top: 1px solid var(--border); }
.feature {
  min-height: 245px; padding: 36px; border-right: 1px solid var(--border); border-bottom: 1px solid var(--border);
  transition: background .2s ease;
}
.feature:hover { background: var(--wash); }
.feature-icon { width: 34px; height: 34px; border: 1px solid var(--border-strong); border-radius: 8px; display: grid; place-items: center; color: var(--brand); margin-bottom: 30px; }
.feature-icon svg { width: 16px; height: 16px; }
.feature h3 { margin: 0; color: var(--heading); font-size: 17px; font-weight: 590; letter-spacing: -.02em; }
.feature p { max-width: 430px; margin: 10px 0 0; color: var(--muted); font-size: 13px; }
.feature-tag { display: inline-block; margin-top: 20px; color: var(--brand); font: 10px var(--font-mono); }

.security { display: grid; grid-template-columns: 1fr 1fr; align-items: center; min-height: 520px; }
.security-copy { padding: 72px 70px 72px 0; }
.security-copy h2 { font-size: 42px; }
.security-copy > p { color: var(--muted); margin: 18px 0 28px; }
.security-list { display: grid; gap: 15px; }
.security-item { display: flex; gap: 12px; color: var(--text); font-size: 13px; }
.check { color: var(--brand); }
.security-art { align-self: stretch; border-left: 1px solid var(--border); display: grid; place-items: center; padding: 48px; }
.rings { width: min(360px, 100%); aspect-ratio: 1; border: 1px solid var(--border); border-radius: 50%; display: grid; place-items: center; position: relative; }
.rings::before { content: ""; width: 70%; aspect-ratio: 1; border: 1px solid var(--border-strong); border-radius: 50%; position: absolute; }
.rings::after { content: ""; width: 42%; aspect-ratio: 1; background: var(--brand-soft); border: 1px solid rgba(var(--brand-rgb), .35); border-radius: 50%; position: absolute; }
.lock { z-index: 1; width: 38px; height: 38px; color: var(--brand); }
.orbit { position: absolute; width: 8px; height: 8px; border-radius: 50%; background: var(--brand); top: 11%; left: 28%; box-shadow: 0 0 0 5px rgba(var(--brand-rgb), .1); }

.cta { padding: 110px 24px; text-align: center; position: relative; overflow: hidden; }
.cta::before { content: ""; position: absolute; width: 480px; height: 220px; left: 50%; top: 50%; transform: translate(-50%, -50%); background: rgba(var(--brand-rgb), .09); filter: blur(70px); pointer-events: none; }
.cta > * { position: relative; }
.cta p { color: var(--muted); margin: 17px auto 27px; }
.footer { min-height: 150px; border-top: 1px solid var(--border); display: flex; align-items: center; justify-content: space-between; color: var(--muted); font-size: 12px; }
.footer-links { display: flex; gap: 24px; }
.footer a:hover { color: var(--heading); }

@media (max-width: 800px) {
  .shell { width: min(100% - 32px, 680px); }
  .nav { height: 60px; gap: 12px; }
  .nav-links { display: none; }
  .nav-actions { margin-left: auto; }
  .nav-actions .btn { min-height: 30px; padding: 0 10px; }
  .hero { min-height: 780px; }
  .hero-grid { width: calc(100% - 32px); }
  .hero-content { padding: 142px 20px 0; }
  h1 { font-size: clamp(43px, 13vw, 63px); }
  .hero-copy { font-size: 14px; }
  .product-window { bottom: auto; width: calc(100% - 32px); height: 310px; margin: 56px auto -80px; }
  .knowledge-ui { grid-template-columns: 115px 1fr; }
  .ui-side { padding: 12px 7px; }
  .ui-main { padding: 15px; }
  .map-node { min-width: 76px; padding: 7px; font-size: 8px; }
  .tech-inner { grid-template-columns: repeat(3, 1fr); }
  .tech-title { grid-column: 1 / -1; min-height: 55px; border-bottom: 1px solid var(--border); }
  .tech-name { min-height: 58px; }
  .section-head { padding: 84px 16px 42px; }
  .workflow-grid, .security { grid-template-columns: 1fr; }
  .workflow-tabs { border-right: 0; }
  .workflow-visual { min-height: 320px; padding: 22px; border-top: 1px solid var(--border); }
  .feature-grid { grid-template-columns: 1fr; }
  .feature { min-height: auto; padding: 30px 26px; }
  .security-copy { padding: 72px 8px 48px; }
  .security-copy h2 { font-size: 36px; }
  .security-art { min-height: 400px; border-left: 0; border-top: 1px solid var(--border); }
  .footer { align-items: flex-start; flex-direction: column; justify-content: center; gap: 18px; }
}

@media (max-width: 470px) {
  .brand span { display: none; }
  .title-line { white-space: normal; }
  .hero-actions { flex-direction: column; align-items: stretch; padding: 0 25px; }
  .principle { max-width: 280px; text-align: left; }
  .ui-side { display: none; }
  .knowledge-ui { grid-template-columns: 1fr; }
  .window-title { overflow: hidden; white-space: nowrap; text-overflow: ellipsis; }
  .tech-inner { grid-template-columns: repeat(2, 1fr); }
  .workflow-tab { padding: 24px; }
  .security-art { padding: 35px; min-height: 340px; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
}

/* Login card modal */
.login-overlay {
  position: fixed; inset: 0; z-index: 80;
  display: grid; place-items: center; padding: 24px;
  background: color-mix(in srgb, var(--heading) 28%, transparent);
  backdrop-filter: blur(8px);
  opacity: 0; pointer-events: none; transition: opacity .2s ease;
}
.login-overlay.open { opacity: 1; pointer-events: auto; }
.login-card {
  width: min(400px, 100%);
  background: var(--panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 28px 24px 22px;
  box-shadow: 0 24px 64px color-mix(in srgb, var(--heading) 18%, transparent);
  transform: translateY(10px) scale(.98);
  transition: transform .22s ease;
  position: relative;
}
.login-overlay.open .login-card { transform: none; }
.login-card .brand { margin-bottom: 14px; font-size: 16px; }
.login-card h2 { margin: 0 0 6px; font-size: 20px; letter-spacing: -.02em; color: var(--heading); }
.login-card .login-sub { margin: 0 0 16px; color: var(--muted); font-size: 13px; line-height: 1.5; }
.login-card label { display: block; font-size: 12px; color: var(--muted); margin: 10px 0 4px; }
.login-card input {
  width: 100%; height: 36px; padding: 0 12px; border-radius: 8px;
  border: 1px solid var(--border-strong); background: var(--panel); color: var(--heading);
  font: inherit; font-size: 14px; outline: none;
}
.login-card input:focus { border-color: var(--brand); box-shadow: 0 0 0 3px var(--focus-ring); }
.login-card .turnstile-slot { min-height: 65px; margin: 4px 0 8px; display: flex; justify-content: center; }
.login-card .login-submit {
  width: 100%; height: 38px; margin-top: 14px; border: 0; border-radius: 8px;
  background: var(--brand); color: #fff; font-weight: 600; cursor: pointer;
}
.login-card .login-submit:hover { filter: brightness(.95); }
.login-card .login-submit:disabled { opacity: .55; cursor: not-allowed; }
.login-card .login-divider {
  display: flex; align-items: center; gap: 12px; margin: 16px 0 4px;
  color: var(--muted); font-size: 12px;
}
.login-card .login-divider::before, .login-card .login-divider::after {
  content: ""; flex: 1; height: 1px; background: var(--border);
}
.login-card .google-button-host {
  width: 340px; max-width: 100%; min-height: 40px; margin: 10px auto 0;
  display: flex; justify-content: center; color-scheme: light;
}
.login-card .login-legal { margin: 14px 0 0; text-align: center; color: var(--muted); font-size: 11.5px; line-height: 1.45; }
.login-card .login-switch { margin: 14px 0 0; text-align: center; color: var(--muted); font-size: 12.5px; }
.login-card .login-switch a { color: var(--brand); }
.login-card .login-msg { margin: 10px 0 0; padding: 8px 10px; border-radius: 8px; font-size: 12.5px; }
.login-card .login-msg.err { background: #fbe2e2; color: #bd2528; }
.login-card .login-close {
  position: absolute; top: 12px; right: 12px; width: 32px; height: 32px;
  border: 0; border-radius: 8px; background: transparent; color: var(--muted); cursor: pointer;
}
.login-card .login-close:hover { background: var(--wash); color: var(--heading); }