/* ============================================================
   SKYRU AI · 星云湖 (ai.rur1.com) — light theme tokens.
   Derived from the RUR1 site design system (app/globals.css):
   same accent, radii, spacing rhythm and easing — inverted to
   a white surface for the model space.
   ============================================================ */
:root {
  --bg: #ffffff;
  --surface: #f6f8fb;
  --elevated: #ffffff;
  --fg: #0b0e14;
  --muted: #5b6574;
  --accent: #5b8cff;
  /* Darker accent for text/links on white (WCAG AA). */
  --accent-ink: #3061e4;
  --accent-soft: #eef3ff;
  --success: #2f9e63;
  --border: #e3e8f0;
  --shadow: 0 1px 2px rgba(11, 14, 20, 0.04), 0 8px 24px rgba(11, 14, 20, 0.06);

  --font-sans:
    ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto,
    "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", sans-serif;
  --font-mono:
    "JetBrains Mono", ui-monospace, "SF Mono", "Cascadia Mono", Menlo,
    Consolas, monospace;

  --radius-card: 0.875rem; /* 14px */
  --radius-button: 0.625rem; /* 10px */

  --ease-site: cubic-bezier(0.22, 1, 0.36, 1);
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  background-color: var(--bg);
  color: var(--fg);
  font-family: var(--font-sans);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  line-height: 1.6;
}

::selection {
  background-color: color-mix(in srgb, var(--accent) 25%, transparent);
}

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 2px;
}

a {
  color: var(--accent-ink);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
  text-underline-offset: 3px;
}

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

/* Light grid backdrop — mirrors .bg-grid on the main site. */
.bg-grid {
  background-image:
    linear-gradient(to right, color-mix(in srgb, var(--border) 55%, transparent) 1px, transparent 1px),
    linear-gradient(to bottom, color-mix(in srgb, var(--border) 55%, transparent) 1px, transparent 1px);
  background-size: 48px 48px;
}

.container {
  width: 100%;
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* ---------- shared header ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.site-header .inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  height: 4rem;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  color: var(--fg);
  font-weight: 600;
  letter-spacing: 0.01em;
}
.brand:hover {
  text-decoration: none;
}
.brand img {
  height: 2rem;
  width: auto;
}
.brand .divider {
  color: var(--border);
  font-weight: 400;
}
.brand .product {
  color: var(--muted);
  font-weight: 500;
  font-size: 0.9375rem;
}
.site-nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
  font-size: 0.9375rem;
}
.site-nav a {
  color: var(--muted);
}
.site-nav a:hover {
  color: var(--fg);
  text-decoration: none;
}
@media (max-width: 760px) {
  .site-nav .hide-mobile {
    display: none;
  }
}

/* ---------- buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  border-radius: var(--radius-button);
  padding: 0.625rem 1.25rem;
  font-size: 0.9375rem;
  font-weight: 600;
  line-height: 1.4;
  border: 1px solid transparent;
  cursor: pointer;
  transition: background-color 160ms var(--ease-site), border-color 160ms var(--ease-site),
    color 160ms var(--ease-site), transform 160ms var(--ease-site);
}
.btn:hover {
  text-decoration: none;
}
.btn-primary {
  background: var(--accent-ink);
  color: #ffffff;
}
.btn-primary:hover {
  background: #2452c8;
}
.btn-ghost {
  background: transparent;
  color: var(--fg);
  border-color: var(--border);
}
.btn-ghost:hover {
  border-color: color-mix(in srgb, var(--accent) 50%, var(--border));
  background: var(--accent-soft);
}
.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ---------- badge ---------- */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--border));
  background: var(--accent-soft);
  color: var(--accent-ink);
  border-radius: 999px;
  padding: 0.25rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.02em;
}

/* ---------- shared footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  margin-top: 5rem;
  padding: 2.5rem 0;
  font-size: 0.875rem;
  color: var(--muted);
}
.site-footer .cols {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  justify-content: space-between;
  align-items: flex-start;
}
.site-footer .note {
  max-width: 46rem;
  margin-top: 0.75rem;
}
.site-footer nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}
.site-footer a {
  color: var(--muted);
}
.site-footer a:hover {
  color: var(--fg);
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}