:root {
  color-scheme: light;
  --ink: #16202a;
  --muted: #687482;
  --line: #dfe5eb;
  --surface: #ffffff;
  --background: #f3f6f8;
  --accent: #245b48;
}
* { box-sizing: border-box; }
body { margin: 0; font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif; background: var(--background); color: var(--ink); }
button, input { font: inherit; }
.topbar { min-height: 64px; padding: 12px 28px; background: var(--surface); border-bottom: 1px solid var(--line); display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.brand { font-weight: 750; letter-spacing: .02em; }
.top-actions, .language-form { display: flex; align-items: center; gap: 10px; }
.top-actions form { margin: 0; }
button, .button-link { border: 1px solid var(--line); background: var(--surface); color: var(--ink); border-radius: 8px; padding: 8px 12px; cursor: pointer; text-decoration: none; }
button:hover, .button-link:hover { border-color: var(--accent); }
button.primary, .button-link { background: var(--accent); color: white; border-color: var(--accent); }
.page { width: min(1080px, calc(100% - 32px)); margin: 42px auto; }
.hero { margin-bottom: 26px; }
.hero h1 { margin: 6px 0 10px; font-size: clamp(28px, 4vw, 44px); }
.eyebrow { color: var(--accent); font-weight: 750; letter-spacing: .12em; font-size: 12px; }
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 20px; }
.card, .auth-card { background: var(--surface); border: 1px solid var(--line); border-radius: 14px; padding: 24px; box-shadow: 0 8px 28px rgba(23, 35, 46, .05); }
.auth-card { width: min(440px, 100%); margin: 72px auto; }
.stack-form { display: grid; gap: 10px; }
.stack-form input { width: 100%; border: 1px solid var(--line); border-radius: 8px; padding: 11px 12px; margin-bottom: 8px; }
.muted { color: var(--muted); }
.alert { padding: 10px 12px; margin: 12px 0; border-radius: 8px; background: #fff1f0; border: 1px solid #ffc9c5; }
.badge { display: inline-block; border-radius: 999px; background: #e7f2ed; color: var(--accent); padding: 6px 10px; font-size: 13px; }
ul { padding-left: 20px; }
li { margin: 10px 0; }
@media (max-width: 640px) { .topbar { align-items: flex-start; flex-direction: column; } .top-actions { flex-wrap: wrap; } }