:root {
  --bg: #f6f7f9; --surface: #ffffff; --alt: #eef1f6; --text: #1a1d23; --muted: #4f5a69; --border: #d3d9e1;
  --accent: #2457d6; --accent-hover: #1b46b0; --accent-contrast: #ffffff; --warn-bg: #fcefcf; --warn: #6f4a00;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f1216; --surface: #171b21; --alt: #141920; --text: #e8ebf0; --muted: #a9b3c1; --border: #2d3540;
    --accent: #7ba2ff; --accent-hover: #9bb9ff; --accent-contrast: #0b1220; --warn-bg: #33290f; --warn: #f0c15a;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif; line-height: 1.6; font-size: 16px; }
a { color: var(--accent); }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.skip { position: absolute; left: -999px; top: 0; background: var(--accent); color: var(--accent-contrast); padding: 8px 12px; z-index: 20; }
.skip:focus { left: 8px; top: 8px; }
.wrap { width: 100%; max-width: 1040px; margin: 0 auto; padding: 0 16px; }
.icon { flex: none; }

.site-header { position: sticky; top: 0; z-index: 10; background: var(--surface); border-bottom: 1px solid var(--border); }
.bar { display: flex; align-items: center; gap: 16px; min-height: 60px; flex-wrap: wrap; }
.brand { display: inline-flex; align-items: center; gap: 8px; font-weight: 700; font-size: 1.15rem; color: var(--text); text-decoration: none; margin-right: auto; }
.bar nav { display: flex; gap: 14px; }
.bar nav a { color: var(--muted); text-decoration: none; }
.bar nav a:hover { color: var(--text); }
@media (max-width: 640px) { .bar nav { display: none; } }

.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 44px; padding: 0 20px; border-radius: 10px; font-weight: 600; text-decoration: none; border: 1px solid transparent; }
.btn-primary { background: var(--accent); color: var(--accent-contrast); }
.btn-primary:hover { background: var(--accent-hover); }
.btn-disabled { background: var(--alt); color: var(--muted); border-color: var(--border); }
.badge { display: inline-block; padding: 4px 12px; border-radius: 999px; background: var(--alt); border: 1px solid var(--border); color: var(--muted); font-weight: 600; font-size: 0.9rem; }

.hero { padding: 56px 0 40px; background: linear-gradient(180deg, var(--alt), var(--bg)); }
.hero h1 { font-size: clamp(1.9rem, 5vw, 3rem); line-height: 1.15; margin: 0 0 16px; max-width: 18ch; }
.lead { font-size: 1.15rem; color: var(--muted); max-width: 60ch; margin: 0 0 24px; }
.cta { display: flex; gap: 12px; align-items: center; flex-wrap: wrap; }

.section { padding: 48px 0; }
.section.alt { background: var(--alt); }
.section h2 { font-size: 1.6rem; margin: 0 0 20px; }
.steps { list-style: none; margin: 0; padding: 0; display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.step { display: flex; gap: 14px; align-items: flex-start; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 16px; }
.step-n { flex: none; width: 32px; height: 32px; border-radius: 50%; background: var(--accent); color: var(--accent-contrast); display: inline-flex; align-items: center; justify-content: center; font-weight: 700; }
.step h3, .feature h3 { margin: 0 0 4px; font-size: 1.05rem; }
.step p, .feature p { margin: 0; color: var(--muted); }

.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); }
.card { background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 18px; }
.feature .icon { color: var(--accent); margin-bottom: 8px; }

.chat { max-width: 520px; display: flex; flex-direction: column; gap: 8px; }
.bubble { max-width: 85%; padding: 10px 14px; border-radius: 16px; border: 1px solid var(--border); background: var(--surface); }
.bubble-user { align-self: flex-end; background: var(--accent); color: var(--accent-contrast); border-color: var(--accent); border-bottom-right-radius: 4px; }
.bubble-bot { align-self: flex-start; border-bottom-left-radius: 4px; }

.tiles { list-style: none; margin: 16px 0 0; padding: 0; display: grid; gap: 12px; grid-template-columns: repeat(auto-fit, minmax(130px, 1fr)); }
.tile { display: flex; align-items: center; gap: 10px; background: var(--surface); border: 1px solid var(--border); border-radius: 12px; padding: 14px; }
.tile .icon { color: var(--accent); }

.list { margin: 0; padding-left: 20px; display: grid; gap: 6px; }
.faq-item { background: var(--surface); border: 1px solid var(--border); border-radius: 10px; padding: 12px 16px; margin-bottom: 10px; }
.faq-item summary { cursor: pointer; font-weight: 600; }
.faq-item p { margin: 8px 0 0; color: var(--muted); }

.site-footer { border-top: 1px solid var(--border); background: var(--surface); padding: 24px 0; color: var(--muted); font-size: 0.95rem; }
.site-footer nav { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 8px; }
.site-footer p { margin: 0; }

.prose { max-width: 760px; }
.prose h1 { font-size: 2rem; margin-top: 0; }
.prose h2 { font-size: 1.25rem; margin: 28px 0 8px; }
.prose ul { padding-left: 20px; }
.draft { background: var(--warn-bg); color: var(--warn); border: 1px solid var(--warn); border-radius: 10px; padding: 10px 14px; margin-bottom: 20px; font-weight: 600; }

.notfound { display: flex; min-height: 100vh; align-items: center; justify-content: center; text-align: center; }
.notfound-box h1 { font-size: 3rem; margin: 0 0 8px; }
.notfound-box p { color: var(--muted); margin: 0; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }