:root { --bg: #ffffff; --ink: #1d2330; --muted: #5b6475; --line: #e3e6ec; --accent: #1f5eff; --soft: #f4f6fb; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --bg: #12151b; --ink: #e8ebf1; --muted: #9aa3b5; --line: #2b313d; --accent: #6f94ff; --soft: #1b1f27; } }
* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif; }
a { color: var(--accent); }
header, footer { border-color: var(--line); }
header { border-bottom: 1px solid var(--line); }
header .in, main, footer .in { max-width: 760px; margin: 0 auto; padding: 0 16px; }
header .in { display: flex; align-items: center; gap: 10px; height: 60px; }
header .brand { font-weight: 800; font-size: 19px; color: var(--ink); text-decoration: none; letter-spacing: -.01em; }
header .dot { width: 26px; height: 26px; border-radius: 7px; background: var(--accent); display: inline-block; }
header nav { margin-left: auto; display: flex; gap: 14px; font-size: 14px; }
main { padding-top: 32px; padding-bottom: 48px; }
h1 { font-size: 30px; line-height: 1.2; margin: 0 0 8px; letter-spacing: -.02em; }
h2 { font-size: 19px; margin: 28px 0 6px; }
p, li { color: var(--ink); }
.muted { color: var(--muted); }
.lead { font-size: 19px; color: var(--muted); margin: 0 0 24px; }
.cards { display: grid; grid-template-columns: repeat(auto-fit, minmax(200px, 1fr)); gap: 12px; margin: 24px 0; }
.card { background: var(--soft); border-radius: 14px; padding: 16px; }
.card b { display: block; margin-bottom: 4px; }
footer { border-top: 1px solid var(--line); font-size: 14px; color: var(--muted); }
footer .in { padding-top: 18px; padding-bottom: 24px; display: flex; flex-wrap: wrap; gap: 8px 16px; }

/* home */
.logo { width: 30px; height: 30px; display: block; }
.hero { display: grid; grid-template-columns: 1.1fr .9fr; gap: 40px; align-items: center; padding: 24px 0 8px; }
@media (max-width: 760px) { .hero { grid-template-columns: 1fr; gap: 28px; } }
.hero h1 { font-size: 40px; line-height: 1.1; }
@media (max-width: 760px) { .hero h1 { font-size: 32px; } }
.cta { display: inline-block; background: var(--accent); color: #fff; text-decoration: none; font-weight: 600; padding: 12px 20px; border-radius: 12px; }
.cta:hover { filter: brightness(1.08); }
.chat { background: var(--soft); border: 1px solid var(--line); border-radius: 20px; padding: 16px; display: flex; flex-direction: column; gap: 8px; box-shadow: 0 12px 40px rgba(31, 94, 255, .12); }
.chat .top { font-size: 13px; color: var(--muted); display: flex; align-items: center; gap: 8px; padding-bottom: 6px; border-bottom: 1px solid var(--line); margin-bottom: 4px; }
.chat .top i { width: 8px; height: 8px; border-radius: 50%; background: #22c55e; display: inline-block; }
.msg { max-width: 85%; padding: 9px 12px; border-radius: 16px; font-size: 14.5px; line-height: 1.4; }
.msg.in { background: var(--bg); border: 1px solid var(--line); align-self: flex-start; border-bottom-left-radius: 6px; }
.msg.out { background: var(--accent); color: #fff; align-self: flex-end; border-bottom-right-radius: 6px; }
.msg .t { display: block; font-size: 11px; opacity: .7; margin-top: 2px; }
.section { margin-top: 48px; }
.section h2 { font-size: 24px; margin: 0 0 14px; }
.steps { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; counter-reset: step; }
@media (max-width: 760px) { .steps { grid-template-columns: 1fr; } }
.steps .card::before { counter-increment: step; content: counter(step); display: inline-grid; place-items: center; width: 28px; height: 28px; border-radius: 50%; background: var(--accent); color: #fff; font-weight: 700; font-size: 14px; margin-bottom: 8px; }
.band { margin-top: 48px; background: var(--soft); border-radius: 20px; padding: 28px; text-align: center; }
.band h2 { margin: 0 0 8px; font-size: 24px; }
header .in, main, footer .in { max-width: 980px; }
.doc { max-width: 720px; }
.doc h2 { margin-top: 32px; }
.doc ul { padding-left: 20px; }