/* Cachet site. Ink, wax and gold; follows the system light/dark setting. No external fonts. */
:root {
  --bg: #faf8f4; --surface: #f2eee7; --surface-2: #eae5dc; --line: #ddd6ca;
  --text: #1c1b1a; --muted: #5e5a52; --wax: #8e2234; --wax-ink: #ffffff; --gold: #8a6a2a;
  --ok: #3f7a2f; --warn: #9a5b12; --danger: #a3283c;
  --serif: "Songti SC", "Noto Serif SC", "Source Han Serif SC", Georgia, "Times New Roman", serif;
  --sans: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Segoe UI", Roboto, sans-serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, monospace;
  --radius: 18px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0f0f11; --surface: #18181b; --surface-2: #212125; --line: #2c2c31;
    --text: #f1efea; --muted: #a19d94; --wax: #a3304a; --gold: #c9a35b;
    --ok: #7cbf68; --warn: #e0a85a; --danger: #e07a88;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; background: var(--bg); color: var(--text); font: 16px/1.7 var(--sans); -webkit-font-smoothing: antialiased; }
a { color: var(--gold); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }
.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* header */
header.top { position: sticky; top: 0; z-index: 10; background: color-mix(in srgb, var(--bg) 88%, transparent); backdrop-filter: blur(10px); border-bottom: 1px solid var(--line); }
header.top .wrap { display: flex; align-items: center; gap: 24px; height: 64px; }
.brand { display: flex; align-items: center; gap: 10px; font: 700 24px/1 var(--serif); color: var(--gold); }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 9px; }
nav.links { display: flex; gap: 20px; margin-left: auto; font-size: 15px; }
nav.links a { color: var(--text); }
@media (max-width: 720px) { nav.links a.hide-sm { display: none; } nav.links { gap: 14px; } }

/* hero */
.hero { padding-top: 72px; padding-bottom: 40px; }
.hero h1 { font: 700 clamp(34px, 6vw, 58px)/1.15 var(--serif); margin: 0 0 18px; letter-spacing: .5px; }
.hero h1 em { font-style: normal; color: var(--wax); }
.hero p.lead { font-size: 19px; color: var(--muted); max-width: 640px; margin: 0 0 28px; }
.btns { display: flex; flex-wrap: wrap; gap: 12px; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; height: 48px; padding: 0 22px; border-radius: 999px; border: 1px solid var(--line); background: transparent; color: var(--text); font: 600 16px var(--sans); cursor: pointer; transition: transform .08s, background .15s; }
.btn:hover { text-decoration: none; background: var(--surface); }
.btn:active { transform: scale(.98); }
.btn.primary { background: var(--wax); border-color: var(--wax); color: var(--wax-ink); }
.btn.primary:hover { filter: brightness(1.08); background: var(--wax); }
.btn.gold { color: var(--gold); border-color: color-mix(in srgb, var(--gold) 50%, transparent); }
.btn[disabled] { opacity: .55; cursor: progress; }
.btn.small { height: 36px; padding: 0 14px; font-size: 14px; }

/* sections */
section { padding: 56px 0; }
section h2 { font: 700 32px/1.3 var(--serif); margin: 0 0 10px; }
section p.sub { color: var(--muted); margin: 0 0 32px; max-width: 720px; }
.card { background: var(--surface); border-radius: var(--radius); padding: 24px; }
.grid { display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); }
.grid .card h3 { margin: 6px 0 6px; font-size: 18px; }
.grid .card p { margin: 0; color: var(--muted); font-size: 15px; }
.icon { width: 28px; height: 28px; color: var(--gold); }

/* tool */
.tool { padding: 8px; background: var(--surface); border-radius: 24px; }
.tabs { display: flex; gap: 6px; padding: 6px; }
.tabs button { flex: 1; height: 44px; border: 0; border-radius: 999px; background: transparent; color: var(--muted); font: 600 16px var(--sans); cursor: pointer; }
.tabs button[aria-selected="true"] { background: var(--bg); color: var(--text); box-shadow: 0 1px 2px rgba(0,0,0,.08); }
.pane { padding: 18px 18px 22px; }
.pane[hidden] { display: none; }
label.field { display: block; font-size: 14px; color: var(--muted); margin: 14px 0 6px; }
textarea, input[type=text], input[type=password] { width: 100%; border: 1px solid var(--line); border-radius: 14px; background: var(--bg); color: var(--text); font: 16px/1.6 var(--sans); padding: 12px 14px; outline: none; }
textarea { min-height: 120px; resize: vertical; }
textarea:focus, input:focus { border-color: var(--gold); }
.chips { display: flex; flex-wrap: wrap; gap: 8px; }
.chip { height: 36px; padding: 0 14px; border-radius: 999px; border: 1px solid var(--line); background: var(--bg); color: var(--text); font: 500 14px var(--sans); cursor: pointer; }
.chip[aria-pressed="true"] { background: var(--wax); border-color: var(--wax); color: #fff; }
.row { display: flex; flex-wrap: wrap; gap: 16px; align-items: center; }
.toggle { display: inline-flex; align-items: center; gap: 8px; font-size: 15px; cursor: pointer; user-select: none; }
.toggle input { width: 18px; height: 18px; accent-color: var(--wax); }
.actions { margin-top: 20px; display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.note { font-size: 13px; color: var(--muted); }
.result { margin-top: 18px; border-radius: 16px; background: var(--bg); border: 1px solid var(--line); padding: 16px; }
.result[hidden] { display: none; }
.result .cipher { font: 18px/1.8 var(--serif); word-break: break-all; }
.result .plain { font-size: 18px; white-space: pre-wrap; word-break: break-word; }
.meta { display: flex; flex-wrap: wrap; gap: 8px 16px; margin-top: 12px; font-size: 14px; color: var(--muted); }
.badge { display: inline-flex; align-items: center; gap: 6px; padding: 3px 10px; border-radius: 999px; background: var(--surface-2); font-size: 13px; color: var(--muted); }
.badge.gold { color: var(--gold); }
.badge.danger { color: var(--danger); }
.countdown { font-family: var(--mono); color: var(--gold); }
.error { color: var(--danger); font-size: 15px; margin-top: 12px; }
.error[hidden] { display: none; }

/* how it works */
.steps { counter-reset: s; display: grid; gap: 16px; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.steps .card { position: relative; padding-top: 52px; }
.steps .card::before { counter-increment: s; content: counter(s); position: absolute; top: 18px; left: 24px; width: 26px; height: 26px; border-radius: 50%; background: var(--wax); color: #fff; font: 700 14px/26px var(--sans); text-align: center; }

/* docs */
.doc h2 { margin-top: 40px; }
.doc h3 { margin: 28px 0 8px; font-size: 20px; }
.doc table { width: 100%; border-collapse: collapse; margin: 12px 0 20px; font-size: 15px; }
.doc th, .doc td { text-align: left; padding: 10px 12px; border-bottom: 1px solid var(--line); vertical-align: top; }
.doc th { color: var(--muted); font-weight: 600; }
pre, code { font-family: var(--mono); font-size: 14px; }
pre { background: var(--surface); border-radius: 14px; padding: 16px; overflow-x: auto; line-height: 1.55; }
:not(pre) > code { background: var(--surface-2); padding: 1px 6px; border-radius: 6px; }
.callout { border-left: 3px solid var(--gold); background: var(--surface); padding: 14px 18px; border-radius: 0 12px 12px 0; margin: 16px 0; }
.callout.warn { border-color: var(--warn); }

footer { border-top: 1px solid var(--line); padding: 32px 0 48px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; flex-wrap: wrap; gap: 12px 24px; }
footer .wrap .grow { flex: 1; }