:root {
  --bg: #0b0e14;
  --bg-soft: #121722;
  --panel: #151b27;
  --panel-2: #1b2230;
  --border: #28303f;
  --ink: #e6ebf2;
  --ink-soft: #aab4c4;
  --muted: #6f7b8e;
  --accent: #4ade80;
  --accent-2: #38bdf8;
  --warn: #fbbf24;
  --code-bg: #0d1119;
  --radius: 14px;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(1200px 600px at 70% -10%, #16203020, transparent), var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
.wrap { width: min(1120px, 92vw); margin: 0 auto; }

/* topbar */
.topbar {
  position: sticky; top: 0; z-index: 20;
  background: rgba(11, 14, 20, 0.82);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; padding: 14px 0; }
.brand { display: flex; align-items: center; gap: 12px; }
.brand-mark { font-size: 28px; }
.brand-title { font-weight: 700; font-size: 17px; letter-spacing: .3px; }
.brand-sub { font-size: 12px; color: var(--muted); }
.ghost-link { color: var(--accent); text-decoration: none; font-size: 14px; font-weight: 600; border: 1px solid var(--border); padding: 7px 14px; border-radius: 999px; }
.ghost-link:hover { background: var(--panel-2); }

/* hero */
.hero { padding: 54px 0 26px; max-width: 760px; }
.hero h1 { font-size: clamp(26px, 4.5vw, 40px); line-height: 1.2; margin: 0 0 16px; letter-spacing: -.5px; }
.lead { font-size: 17px; color: var(--ink-soft); margin: 0 0 18px; }
.lead strong { color: var(--ink); }
.hero-badges { display: flex; flex-wrap: wrap; gap: 10px; }
.hero-badges span {
  font-size: 12.5px; color: var(--ink-soft);
  background: var(--panel); border: 1px solid var(--border);
  padding: 6px 12px; border-radius: 999px;
}

/* layout */
.layout { display: grid; grid-template-columns: 380px 1fr; gap: 22px; align-items: start; margin-bottom: 40px; }
.panel { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 22px; box-shadow: var(--shadow); }
.config { position: sticky; top: 78px; }
.panel-title { font-size: 15px; margin: 0 0 18px; color: var(--ink); }

/* form */
.field { margin-bottom: 18px; }
.field > label { display: block; font-size: 13px; font-weight: 600; color: var(--ink-soft); margin-bottom: 8px; }
textarea {
  width: 100%; resize: vertical; min-height: 72px;
  background: var(--bg-soft); color: var(--ink);
  border: 1px solid var(--border); border-radius: 10px;
  padding: 11px 12px; font: inherit; font-size: 14px;
}
textarea:focus { outline: none; border-color: var(--accent-2); }
.hint { font-size: 12px; color: var(--muted); margin: 7px 2px 0; line-height: 1.45; }

.seg { display: flex; gap: 6px; }
.seg-wrap { flex-wrap: wrap; }
.seg-btn {
  flex: 1 1 auto; min-width: fit-content;
  background: var(--bg-soft); color: var(--ink-soft);
  border: 1px solid var(--border); border-radius: 9px;
  padding: 8px 10px; font: inherit; font-size: 12.5px; cursor: pointer;
  transition: all .12s ease;
}
.seg-btn:hover { border-color: var(--accent-2); color: var(--ink); }
.seg-btn.on { background: var(--accent); color: #06120a; border-color: var(--accent); font-weight: 700; }

.actions { display: flex; gap: 10px; margin-top: 20px; }
button.primary {
  flex: 1; background: var(--accent); color: #06120a;
  border: none; border-radius: 10px; padding: 12px; font: inherit; font-weight: 700; font-size: 14px; cursor: pointer;
}
button.primary:hover { filter: brightness(1.08); }
button.ghost {
  background: transparent; color: var(--ink-soft);
  border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; font: inherit; font-size: 13px; cursor: pointer;
}
button.ghost:hover { background: var(--panel-2); color: var(--ink); }
button.ghost.sm { padding: 7px 12px; font-size: 12.5px; }
.micro { font-size: 11.5px; color: var(--muted); margin: 12px 2px 0; }

/* result */
.result-head { display: flex; align-items: center; justify-content: space-between; margin-bottom: 6px; }
.result-tools { display: flex; gap: 8px; }
.output { min-height: 320px; }
.empty-state { text-align: center; color: var(--muted); padding: 70px 20px; }
.empty-mark { font-size: 40px; margin-bottom: 12px; }

.note-sec { border-top: 1px solid var(--border); padding: 18px 0; }
.note-sec:first-child { border-top: none; padding-top: 4px; }
.note-sec h3 { font-size: 15px; margin: 0 0 12px; }
.note-sec ul, .note-sec ol { margin: 0; padding-left: 20px; }
.note-sec li { margin-bottom: 6px; color: var(--ink-soft); font-size: 14px; }
.sub-h { font-size: 12.5px; font-weight: 700; color: var(--muted); margin: 14px 0 6px; text-transform: uppercase; letter-spacing: .5px; }
.hypo-echo { font-size: 16px; color: var(--accent-2); background: var(--bg-soft); border-left: 3px solid var(--accent-2); padding: 12px 14px; border-radius: 0 8px 8px 0; margin: 0; }
.hypo-echo.muted { color: var(--muted); border-color: var(--border); }

.card-table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.card-table th, .card-table td { text-align: left; vertical-align: top; padding: 8px 10px; border-bottom: 1px solid var(--border); }
.card-table th { width: 130px; color: var(--muted); font-weight: 600; white-space: nowrap; }
.card-table td { color: var(--ink-soft); }

pre.code {
  background: var(--code-bg); border: 1px solid var(--border); border-radius: 10px;
  padding: 14px; overflow-x: auto; margin: 0 0 8px;
}
pre.code code { font-family: var(--mono); font-size: 12.5px; color: #c8d3e0; line-height: 1.55; white-space: pre; }

/* why */
.why { margin: 10px 0 50px; }
.why h2 { font-size: 20px; margin-bottom: 18px; }
.why-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.why-card { background: var(--panel); border: 1px solid var(--border); border-radius: var(--radius); padding: 20px; }
.why-card h3 { margin: 0 0 8px; font-size: 15px; color: var(--accent); }
.why-card p { margin: 0; font-size: 13.5px; color: var(--ink-soft); }

/* footer */
.foot { border-top: 1px solid var(--border); padding: 26px 0; color: var(--muted); font-size: 13px; }
.foot p { margin: 4px 0; }
.disclaimer { color: var(--warn); font-size: 12px; }

/* responsive */
@media (max-width: 880px) {
  .layout { grid-template-columns: 1fr; }
  .config { position: static; }
  .why-grid { grid-template-columns: 1fr; }
}

/* print */
@media print {
  .topbar, .hero, .why, .foot, .config, .result-tools, .ghost-link { display: none !important; }
  body { background: #fff; color: #000; }
  .layout { display: block; }
  .panel { box-shadow: none; border: none; }
  .note-sec li, .card-table td, .card-table th { color: #000; }
  pre.code { background: #f4f4f4; }
  pre.code code { color: #111; }
}