:root {
  color-scheme: dark;
  --bg: #090b12;
  --panel: rgba(17, 24, 39, 0.78);
  --panel-strong: rgba(31, 41, 55, 0.88);
  --text: #edf2ff;
  --muted: #9aa8c4;
  --line: rgba(148, 163, 184, 0.18);
  --accent: #8b5cf6;
  --accent-2: #06b6d4;
  --good: #34d399;
  --code: #111827;
  --shadow: 0 24px 70px rgba(0, 0, 0, 0.38);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }
html { min-height: 100%; background: var(--bg); }
body {
  min-height: 100vh;
  margin: 0;
  color: var(--text);
  background:
    radial-gradient(circle at top left, rgba(139, 92, 246, 0.28), transparent 36rem),
    radial-gradient(circle at 85% 10%, rgba(6, 182, 212, 0.20), transparent 30rem),
    linear-gradient(135deg, #080a10 0%, #101827 100%);
}
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  background-image: linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px), linear-gradient(90deg, rgba(255,255,255,0.025) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: linear-gradient(to bottom, black, transparent 85%);
}

button, .upload {
  appearance: none;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.07);
  color: var(--text);
  cursor: pointer;
  font: inherit;
  padding: 0.72rem 1rem;
  transition: transform .16s ease, border-color .16s ease, background .16s ease, color .16s ease;
}
button:hover, .upload:hover { transform: translateY(-1px); border-color: rgba(139, 92, 246, .62); background: rgba(139, 92, 246, .16); }
button:active, .upload:active { transform: translateY(0); }
button.copied, .copy-btn.copied, .copy-chip.copied { color: #06120d; background: var(--good); border-color: transparent; }

.shell { width: min(1480px, calc(100vw - 32px)); margin: 0 auto; padding: 34px 0; position: relative; }
.hero { display: grid; grid-template-columns: minmax(0, 1fr) 280px; gap: 24px; align-items: end; margin-bottom: 22px; }
.eyebrow { margin: 0 0 8px; color: #a78bfa; letter-spacing: .16em; text-transform: uppercase; font-size: .78rem; font-weight: 700; }
h1 { font-size: clamp(2rem, 5vw, 4.8rem); line-height: .98; margin: 0; letter-spacing: -0.06em; }
.subtitle { color: var(--muted); font-size: 1.06rem; line-height: 1.8; max-width: 780px; margin: 18px 0 0; }
.hero-card { border: 1px solid var(--line); border-radius: 28px; padding: 22px; background: linear-gradient(135deg, rgba(139, 92, 246, .16), rgba(6, 182, 212, .10)); box-shadow: var(--shadow); }
.hero-card span { color: var(--muted); font-size: .9rem; }
.hero-card strong { display: block; margin: 8px 0; font-size: 1.45rem; }
.hero-card small { color: var(--muted); line-height: 1.6; }

.toolbar { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; margin-bottom: 16px; padding: 12px; border: 1px solid var(--line); border-radius: 26px; background: rgba(9, 11, 18, .58); backdrop-filter: blur(18px); }
.upload input { display: none; }
.upload { background: linear-gradient(135deg, rgba(139, 92, 246, .42), rgba(6, 182, 212, .22)); border-color: rgba(139, 92, 246, .42); font-weight: 700; }
.status { color: var(--muted); margin-left: auto; padding: 0 10px; }

.workspace { display: grid; grid-template-columns: minmax(320px, .86fr) minmax(360px, 1.14fr); gap: 16px; align-items: stretch; }
.workspace.dragging .panel { border-color: rgba(52, 211, 153, .8); box-shadow: 0 0 0 4px rgba(52, 211, 153, .12), var(--shadow); }
.panel { min-height: 68vh; border: 1px solid var(--line); border-radius: 30px; background: var(--panel); box-shadow: var(--shadow); overflow: hidden; backdrop-filter: blur(20px); }
.panel header { display: flex; align-items: center; justify-content: space-between; gap: 16px; padding: 16px 18px; border-bottom: 1px solid var(--line); background: rgba(255,255,255,.035); }
.panel h2 { margin: 0; font-size: 1rem; }
.panel header span { color: var(--muted); font-size: .9rem; text-align: right; }
textarea { width: 100%; height: calc(68vh - 57px); min-height: 560px; resize: vertical; border: 0; outline: 0; padding: 22px; color: #e5e7eb; background: transparent; font: 14.5px/1.72 ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace; }
.preview { height: calc(68vh - 57px); min-height: 560px; overflow: auto; padding: 28px; line-height: 1.75; }
.preview.empty { display: grid; place-items: center; color: var(--muted); text-align: center; }

.md-block { position: relative; margin: 0 0 18px; padding-right: 42px; }
.md-block:hover > .copy-btn, .md-block:focus-within > .copy-btn { opacity: 1; transform: translateY(0); }
.copy-btn { position: absolute; top: 0; right: 0; opacity: .32; transform: translateY(2px); border-radius: 12px; padding: .34rem .52rem; font-size: .78rem; background: rgba(255,255,255,.08); }
.copy-btn:hover { opacity: 1; }
.copy-chip { display: inline-flex; align-items: center; gap: 4px; margin: 0 .04em; padding: .05rem .34rem; border: 1px solid rgba(139, 92, 246, .28); border-radius: 8px; background: rgba(139, 92, 246, .10); color: inherit; line-height: 1.45; vertical-align: baseline; cursor: pointer; }
.copy-chip:hover { border-color: rgba(139, 92, 246, .7); background: rgba(139, 92, 246, .18); }
.copy-chip code { background: transparent; padding: 0; }
.copy-chip::after { content: "复制"; opacity: 0; max-width: 0; overflow: hidden; white-space: nowrap; color: var(--muted); font-size: .72em; transition: opacity .16s ease, max-width .16s ease; }
.copy-chip:hover::after { opacity: 1; max-width: 3rem; }

.preview h1, .preview h2, .preview h3, .preview h4, .preview h5, .preview h6 { line-height: 1.25; letter-spacing: -0.035em; margin: 1.1em 0 .55em; }
.preview h1 { font-size: 2.4rem; } .preview h2 { font-size: 1.9rem; } .preview h3 { font-size: 1.45rem; }
.preview p { margin: 0 0 1em; color: #dbe4f4; }
.preview a { color: #67e8f9; text-decoration: none; border-bottom: 1px dashed rgba(103, 232, 249, .5); }
.preview a:hover { border-bottom-style: solid; }
.preview code { background: rgba(15, 23, 42, .92); border: 1px solid rgba(148, 163, 184, .20); border-radius: 7px; padding: .12rem .36rem; color: #c4b5fd; font-size: .92em; }
.code-block { padding: 0; border: 1px solid rgba(148, 163, 184, .18); border-radius: 18px; overflow: hidden; background: var(--code); }
.code-meta { display: flex; justify-content: space-between; align-items: center; color: var(--muted); font-size: .8rem; padding: 9px 12px; border-bottom: 1px solid rgba(148, 163, 184, .13); background: rgba(255,255,255,.035); }
.code-block pre { margin: 0; overflow: auto; padding: 18px; }
.code-block code { display: block; background: transparent; border: 0; border-radius: 0; color: #e5e7eb; padding: 0; font-size: .92rem; line-height: 1.65; }
.preview blockquote { margin: 0 0 1em; border-left: 4px solid var(--accent); padding: .7rem 1rem; background: rgba(139, 92, 246, .10); border-radius: 0 16px 16px 0; color: #d8d4ff; }
.preview ul, .preview ol { padding-left: 1.45rem; margin: 0 0 1em; }
.preview li { margin: .32rem 0; }
.preview hr { border: 0; border-top: 1px solid var(--line); margin: 26px 0; }
.preview table { width: 100%; border-collapse: collapse; margin: 0 0 1em; overflow: hidden; border-radius: 14px; }
.preview th, .preview td { border: 1px solid var(--line); padding: .58rem .72rem; text-align: left; }
.preview th { background: rgba(255,255,255,.07); }

.toast { position: fixed; left: 50%; bottom: 24px; transform: translateX(-50%) translateY(20px); opacity: 0; pointer-events: none; border: 1px solid rgba(52, 211, 153, .35); border-radius: 999px; background: rgba(9, 11, 18, .88); color: var(--text); padding: .72rem 1rem; box-shadow: var(--shadow); transition: opacity .18s ease, transform .18s ease; z-index: 20; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (max-width: 920px) {
  .shell { width: min(100% - 20px, 760px); padding: 20px 0; }
  .hero { grid-template-columns: 1fr; }
  .workspace { grid-template-columns: 1fr; }
  .panel, textarea, .preview { min-height: 420px; height: auto; }
  textarea, .preview { height: 58vh; }
  .status { width: 100%; margin-left: 0; }
}