:root {
  --bg: #020b18;
  --panel: rgba(7, 26, 47, 0.88);
  --ink: #e8f8ff;
  --muted: #95c8de;
  --line: rgba(82, 199, 235, 0.34);
  --brand: #2ee6ff;
  --brand-deep: #00b7d1;
  --accent: #20ffd4;
  --quote: rgba(7, 43, 74, 0.78);
  --code: #d8f8ff;
  --code-bg: rgba(30, 71, 103, 0.5);
  --radius: 16px;
  --shadow: 0 18px 42px rgba(0, 8, 20, 0.45);
}

* { box-sizing: border-box; }

body {
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 9% 2%, rgba(32, 255, 212, 0.2), transparent 28%),
    radial-gradient(circle at 84% 12%, rgba(46, 230, 255, 0.24), transparent 30%),
    radial-gradient(circle at 75% 78%, rgba(0, 152, 196, 0.16), transparent 32%),
    linear-gradient(155deg, #03162b 0%, #08274a 44%, #021123 100%);
  font-family: "LXGW WenKai", "Source Han Serif SC", "Noto Serif SC", "PingFang SC", sans-serif;
  line-height: 1.75;
}

.progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 4px;
  width: 100%;
  z-index: 99;
  background: transparent;
}

.progress > span {
  display: block;
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #1bcde8, #32ffe7);
}

.page {
  width: min(1240px, calc(100% - 28px));
  margin: 28px auto 48px;
}

.hero {
  background:
    linear-gradient(130deg, rgba(8, 31, 55, 0.86), rgba(7, 40, 71, 0.8)),
    radial-gradient(circle at 10% 0%, rgba(32, 255, 212, 0.16), transparent 44%);
  border: 1px solid rgba(58, 208, 240, 0.32);
  border-radius: 24px;
  box-shadow: var(--shadow);
  padding: 26px 24px;
  backdrop-filter: blur(2px);
}

.hero h1 {
  margin: 0;
  font-size: clamp(1.9rem, 3.8vw, 2.9rem);
  line-height: 1.25;
}

.hero p {
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 1.04rem;
}

.layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 320px;
  gap: 24px;
  margin-top: 22px;
}

.main {
  min-width: 0;
}

.article {
  background: var(--panel);
  border-radius: 22px;
  border: 1px solid var(--line);
  padding: 22px 24px 34px;
  box-shadow: var(--shadow);
}

.article h1,
.article h2,
.article h3,
.article h4,
.article h5,
.article h6 {
  line-height: 1.35;
  margin-top: 1.2em;
  margin-bottom: 0.48em;
}

.article h1 { font-size: clamp(1.8rem, 3.4vw, 2.4rem); }
.article h2 {
  font-size: clamp(1.34rem, 2.5vw, 1.75rem);
  padding: 8px 12px;
  border-left: 4px solid var(--brand);
  background: rgba(46, 230, 255, 0.14);
  border-radius: 8px;
}
.article h3 { font-size: clamp(1.15rem, 2.2vw, 1.35rem); color: var(--brand); }

.article p {
  margin: 0.45em 0 1em;
  text-wrap: pretty;
}

.article ul,
.article ol {
  margin: 0.45em 0 1em;
  padding-left: 1.4em;
}

.article li { margin: 0.28em 0; }

.article blockquote {
  margin: 1em 0;
  padding: 12px 14px;
  border-radius: 10px;
  background: var(--quote);
  border-left: 4px solid var(--brand);
  color: #c9eeff;
}

.article code {
  font-family: "SFMono-Regular", Menlo, Consolas, monospace;
  font-size: 0.9em;
  padding: 0.1em 0.35em;
  border-radius: 4px;
  background: var(--code-bg);
  color: var(--code);
}

.article pre {
  margin: 0.9em 0 1.2em;
  overflow: auto;
  background: #041125;
  color: #cdefff;
  padding: 14px 16px;
  border-radius: 12px;
  border: 1px solid rgba(74, 201, 235, 0.28);
}

.article pre code {
  background: none;
  color: inherit;
  padding: 0;
  font-size: 0.88rem;
}

.article strong { color: #f1fcff; }

.article hr {
  border: none;
  border-top: 1px dashed rgba(121, 217, 245, 0.5);
  margin: 1.5em 0;
}

.table-wrap { overflow: auto; margin: 0.9em 0 1.2em; }

.article table {
  width: 100%;
  border-collapse: collapse;
  min-width: 620px;
  border: 1px solid var(--line);
  border-radius: 10px;
  overflow: hidden;
}

.article th,
.article td {
  border: 1px solid var(--line);
  padding: 9px 11px;
  text-align: left;
}

.article th {
  background: rgba(46, 230, 255, 0.15);
  color: #e8f9ff;
}

.toc-panel {
  position: sticky;
  top: 18px;
  align-self: start;
  max-height: calc(100vh - 36px);
  overflow: auto;
  background: rgba(6, 20, 38, 0.88);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 12px;
}

.toc-title {
  margin: 0 0 8px;
  font-size: 0.98rem;
  color: var(--muted);
  font-weight: 700;
}

.toc-item {
  display: block;
  text-decoration: none;
  color: #c9ebff;
  padding: 7px 9px;
  border-radius: 9px;
  font-size: 0.92rem;
  line-height: 1.45;
}

.toc-item:hover,
.toc-item.is-active {
  background: rgba(46, 230, 255, 0.2);
}

.toc-sub {
  padding-left: 22px;
  color: #9fd7f2;
  font-size: 0.88rem;
}

.mobile-toggle {
  display: none;
}

@media (max-width: 980px) {
  .layout {
    grid-template-columns: 1fr;
  }

  .mobile-toggle {
    display: inline-block;
    margin-top: 10px;
    border: 0;
    background: linear-gradient(120deg, #00b7d1, #2ee6ff);
    color: #052238;
    padding: 8px 12px;
    border-radius: 8px;
    font-weight: 700;
  }

  .toc-panel {
    position: static;
    max-height: none;
    display: none;
  }

  .toc-panel.open {
    display: block;
  }
}