:root {
  color-scheme: dark;
  --bg: #0a1018;
  --bg-soft: #121d2c;
  --panel: rgba(19, 30, 45, 0.93);
  --line: #2d415a;
  --text: #edf4ff;
  --muted: #a7bdd5;
  --accent: #74e3cb;
  --accent-strong: #36c8a9;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font: 16px/1.5 Inter, "Segoe UI", Arial, sans-serif;
  color: var(--text);
  background:
    radial-gradient(circle at 14% 0%, rgba(111, 93, 212, 0.2), transparent 34rem),
    radial-gradient(circle at 90% 12%, rgba(64, 194, 162, 0.17), transparent 31rem),
    linear-gradient(165deg, var(--bg), var(--bg-soft));
}

.shell {
  width: min(1260px, calc(100% - 24px));
  margin: 0 auto;
  padding: 18px 0 30px;
}

.toolbar {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  position: sticky;
  top: 6px;
  z-index: 10;
  padding: 12px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: rgba(9, 16, 24, 0.9);
}

.toolbar a {
  display: inline-block;
  text-decoration: none;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 10px 14px;
  color: var(--text);
  font-weight: 700;
  background: #1a293b;
}

.toolbar a.active,
.toolbar a:hover {
  color: #08261f;
  border-color: var(--accent);
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
}

.panel {
  margin-top: 14px;
  padding: 18px;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--panel);
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(2rem, 4.7vw, 3rem);
  line-height: 1.06;
}

h2 {
  margin: 0 0 8px;
  font-size: clamp(1.25rem, 2.3vw, 1.85rem);
}

p {
  margin: 0;
  color: var(--muted);
}

.cards {
  display: grid;
  gap: 12px;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.card {
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 14px;
  background: #182638;
}

.card h3 {
  margin: 0 0 6px;
  color: var(--text);
}

.card p {
  margin-bottom: 10px;
}

.card a {
  text-decoration: none;
  color: #06251f;
  font-weight: 800;
  border-radius: 8px;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  padding: 8px 12px;
  display: inline-block;
}

.tool-frame-wrap {
  margin-top: 14px;
  border: 1px solid var(--line);
  border-radius: 12px;
  overflow: hidden;
  background: #0a111a;
}

.tool-frame {
  width: 100%;
  height: min(78vh, 980px);
  border: 0;
  display: block;
}