:root {
  --bg: #f3f6fb;
  --panel: #ffffff;
  --text: #1f2a37;
  --muted: #6b7b8c;
  --line: #dde4ee;
  --primary: #3b6ff5;
  --primary-dark: #2f57c8;
  --shadow: 0 10px 30px rgba(31, 42, 55, 0.08);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: linear-gradient(180deg, #eef3ff 0%, var(--bg) 220px);
}

.hero {
  max-width: 1280px;
  margin: 0 auto;
  padding: 32px 20px 12px;
  display: grid;
  grid-template-columns: 1.4fr 0.8fr;
  gap: 20px;
}

.eyebrow {
  margin: 0 0 8px;
  color: var(--primary);
  font-weight: 600;
}

h1 {
  margin: 0 0 12px;
  font-size: 2.2rem;
}

.lead {
  margin: 0;
  line-height: 1.7;
  color: var(--muted);
}

.hero-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 16px;
  padding: 18px 20px;
  box-shadow: var(--shadow);
}

.hero-card ol {
  margin: 10px 0 0;
  padding-left: 18px;
  line-height: 1.8;
}

.layout {
  max-width: 1280px;
  margin: 0 auto;
  padding: 12px 20px 28px;
  display: grid;
  grid-template-columns: 300px 1fr;
  grid-template-areas:
    "data viz"
    "algo predict";
  gap: 18px;
}

.panel {
  background: var(--panel);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.panel h2 {
  margin: 0 0 8px;
  font-size: 1.15rem;
}

.data-panel { grid-area: data; }
.viz-panel { grid-area: viz; min-height: 520px; }
.algo-panel { grid-area: algo; }
.predict-panel { grid-area: predict; }

.muted {
  color: var(--muted);
  line-height: 1.6;
}

.controls-grid {
  display: grid;
  gap: 12px;
  margin: 14px 0;
}

label {
  display: grid;
  gap: 6px;
  font-size: 0.92rem;
}

input[type="number"],
select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--line);
  border-radius: 10px;
  font: inherit;
}

input[type="range"] {
  width: 100%;
}

.button-row {
  display: flex;
  gap: 10px;
  margin-top: 8px;
}

.btn {
  border: 0;
  border-radius: 10px;
  padding: 10px 14px;
  font: inherit;
  cursor: pointer;
}

.btn.primary {
  background: var(--primary);
  color: #fff;
}

.btn.primary:hover {
  background: var(--primary-dark);
}

.btn.secondary {
  background: #edf2ff;
  color: var(--primary-dark);
}

.metric-box,
.prediction-box,
.tree-box {
  margin-top: 14px;
  padding: 12px;
  background: #f8fafc;
  border-radius: 12px;
  border: 1px solid var(--line);
}

.fruit-legend {
  display: grid;
  gap: 6px;
  margin-top: 14px;
  font-size: 0.9rem;
}

#plot {
  width: 100%;
  height: 460px;
  display: block;
  border-radius: 14px;
  border: 1px solid var(--line);
  background: #fbfcfe;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 14px;
}

.tab {
  border: 1px solid var(--line);
  background: #f8fafc;
  color: var(--text);
  border-radius: 999px;
  padding: 8px 12px;
  cursor: pointer;
  font-size: 0.86rem;
}

.tab.active {
  background: #edf2ff;
  border-color: #b8c9ff;
  color: var(--primary-dark);
  font-weight: 600;
}

.algo-copy h3 {
  margin: 0 0 6px;
}

.tag {
  display: inline-block;
  margin: 0 0 10px;
  padding: 4px 10px;
  border-radius: 999px;
  background: #eef8f1;
  color: #2d6a4f;
  font-size: 0.82rem;
}

.algo-copy blockquote {
  margin: 12px 0 0;
  padding: 12px 14px;
  border-left: 4px solid #ffd166;
  background: #fff9eb;
  color: #6a5b00;
}

.params-box {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}

.param span {
  display: flex;
  justify-content: space-between;
}

.tree-line {
  font-family: Consolas, monospace;
  font-size: 0.86rem;
  line-height: 1.7;
}

.sliders-box {
  display: grid;
  gap: 10px;
  max-height: 420px;
  overflow: auto;
  padding-right: 4px;
}

.slider-row {
  grid-template-columns: 120px 1fr 56px;
  align-items: center;
}

.prediction-card .prediction-main {
  font-size: 1.2rem;
}

.footer {
  max-width: 1280px;
  margin: 0 auto;
  padding: 0 20px 30px;
  color: var(--muted);
}

@media (max-width: 980px) {
  .hero,
  .layout {
    grid-template-columns: 1fr;
    grid-template-areas:
      "data"
      "viz"
      "algo"
      "predict";
  }

  #plot {
    height: 360px;
  }
}