:root {
  --primary: #2563eb;
  --primary-dark: #1d4ed8;
  --primary-light: #eff6ff;
  --text: #1f2937;
  --text-muted: #6b7280;
  --border: #e5e7eb;
  --bg: #f4f6fa;
  --card-bg: #ffffff;
  --error: #dc2626;
  --error-bg: #fef2f2;
  --ok-green: #059669;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 4px 14px rgba(0, 0, 0, 0.06);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Segoe UI", system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* ---------- 顶部 ---------- */
.site-header {
  background: var(--card-bg);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  position: sticky;
  top: 0;
  z-index: 10;
}

.brand {
  font-size: 22px;
  font-weight: 700;
  color: var(--primary-dark);
  padding: 16px 24px 4px;
  max-width: 960px;
  margin: 0 auto;
}

.top-nav {
  display: flex;
  gap: 4px;
  max-width: 960px;
  margin: 0 auto;
  padding: 8px 24px 0;
}

.nav-item {
  display: inline-block;
  padding: 10px 22px 12px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 15px;
  border-bottom: 3px solid transparent;
  border-radius: 8px 8px 0 0;
  transition: color 0.15s, background 0.15s;
}

.nav-item:hover {
  color: var(--primary);
  background: var(--primary-light);
}

.nav-item.active {
  color: var(--primary);
  font-weight: 600;
  border-bottom-color: var(--primary);
}

/* ---------- 主体 ---------- */
.container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 28px 24px 48px;
  flex: 1;
}

.query-card,
.result-card,
.error-card {
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 14px;
  box-shadow: var(--shadow);
  padding: 26px 28px;
  margin-bottom: 20px;
}

.query-card h2 {
  font-size: 20px;
  color: var(--text);
  margin-bottom: 8px;
}

.desc {
  color: var(--text-muted);
  font-size: 14px;
  margin-bottom: 18px;
}

.input-row {
  display: flex;
  gap: 10px;
}

#tolerance-input {
  flex: 1;
  padding: 12px 16px;
  font-size: 16px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  outline: none;
  transition: border-color 0.15s, box-shadow 0.15s;
  font-family: inherit;
}

#tolerance-input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

#query-btn {
  padding: 0 28px;
  font-size: 16px;
  font-weight: 600;
  color: #fff;
  background: var(--primary);
  border: none;
  border-radius: 10px;
  cursor: pointer;
  transition: background 0.15s;
  font-family: inherit;
}

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

#query-btn:active {
  transform: translateY(1px);
}

.examples {
  margin-top: 14px;
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
}

.examples-label {
  font-size: 13px;
  color: var(--text-muted);
}

.chip {
  padding: 4px 12px;
  font-size: 13px;
  color: var(--primary);
  background: var(--primary-light);
  border: 1px solid #dbeafe;
  border-radius: 999px;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s;
  font-family: inherit;
}

.chip:hover {
  background: #dbeafe;
  border-color: var(--primary);
}

/* ---------- 结果 ---------- */
.hidden {
  display: none;
}

.result-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 18px;
}

.designation {
  font-size: 34px;
  font-weight: 700;
  color: var(--text);
  letter-spacing: 1px;
}

.type-badge {
  font-size: 14px;
  font-weight: 600;
  color: #fff;
  padding: 4px 14px;
  border-radius: 999px;
}

.type-badge.hole {
  background: var(--primary);
}

.type-badge.shaft {
  background: var(--ok-green);
}

.result-body {
  display: flex;
  gap: 28px;
  align-items: flex-start;
  flex-wrap: wrap;
}

.result-table {
  border-collapse: collapse;
  min-width: 300px;
  flex: 1;
}

.result-table td {
  padding: 9px 12px;
  font-size: 14.5px;
  border-bottom: 1px solid var(--border);
}

.result-table td:first-child {
  color: var(--text-muted);
  white-space: nowrap;
  width: 130px;
}

.result-table td:last-child {
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  text-align: right;
}

.result-table tr:last-child td {
  border-bottom: none;
}

.result-chart {
  flex: 1;
  min-width: 280px;
}

#tolerance-svg {
  width: 100%;
  height: auto;
  display: block;
}

.notes {
  margin-top: 16px;
  padding: 12px 14px;
  background: #fffbeb;
  border: 1px solid #fde68a;
  border-radius: 10px;
  color: #92400e;
  font-size: 13.5px;
}

.notes p {
  margin: 2px 0;
}

/* ---------- 错误 ---------- */
.error-card {
  background: var(--error-bg);
  border-color: #fecaca;
  color: var(--error);
  font-size: 14.5px;
  padding: 18px 22px;
}

/* ---------- 页脚 ---------- */
.site-footer {
  background: var(--card-bg);
  border-top: 1px solid var(--border);
  padding: 18px 24px;
  text-align: center;
  color: var(--text-muted);
  font-size: 12.5px;
}

.site-footer p {
  margin: 2px 0;
}

/* ---------- 响应式 ---------- */
@media (max-width: 640px) {
  .container {
    padding: 18px 14px 36px;
  }

  .query-card,
  .result-card,
  .error-card {
    padding: 18px 16px;
  }

  .input-row {
    flex-direction: column;
  }

  #query-btn {
    padding: 12px 0;
  }

  .result-body {
    flex-direction: column;
  }
}