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

:root {
  --bg: #ffffff;
  --text: #2b2b2b;
  --text-dim: #999999;
  --accent: #2b7de9;
  --accent-hover: #155bb0;
  --border: #eeeeee;
  --divider: #f0f0f0;
}

html, body { height: 100%; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: #ffffff;
  font-size: 15px;
  line-height: 1.7;
}

/* 顶部标题 */
.site-header {
  text-align: center;
  padding: 60px 20px 48px;
}
.site-header h1 {
  font-size: 2.2rem;
  font-weight: 700;
  letter-spacing: 3px;
}
.site-sub {
  margin-top: 12px;
  font-size: 0.95rem;
  color: var(--text-dim);
  letter-spacing: 1px;
}

/* 分类导航 */
.tool-nav {
  max-width: 760px;
  margin: 0 auto 96px;
  padding: 0 24px;
}
.tool-group {
  margin-bottom: 48px;
}
.tool-group h2 {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--divider);
  margin-bottom: 16px;
}
.tool-list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 36px;
}
.tool-entry {
  border: none;
  background: none;
  color: var(--accent);
  font-size: 1rem;
  cursor: pointer;
  padding: 0;
  font-family: inherit;
}
.tool-entry:hover { color: var(--accent-hover); text-decoration: underline; }

/* 工具弹窗 */
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.4);
}
.modal-overlay[hidden] { display: none; }
.tool-view {
  width: min(500px, calc(100vw - 40px));
  max-height: 86vh;
  overflow-y: auto;
  padding: 28px;
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 8px;
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.12);
}
.tool-back {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  margin-bottom: 16px;
  padding: 5px 14px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  color: var(--text);
  font-size: 0.85rem;
  cursor: pointer;
  font-family: inherit;
}
.tool-back:hover { background: #fafafa; }
.tool-pane { min-height: 180px; }

/* 按钮 */
.btn {
  padding: 9px 20px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s;
}
.btn.ghost { background: #fff; color: var(--text); }
.btn.ghost:hover { background: #fafafa; }
.btn.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.btn.primary:hover { background: var(--accent-hover); }

/* 查询输入行 */
.query-row {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}
.query-row input {
  flex: 1;
  min-width: 0;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.95rem;
  outline: none;
  color: var(--text);
  font-family: inherit;
}
.query-row input:focus { border-color: var(--accent); }

/* 查询结果 */
.query-result {
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  line-height: 1.8;
  min-height: 48px;
  word-break: break-all;
  color: var(--text);
}
.query-result .q-row { display: flex; justify-content: space-between; gap: 12px; padding: 1px 0; }
.query-result .q-label { color: var(--text-dim); flex-shrink: 0; }
.query-result .q-val { text-align: right; }
.qr-result { margin-top: 12px; text-align: center; }
.qr-result img { max-width: 220px; border: 1px solid var(--border); border-radius: 4px; padding: 8px; }

/* 计算器 */
.calc-display {
  min-height: 54px;
  padding: 12px 14px;
  margin-bottom: 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 1.5rem;
  font-weight: 600;
  text-align: right;
  overflow-x: auto;
  white-space: nowrap;
}
.calc-keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 6px;
}
.calc-keys button {
  padding: 12px 0;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  color: var(--text);
  font-size: 1rem;
  cursor: pointer;
  font-family: inherit;
  transition: background 0.15s;
}
.calc-keys button:hover { background: #fafafa; }
.calc-keys .calc-op { background: #f4f8fd; color: var(--accent); }
.calc-keys .calc-fn { background: #fafafa; color: var(--text-dim); }
.calc-keys .calc-eq { background: var(--accent); border-color: var(--accent); color: #fff; }
.calc-keys .calc-zero { grid-column: span 2; }

/* 日历 */
.calendar-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
}
.cal-nav {
  width: 34px;
  height: 34px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  color: var(--text);
  cursor: pointer;
  font-size: 1.1rem;
  font-family: inherit;
}
.cal-nav:hover { background: #fafafa; }
.cal-title { font-size: 1rem; font-weight: 600; }
.cal-week {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  margin-bottom: 4px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.75rem;
}
.cal-grid {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 3px;
}
.cal-day, .cal-empty {
  aspect-ratio: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 4px;
  font-size: 0.82rem;
}
.cal-day:hover { background: #fafafa; }
.cal-today { background: var(--accent); color: #fff; font-weight: 600; }

/* 汇率 */
.currency-row {
  display: flex;
  gap: 8px;
  margin-bottom: 8px;
}
.currency-row input, .currency-row select {
  flex: 1;
  padding: 9px 12px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  color: var(--text);
  font-size: 0.95rem;
  font-family: inherit;
}
.currency-swap {
  text-align: center;
  margin: 4px 0;
  color: var(--accent);
  font-size: 0.85rem;
  cursor: pointer;
  user-select: none;
}
.currency-note { font-size: 0.75rem; color: var(--text-dim); margin-top: 8px; }

/* 番茄钟 */
.pomodoro-display {
  text-align: center;
  font-size: 2.8rem;
  font-weight: 600;
  margin: 8px 0 16px;
  font-variant-numeric: tabular-nums;
}
.pomodoro-modes {
  display: flex;
  gap: 6px;
  justify-content: center;
  margin-bottom: 16px;
}
.pomodoro-modes button {
  padding: 6px 14px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: #fff;
  color: var(--text-dim);
  font-size: 0.78rem;
  cursor: pointer;
  font-family: inherit;
}
.pomodoro-modes button.pm-active { background: var(--accent); border-color: var(--accent); color: #fff; }
.pomodoro-controls {
  display: flex;
  gap: 10px;
  justify-content: center;
}

/* 随机数 */
.random-fields {
  display: flex;
  gap: 10px;
  margin-bottom: 12px;
}
.random-fields label {
  flex: 1;
  font-size: 0.78rem;
  color: var(--text-dim);
}
.random-fields input {
  width: 100%;
  margin-top: 4px;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  color: var(--text);
  font-family: inherit;
  outline: none;
}
.random-result {
  margin-top: 12px;
  padding: 14px;
  border: 1px solid var(--border);
  border-radius: 4px;
  font-size: 0.9rem;
  word-break: break-all;
  line-height: 1.7;
  min-height: 20px;
}

@media (max-width: 480px) {
  .site-header { padding: 40px 20px 32px; }
  .site-header h1 { font-size: 1.6rem; }
  .tool-list { gap: 10px 24px; }
}