/* ===== CSS变量 ===== */
:root {
  --bg: #f0f2f5;
  --bg2: #ffffff;
  --bg3: #f7f8fa;
  --border: #e4e7ed;
  --text: #303133;
  --text2: #606266;
  --text3: #909399;
  --primary: #409eff;
  --primary-dark: #337ecc;
  --shadow: 0 2px 12px rgba(0,0,0,0.08);
  --radius: 10px;
}

[data-theme="dark"] {
  --bg: #1a1a2e;
  --bg2: #16213e;
  --bg3: #0f3460;
  --border: #2d3561;
  --text: #e0e0e0;
  --text2: #a0a0b0;
  --text3: #6c6c8a;
  --primary: #5b86e5;
  --primary-dark: #3a5abf;
  --shadow: 0 2px 12px rgba(0,0,0,0.3);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  transition: background 0.3s, color 0.3s;
  font-size: 15px;
}

/* ===== Header ===== */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg2);
  border-bottom: 1px solid var(--border);
  box-shadow: var(--shadow);
  padding: 0 24px;
  height: 60px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.header-left { flex: 0 0 auto; }
.logo { font-size: 20px; font-weight: 700; color: var(--primary); }

.header-center { flex: 1; max-width: 600px; margin: 0 auto; }

.search-box {
  display: flex;
  align-items: center;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 24px;
  overflow: hidden;
  transition: box-shadow 0.2s;
}
.search-box:focus-within { box-shadow: 0 0 0 2px var(--primary); border-color: var(--primary); }

.search-box select {
  border: none;
  background: transparent;
  color: var(--text2);
  padding: 0 8px 0 14px;
  font-size: 15px;
  outline: none;
  cursor: pointer;
}

.search-box input {
  flex: 1;
  border: none;
  background: transparent;
  color: var(--text);
  padding: 10px 8px;
  font-size: 15px;
  outline: none;
}

.search-box button {
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 0 20px;
  height: 42px;
  font-size: 15px;
  cursor: pointer;
  transition: background 0.2s;
}
.search-box button:hover { background: var(--primary-dark); }

.header-right { flex: 0 0 auto; display: flex; align-items: center; gap: 12px; }

.weather-widget {
  display: flex;
  align-items: center;
  gap: 5px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 5px 14px;
  font-size: 15px;
  color: var(--text2);
  white-space: nowrap;
}

.weather-widget #weatherIcon { font-size: 16px; }

.theme-btn {
  border: none;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 50%;
  width: 36px;
  height: 36px;
  font-size: 16px;
  cursor: pointer;
  transition: transform 0.3s;
}
.theme-btn:hover { transform: rotate(20deg); }

/* ===== Main ===== */
.main {
  max-width: 1280px;
  margin: 0 auto;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.section {
  background: var(--bg2);
  border-radius: var(--radius);
  padding: 20px 24px;
  box-shadow: var(--shadow);
}

.section-title {
  font-size: 18px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--border);
}

/* ===== Nav Tabs ===== */
.nav-tabs, .tools-tabs {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.nav-tab, .tool-tab {
  border: 1px solid var(--border);
  background: var(--bg3);
  color: var(--text2);
  padding: 6px 18px;
  border-radius: 20px;
  font-size: 15px;
  cursor: pointer;
  transition: all 0.2s;
}

.nav-tab:hover, .tool-tab:hover {
  border-color: var(--primary);
  color: var(--primary);
}

.nav-tab.active, .tool-tab.active {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

/* ===== Nav Grid ===== */
.nav-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 12px;
}

.nav-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 16px 8px;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  text-decoration: none;
  color: var(--text);
  font-size: 15px;
  text-align: center;
  transition: all 0.2s;
  cursor: pointer;
}

.nav-card:hover {
  border-color: var(--primary);
  box-shadow: 0 4px 16px rgba(64,158,255,0.15);
  transform: translateY(-2px);
  color: var(--primary);
}

.nav-card .icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  background: var(--bg2);
}

.nav-card .name { font-weight: 500; }
.nav-card .desc { font-size: 13px; color: var(--text3); line-height: 1.3; }

/* ===== Tool Panel ===== */
.tool-panel {
  min-height: 200px;
}

.tool-content { display: flex; flex-direction: column; gap: 12px; }

.tool-row { display: flex; gap: 12px; flex-wrap: wrap; align-items: flex-start; }

.tool-label {
  font-size: 13px;
  color: var(--text2);
  margin-bottom: 4px;
  font-weight: 500;
}

.tool-textarea, .tool-input, .tool-select {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  padding: 10px 12px;
  font-size: 15px;
  font-family: inherit;
  outline: none;
  resize: vertical;
  transition: border-color 0.2s;
}

.tool-textarea:focus, .tool-input:focus, .tool-select:focus {
  border-color: var(--primary);
}

.tool-textarea { min-height: 120px; }

.tool-btn {
  border: none;
  background: var(--primary);
  color: #fff;
  padding: 8px 20px;
  border-radius: 8px;
  font-size: 15px;
  cursor: pointer;
  white-space: nowrap;
  transition: background 0.2s;
}
.tool-btn:hover { background: var(--primary-dark); }
.tool-btn.secondary {
  background: var(--bg3);
  color: var(--text2);
  border: 1px solid var(--border);
}
.tool-btn.secondary:hover { border-color: var(--primary); color: var(--primary); background: var(--bg3); }

.tool-result {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 12px;
  font-size: 13px;
  color: var(--text);
  min-height: 80px;
  word-break: break-all;
  white-space: pre-wrap;
  font-family: 'Courier New', monospace;
}

.tool-stats {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

.stat-item {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 10px 16px;
  text-align: center;
  min-width: 90px;
}

.stat-value { font-size: 22px; font-weight: 700; color: var(--primary); }
.stat-label { font-size: 11px; color: var(--text3); margin-top: 2px; }

/* color tool */
.color-preview {
  width: 100%;
  height: 60px;
  border-radius: 8px;
  border: 1px solid var(--border);
  transition: background 0.3s;
}

.color-formats { display: flex; flex-direction: column; gap: 6px; }
.color-format-row {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
}
.color-format-row label { width: 50px; color: var(--text3); }
.color-format-row span {
  flex: 1;
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 4px 10px;
  font-family: monospace;
  cursor: pointer;
}
.color-format-row span:hover { border-color: var(--primary); color: var(--primary); }

/* ===== Footer ===== */
.footer {
  text-align: center;
  padding: 16px;
  font-size: 12px;
  color: var(--text3);
  border-top: 1px solid var(--border);
  background: var(--bg2);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .header { padding: 0 12px; gap: 8px; }
  .header-center { max-width: 100%; }
  .weather-widget { display: none; }
  .main { padding: 12px; }
  .section { padding: 14px; }
  .nav-grid { grid-template-columns: repeat(auto-fill, minmax(100px, 1fr)); gap: 8px; }
}

/* ===== 时间日期工具 ===== */
.time-now-block {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
  border-radius: var(--radius);
  padding: 20px 24px;
  text-align: center;
  color: #fff;
  margin-bottom: 4px;
}
.time-now-clock {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: 4px;
  font-variant-numeric: tabular-nums;
  line-height: 1.1;
}
.time-now-date {
  font-size: 15px;
  opacity: 0.9;
  margin: 6px 0 12px;
}
.time-now-stamps {
  display: flex;
  justify-content: center;
  gap: 24px;
  flex-wrap: wrap;
  font-size: 13px;
  opacity: 0.92;
}
.time-now-stamps b { margin: 0 4px; font-variant-numeric: tabular-nums; }

.time-card {
  background: var(--bg3);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.time-card-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--primary);
  border-left: 3px solid var(--primary);
  padding-left: 8px;
}

.time-result-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 8px;
}
.time-result-item {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg2);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  font-size: 13px;
}
.trl {
  color: var(--text3);
  white-space: nowrap;
  min-width: 80px;
}
.trv {
  flex: 1;
  color: var(--text);
  font-weight: 500;
  font-variant-numeric: tabular-nums;
  word-break: break-all;
}

.tool-btn-xs {
  border: 1px solid var(--border);
  background: var(--bg3);
  color: var(--text3);
  padding: 2px 8px;
  border-radius: 6px;
  font-size: 11px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s;
}
.tool-btn-xs:hover { border-color: var(--primary); color: var(--primary); }