/* ===== 工具站 CSS - 暗黑主题 ===== */
:root {
  --bg: #0d1117;
  --bg-card: #161b22;
  --bg-hover: #1c2333;
  --border: #30363d;
  --text: #c9d1d9;
  --text-dim: #8b949e;
  --accent: #58a6ff;
  --accent2: #3fb950;
  --accent3: #f0883e;
  --danger: #f85149;
  --ad-bg: #1a1f2b;
  --ad-border: #ffd70044;
  --shadow: 0 4px 24px rgba(0,0,0,0.4);
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
}

/* ===== HEADER ===== */
.header {
  background: var(--bg-card);
  border-bottom: 1px solid var(--border);
  padding: 0 20px;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(12px);
}

.logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-decoration: none;
  white-space: nowrap;
}

.nav-links { display: flex; gap: 24px; list-style: none; align-items: center; }
.nav-links a {
  color: var(--text-dim);
  text-decoration: none;
  font-size: 0.9rem;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--text); }
.nav-links .premium-btn {
  background: linear-gradient(135deg, var(--accent3), #f0883ecc);
  color: #fff;
  padding: 8px 18px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 0.85rem;
}

/* ===== HERO ===== */
.hero {
  text-align: center;
  padding: 60px 20px 40px;
  background: linear-gradient(180deg, var(--bg-card) 0%, var(--bg) 100%);
}
.hero h1 { font-size: 2.5rem; margin-bottom: 12px; }
.hero h1 span { color: var(--accent); }
.hero p { color: var(--text-dim); font-size: 1.1rem; max-width: 600px; margin: 0 auto 24px; }

.search-box {
  display: flex;
  max-width: 560px;
  margin: 0 auto;
  position: relative;
}
.search-box input {
  flex: 1;
  padding: 14px 20px;
  border: 2px solid var(--border);
  border-radius: 12px;
  background: var(--bg-card);
  color: var(--text);
  font-size: 1rem;
  outline: none;
  transition: border-color 0.2s;
}
.search-box input:focus { border-color: var(--accent); }
.search-box button {
  position: absolute;
  right: 4px;
  top: 4px;
  padding: 10px 24px;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-weight: 600;
  cursor: pointer;
}

/* ===== AD SPACE ===== */
.ad-space {
  background: var(--ad-bg);
  border: 2px dashed var(--ad-border);
  border-radius: 12px;
  text-align: center;
  padding: 16px;
  margin: 16px auto;
  max-width: 728px;
}
.ad-space.wide { max-width: 970px; }
.ad-space.sidebar { max-width: 300px; }
.ad-space .ad-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--text-dim);
  margin-bottom: 8px;
}
.ad-space .ad-content {
  min-height: 90px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-dim);
  font-size: 0.85rem;
  background: var(--bg);
  border-radius: 8px;
}
.ad-space.sidebar .ad-content { min-height: 250px; }

/* ===== STATS BAR ===== */
.stats-bar {
  display: flex;
  justify-content: center;
  gap: 48px;
  padding: 32px 20px;
  flex-wrap: wrap;
}
.stat-item { text-align: center; }
.stat-num { font-size: 2rem; font-weight: 700; color: var(--accent); }
.stat-label { font-size: 0.85rem; color: var(--text-dim); margin-top: 4px; }

/* ===== CATEGORIES ===== */
.categories {
  display: flex;
  justify-content: center;
  gap: 8px;
  flex-wrap: wrap;
  padding: 0 20px 16px;
}
.cat-btn {
  padding: 8px 18px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s;
}
.cat-btn:hover, .cat-btn.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ===== TOOLS GRID ===== */
.container { max-width: 1200px; margin: 0 auto; padding: 0 20px; }
.section-title {
  font-size: 1.5rem;
  margin: 40px 0 20px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border);
}

.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 16px;
  margin-bottom: 40px;
}

.tool-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px 20px;
  cursor: pointer;
  transition: all 0.2s;
  text-decoration: none;
  color: inherit;
  display: block;
  position: relative;
  overflow: hidden;
}
.tool-card:hover {
  background: var(--bg-hover);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: var(--shadow);
}
.tool-card .tool-icon {
  font-size: 2rem;
  margin-bottom: 12px;
  display: block;
}
.tool-card .tool-name { font-weight: 600; font-size: 1rem; margin-bottom: 6px; }
.tool-card .tool-desc { color: var(--text-dim); font-size: 0.85rem; line-height: 1.4; }
.tool-card .tool-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  background: var(--accent2);
  color: #000;
  font-size: 0.65rem;
  padding: 2px 8px;
  border-radius: 10px;
  font-weight: 700;
}

/* ===== AD INLINE ===== */
.ad-inline {
  background: var(--ad-bg);
  border: 2px dashed var(--ad-border);
  border-radius: 12px;
  text-align: center;
  padding: 20px;
  margin: 24px 0;
}
.ad-inline .ad-label { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 2px; color: var(--text-dim); }
.ad-inline .ad-content { min-height: 90px; display: flex; align-items: center; justify-content: center; color: var(--text-dim); background: var(--bg); border-radius: 8px; margin-top: 8px; }

/* ===== TOOL MODAL / PAGE ===== */
.tool-page {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
}
.tool-page h1 { font-size: 2rem; margin-bottom: 8px; }
.tool-page .breadcrumb { color: var(--text-dim); font-size: 0.85rem; margin-bottom: 24px; }
.tool-page .breadcrumb a { color: var(--accent); text-decoration: none; }

/* Tab buttons (crypto tools: text/file switch) */
.tab-btn {
  padding: 8px 18px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  font-size: 0.9rem;
  transition: all 0.2s;
}
.tab-btn.active { background: var(--accent); color: #fff; border-color: var(--accent); }
.tab-btn:hover:not(.active) { border-color: var(--accent); color: var(--text); }

.tool-workspace {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 32px;
  margin: 24px 0;
}

.tool-workspace textarea {
  width: 100%;
  min-height: 200px;
  padding: 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.9rem;
  resize: vertical;
}
.tool-workspace textarea:focus { outline: none; border-color: var(--accent); }

.tool-workspace input[type="text"],
.tool-workspace input[type="number"],
.tool-workspace input[type="url"],
.tool-workspace select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: 8px;
  background: var(--bg);
  color: var(--text);
  font-size: 0.95rem;
}
.tool-workspace input:focus, .tool-workspace select:focus { outline: none; border-color: var(--accent); }

.tool-workspace button {
  padding: 12px 32px;
  background: var(--accent);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: opacity 0.2s;
}
.tool-workspace button:hover { opacity: 0.9; }
.tool-workspace button.secondary {
  background: var(--border);
  color: var(--text);
}

.btn-row { display: flex; gap: 12px; margin: 16px 0; flex-wrap: wrap; align-items: center; }

.result-box {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 16px;
  margin-top: 16px;
  min-height: 60px;
  font-family: 'SF Mono', 'Fira Code', monospace;
  font-size: 0.9rem;
  white-space: pre-wrap;
  word-break: break-all;
}
.result-box:empty::before { content: '结果将显示在这里...'; color: var(--text-dim); }
.result-box.json { max-height: 400px; overflow-y: auto; }

/* ===== FOOTER ===== */
.footer {
  background: var(--bg-card);
  border-top: 1px solid var(--border);
  padding: 48px 20px 24px;
  margin-top: 48px;
}
.footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 32px;
}
.footer-col h4 { margin-bottom: 16px; font-size: 0.9rem; color: var(--text-dim); text-transform: uppercase; letter-spacing: 1px; }
.footer-col a { display: block; color: var(--text); text-decoration: none; font-size: 0.9rem; margin-bottom: 8px; }
.footer-col a:hover { color: var(--accent); }
.footer-bottom {
  max-width: 1200px;
  margin: 32px auto 0;
  padding-top: 24px;
  border-top: 1px solid var(--border);
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
  font-size: 0.85rem;
  color: var(--text-dim);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
  .hero h1 { font-size: 1.8rem; }
  .tools-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); }
  .stats-bar { gap: 24px; }
  .tool-workspace { padding: 20px; }
  .header { padding: 0 12px; }
  .nav-links { gap: 12px; }
}

/* Ad space responsiveness */
@media (max-width: 768px) {
  .ad-space, .ad-space.wide { max-width: 100%; }
  .ad-space .ad-content { min-height: 50px; }
}

/* Hide class for filtering */
.tool-card.hidden { display: none; }

/* Coming soon overlay */
.tool-card.coming-soon { opacity: 0.7; }
.tool-card.coming-soon::after {
  content: "COMING SOON";
  position: absolute;
  top: 8px;
  right: 8px;
  background: var(--text-dim);
  color: var(--bg);
  font-size: 0.6rem;
  padding: 3px 8px;
  border-radius: 4px;
  font-weight: 700;
}

/* Error state */
.error-box { background: #f8514922; border: 1px solid var(--danger); border-radius: 8px; padding: 16px; color: var(--danger); margin-top: 16px; }

/* Success */
.success-box { background: #3fb95022; border: 1px solid var(--accent2); border-radius: 8px; padding: 16px; color: var(--accent2); margin-top: 16px; }

/* Copy button */
.copy-btn {
  padding: 8px 16px;
  background: var(--border);
  border: 1px solid var(--border);
  border-radius: 6px;
  color: var(--text);
  cursor: pointer;
  font-size: 0.85rem;
}
.copy-btn:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* Tabs inside tool pages */
.tool-tabs { display: flex; gap: 4px; margin-bottom: 20px; }
.tool-tab {
  padding: 8px 20px;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  border-radius: 8px 8px 0 0;
  font-size: 0.9rem;
}
.tool-tab.active { background: var(--accent); color: #fff; border-color: var(--accent); }

/* Conversion row */
.convert-row { display: flex; gap: 16px; align-items: center; flex-wrap: wrap; }
.convert-row .arrow { font-size: 1.5rem; color: var(--accent); }

/* BMI result */
.bmi-result { text-align: center; padding: 24px; }
.bmi-result .bmi-num { font-size: 3rem; font-weight: 700; }
.bmi-result .bmi-label { color: var(--text-dim); margin-top: 8px; }

/* 2-col layout */
.row-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
@media (max-width: 600px) { .row-2col { grid-template-columns: 1fr; } }

/* QR code */
.qr-output { text-align: center; padding: 24px; }
.qr-output canvas { border: 8px solid #fff; border-radius: 8px; }

/* JSON formatter */
.json-key { color: #79c0ff; }
.json-string { color: #a5d6ff; }
.json-number { color: #79c0ff; }
.json-boolean { color: #ff7b72; }

/* Color swatch */
.color-swatch { width: 60px; height: 60px; border-radius: 8px; border: 2px solid var(--border); display: inline-block; margin-right: 16px; vertical-align: middle; }

/* Loading spinner */
.spinner {
  display: inline-block;
  width: 20px; height: 20px;
  border: 2px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--accent2);
  color: #000;
  padding: 12px 24px;
  border-radius: 8px;
  font-weight: 600;
  z-index: 999;
  animation: fadeIn 0.3s;
}
@keyframes fadeIn { from { opacity: 0; transform: translateY(16px); } to { opacity: 1; transform: translateY(0); } }

/* Upload Zone */
.upload-zone {
  border: 2px dashed var(--border);
  border-radius: 16px;
  padding: 40px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
  background: var(--bg);
}
.upload-zone:hover, .upload-zone.dragover {
  border-color: var(--accent);
  background: var(--bg-hover);
}

.upload-area {
  border: 2px dashed var(--accent);
  border-radius: 16px;
  padding: 48px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.3s;
  background: color-mix(in srgb, var(--accent) 6%, var(--bg));
  position: relative;
  overflow: hidden;
}
.upload-area::before {
  content: '';
  position: absolute;
  inset: 8px;
  border: 1px dashed color-mix(in srgb, var(--accent) 25%, transparent);
  border-radius: 12px;
  pointer-events: none;
}
.upload-area:hover {
  border-color: var(--accent-hover, #58a6ff);
  background: color-mix(in srgb, var(--accent) 12%, var(--bg));
  transform: translateY(-1px);
  box-shadow: 0 4px 16px color-mix(in srgb, var(--accent) 20%, transparent);
}
.upload-area.dragover {
  border-style: solid;
  border-color: var(--accent2, #3fb950);
  background: color-mix(in srgb, var(--accent2) 15%, var(--bg));
  transform: scale(1.02);
  box-shadow: 0 0 0 4px color-mix(in srgb, var(--accent2) 20%, transparent);
}
.upload-area p {
  color: var(--text-dim);
  margin-top: 8px;
  font-size: 0.95rem;
}
.upload-area:hover p {
  color: var(--accent);
}

/* Dark/Light mode */
body.light {
  --bg: #ffffff;
  --bg-card: #f6f8fa;
  --bg-hover: #eef1f5;
  --border: #d0d7de;
  --text: #1f2328;
  --text-dim: #656d76;
  --ad-bg: #f0f2f5;
  --ad-border: #f0883e44;
  --shadow: 0 4px 24px rgba(0,0,0,0.08);
}

body.light .hero { background: linear-gradient(180deg, var(--bg-card) 0%, var(--bg) 100%); }
body.light .tool-card.coming-soon::after { color: #fff; }

/* Theme toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  font-size: 1.2rem;
  color: var(--text);
  transition: all 0.2s;
}
.theme-toggle:hover { border-color: var(--accent); }

/* Stats counter animation */
.stat-num { counter-reset: none; }

/* Tooltip */
[data-tooltip] { position: relative; }
[data-tooltip]:hover::after {
  content: attr(data-tooltip);
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 0.8rem;
  white-space: nowrap;
  z-index: 10;
  pointer-events: none;
  margin-top: 4px;
}