/* ================================
   颜色转换工具 - 自定义样式
   ================================ */

:root {
  --bg: #FAFAF9;
  --bg-alt: #F5F5F4;
  --surface: #FFFFFF;
  --border: #E7E5E4;
  --border-strong: #D6D3D1;
  --text: #1E293B;
  --text-secondary: #52525B;
  --text-muted: #71717A;
  --primary: #4F46E5;
  --primary-hover: #4338CA;
  --primary-light: rgba(79, 70, 229, 0.08);
  --secondary: #F97316;
  --accent: #EC4899;
  --success: #059669;
  --radius: 10px;
  --radius-lg: 14px;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
  --shadow: 0 4px 12px rgba(0, 0, 0, 0.06);
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', 'Noto Sans SC', system-ui, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

/* ── Toast ── */
.toast {
  position: fixed; top: 24px; right: 24px;
  background: var(--text); color: var(--bg);
  padding: 10px 18px; border-radius: 100px;
  font-size: 14px; font-weight: 500;
  display: flex; align-items: center; gap: 8px;
  z-index: 1000;
  transform: translateX(calc(100% + 40px));
  transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}
.toast.show { transform: translateX(0); }
.toast-dot { width: 8px; height: 8px; background: var(--success); border-radius: 50%; }

/* ── Page ── */
.page { max-width: 960px; margin: 0 auto; padding: 0 32px; }

::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: #f1f5f9; }
::-webkit-scrollbar-thumb { background: #A5B4FC; border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: #4F46E5; }

::selection { background: rgba(79, 70, 229, 0.2); color: #1E293B; }

/* ══════════════════════════════════════════
   Tool Section
   ══════════════════════════════════════════ */
.tool-section { padding: 24px 0; }

/* ── Color Preview ── */
.color-preview {
  width: 100%; height: 120px;
  border-radius: var(--radius-lg);
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--shadow-lg);
  transition: background-color 0.3s ease;
  margin-bottom: 20px;
  background-color: #4F46E5;
}
.color-preview-text {
  font-family: 'SF Mono', 'Cascadia Code', 'Fira Code', monospace;
  font-size: 24px; font-weight: 700;
  color: white;
  text-shadow: 0 2px 8px rgba(0,0,0,0.3);
  user-select: text;
}

/* ── Picker ── */
.picker-row {
  display: flex; align-items: center; gap: 10px;
  margin-bottom: 16px;
}
.color-picker-input {
  width: 40px; height: 40px;
  border: 1px solid var(--border);
  border-radius: 8px;
  cursor: pointer;
  padding: 0;
}
.color-picker-input::-webkit-color-swatch-wrapper { padding: 0; }
.color-picker-input::-webkit-color-swatch { border: none; border-radius: 6px; }
.picker-label {
  font-size: 13px; color: var(--text-muted);
}

/* ── Presets ── */
.presets-row {
  display: flex; align-items: center; gap: 8px;
  margin-bottom: 20px;
  flex-wrap: wrap;
}
.presets-label {
  font-size: 13px; color: var(--text-muted);
  margin-right: 4px;
}
.preset-dot {
  width: 28px; height: 28px;
  border-radius: 50%;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
  box-shadow: 0 1px 3px rgba(0,0,0,0.1);
}
.preset-dot:hover { transform: scale(1.2); box-shadow: 0 2px 8px rgba(0,0,0,0.2); }

/* ── Section Label ── */
.section-label {
  font-size: 13px; font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

/* ── Input ── */
.input-row {
  display: flex; gap: 8px;
  margin-bottom: 20px;
}
.input-field {
  flex: 1; padding: 12px 14px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  font-family: inherit; font-size: 15px; color: var(--text);
  outline: none;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}
.input-field:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}
.input-field--mono { font-family: 'SF Mono', 'Cascadia Code', 'Fira Code', monospace; font-size: 14px; }

.btn-secondary {
  padding: 10px 22px;
  background: var(--bg-alt);
  border: 1px solid var(--border);
  border-radius: 100px;
  font-family: inherit; font-size: 14px; font-weight: 500;
  color: var(--text-secondary); cursor: pointer;
  transition: all 0.15s ease;
}
.btn-secondary:hover { background: var(--border); color: var(--text); }

/* ── Format Grid ── */
.format-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: 12px;
  margin-top: 8px;
}
.format-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 16px;
  transition: all 0.2s ease;
}
.format-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow);
}
.format-card-label {
  display: block; font-size: 11px; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.08em;
  color: var(--text-muted); margin-bottom: 8px;
}
.format-card-value {
  display: block;
  font-family: 'SF Mono', 'Cascadia Code', 'Fira Code', monospace;
  font-size: 14px; font-weight: 600;
  color: var(--text);
  margin-bottom: 10px;
  word-break: break-all;
}
.btn-copy-sm {
  padding: 5px 14px;
  background: transparent; border: 1px solid var(--border);
  border-radius: 100px;
  font-family: inherit; font-size: 12px; font-weight: 500;
  color: var(--text-muted); cursor: pointer;
  transition: all 0.15s ease;
}
.btn-copy-sm:hover {
  background: var(--primary-light);
  border-color: rgba(79,70,229,0.25);
  color: var(--primary);
}

/* ══════════════════════════════════════════
   Guide Section
   ══════════════════════════════════════════ */
.guide-section {
  margin-top: 16px;
  margin-bottom: 64px;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}
.guide-toggle {
  display: flex; align-items: center; justify-content: space-between;
  width: 100%; padding: 14px 20px;
  background: none; border: none; cursor: pointer;
  transition: background 0.15s ease;
}
.guide-toggle:hover { background: var(--bg-alt); }
.guide-toggle-title {
  display: flex; align-items: center; gap: 8px;
  font-size: 14px; font-weight: 600; color: #1E293B;
}
.guide-toggle.open .toggle-arrow { transform: rotate(180deg); }
.toggle-arrow {
  transition: transform 0.2s ease; color: var(--text-muted);
}
.guide-list { padding: 0 20px 20px; }
.guide-list.hidden { display: none; }
.guide-item {
  padding: 16px 0; border-top: 1px solid var(--border);
}
.guide-item-title {
  font-size: 14px; font-weight: 600; color: #1E293B; margin-bottom: 6px;
}
.guide-item-body {
  font-size: 13px; color: var(--text-secondary); line-height: 1.8;
}

/* ══════════════════════════════════════════
   Responsive
   ══════════════════════════════════════════ */
@media (max-width: 768px) {
  .page { padding: 0 16px; }
  .color-preview { height: 100px; }
  .color-preview-text { font-size: 18px; }
  .format-grid { grid-template-columns: 1fr 1fr; }
  .input-row { flex-wrap: wrap; }
  .input-field { min-width: 100%; }
}