/* === AI小店 全局样式 === */
:root {
  --primary: #6366f1;
  --primary-dark: #4f46e5;
  --primary-light: #eef2ff;
  --accent: #06b6d4;
  --accent-light: #ecfeff;
  --success: #10b981;
  --success-light: #ecfdf5;
  --warning: #f59e0b;
  --gray-50: #f9fafb;
  --gray-100: #f3f4f6;
  --gray-200: #e5e7eb;
  --gray-300: #d1d5db;
  --gray-400: #9ca3af;
  --gray-500: #6b7280;
  --gray-600: #4b5563;
  --gray-700: #374151;
  --gray-800: #1f2937;
  --gray-900: #111827;
  --radius: 12px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 6px rgba(0,0,0,0.07), 0 2px 4px rgba(0,0,0,0.06);
  --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  color: var(--gray-800);
  background: var(--gray-50);
  line-height: 1.6;
  min-height: 100vh;
}

a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-dark); }

/* === Header === */
header {
  background: #fff;
  border-bottom: 1px solid var(--gray-200);
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(8px);
}
header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  max-width: 1200px;
  margin: 0 auto;
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--gray-900);
}
.logo-icon {
  width: 36px; height: 36px;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 18px;
}
nav { display: flex; align-items: center; gap: 20px; }
nav a {
  font-size: 14px;
  color: var(--gray-600);
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 6px;
  transition: all 0.2s;
}
nav a:hover { background: var(--gray-100); color: var(--gray-900); }

/* === Hero === */
.hero {
  text-align: center;
  padding: 60px 24px 48px;
  background: linear-gradient(135deg, #eef2ff 0%, #ecfeff 50%, #fdf2f8 100%);
}
.hero h1 {
  font-size: 42px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--primary), var(--accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}
.hero p {
  font-size: 18px;
  color: var(--gray-500);
  max-width: 600px;
  margin: 0 auto 24px;
}
.hero .badge {
  display: inline-block;
  background: var(--success-light);
  color: var(--success);
  font-size: 13px;
  font-weight: 600;
  padding: 4px 14px;
  border-radius: 20px;
  margin-bottom: 16px;
}

/* === Tools Grid === */
.tools-section {
  max-width: 1200px;
  margin: 0 auto;
  padding: 48px 24px;
}
.tools-section h2 {
  font-size: 28px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
}
.tools-section .subtitle {
  text-align: center;
  color: var(--gray-500);
  margin-bottom: 32px;
  font-size: 15px;
}
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.tool-card {
  background: #fff;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
  transition: all 0.25s;
  cursor: pointer;
}
.tool-card:hover {
  border-color: var(--primary);
  box-shadow: var(--shadow-lg);
  transform: translateY(-2px);
}
.tool-card .icon {
  width: 56px; height: 56px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto 16px;
  font-size: 26px;
}
.tool-card h3 { font-size: 17px; font-weight: 600; margin-bottom: 6px; }
.tool-card p { font-size: 13px; color: var(--gray-500); margin-bottom: 16px; line-height: 1.5; }
.tool-card .tag {
  display: inline-block;
  font-size: 11px; font-weight: 600;
  padding: 2px 10px;
  border-radius: 10px;
  background: var(--primary-light);
  color: var(--primary);
}
.tool-card .tag.free { background: var(--success-light); color: var(--success); }

/* === Tool Page (通用) === */
.tool-page {
  max-width: 800px;
  margin: 0 auto;
  padding: 32px 24px 64px;
}
.tool-page .back {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  color: var(--gray-500);
  margin-bottom: 24px;
  transition: color 0.2s;
}
.tool-page .back:hover { color: var(--primary); }
.tool-page h1 { font-size: 28px; font-weight: 700; margin-bottom: 6px; }
.tool-page .desc { color: var(--gray-500); margin-bottom: 28px; font-size: 15px; }

.form-group {
  margin-bottom: 20px;
}
.form-group label {
  display: block;
  font-size: 14px;
  font-weight: 600;
  color: var(--gray-700);
  margin-bottom: 6px;
}
.form-group textarea,
.form-group input[type="text"] {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--gray-300);
  border-radius: 8px;
  font-size: 14px;
  font-family: inherit;
  transition: border 0.2s;
  background: #fff;
}
.form-group textarea:focus,
.form-group input:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(99,102,241,0.1);
}
.form-group textarea { min-height: 140px; resize: vertical; }

.upload-zone {
  border: 2px dashed var(--gray-300);
  border-radius: var(--radius);
  padding: 40px 20px;
  text-align: center;
  cursor: pointer;
  transition: all 0.2s;
  background: var(--gray-50);
}
.upload-zone:hover { border-color: var(--primary); background: var(--primary-light); }
.upload-zone .icon { font-size: 36px; margin-bottom: 8px; }
.upload-zone p { font-size: 14px; color: var(--gray-500); }
.upload-zone .hint { font-size: 12px; color: var(--gray-400); margin-top: 4px; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 15px;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
}
.btn-primary {
  background: linear-gradient(135deg, var(--primary), var(--primary-dark));
  color: #fff;
}
.btn-primary:hover { box-shadow: var(--shadow-md); transform: translateY(-1px); }
.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }
.btn-outline {
  background: #fff;
  color: var(--gray-700);
  border: 1px solid var(--gray-300);
}
.btn-outline:hover { background: var(--gray-50); }

.result-box {
  margin-top: 28px;
  padding: 20px;
  border: 1px solid var(--gray-200);
  border-radius: var(--radius);
  background: #fff;
  display: none;
}
.result-box.visible { display: block; }
.result-box .label {
  font-size: 12px;
  font-weight: 600;
  color: var(--gray-400);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 8px;
}
.result-box .content {
  font-size: 14px;
  line-height: 1.7;
  white-space: pre-wrap;
  color: var(--gray-700);
}
.result-box .actions {
  margin-top: 16px;
  display: flex;
  gap: 10px;
}

.loading {
  display: none;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 20px;
  color: var(--gray-500);
}
.loading.visible { display: flex; }
.spinner {
  width: 20px; height: 20px;
  border: 2px solid var(--gray-200);
  border-top: 2px solid var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

/* === Footer === */
footer {
  background: #fff;
  border-top: 1px solid var(--gray-200);
  padding: 24px;
  text-align: center;
  font-size: 13px;
  color: var(--gray-500);
}
footer a { color: var(--gray-500); }
footer a:hover { color: var(--gray-700); }

/* === Usage Counter === */
.usage-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--gray-100);
  border-radius: 8px;
  padding: 10px 16px;
  margin-bottom: 20px;
  font-size: 13px;
}
.usage-bar .count {
  font-weight: 600;
  color: var(--primary);
}
.usage-bar .free-text { color: var(--gray-500); }

/* === Responsive === */
@media (max-width: 640px) {
  .hero h1 { font-size: 28px; }
  .tools-grid { grid-template-columns: 1fr; }
  nav a { font-size: 12px; padding: 4px 8px; }
  header .container { padding: 10px 16px; }
}

/* === AI Content Watermark === */
.ai-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 11px;
  color: var(--gray-400);
  padding: 2px 8px;
  border: 1px solid var(--gray-200);
  border-radius: 4px;
}