:root {
  --bg: #f6f7fb;
  --surface: #ffffff;
  --text: #1f2330;
  --muted: #6b7280;
  --border: #e5e7ef;
  --primary: #4f6df5;
  --primary-hover: #3a55d8;
  --shadow: 0 6px 20px rgba(31, 35, 48, 0.06);
  --radius: 12px;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Helvetica Neue",
    Helvetica, "Segoe UI", Arial, "Microsoft YaHei", sans-serif;
  -webkit-font-smoothing: antialiased;
}

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

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 32px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
}

.site-header .brand {
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.5px;
}

.site-header .brand a { color: var(--text); }

.site-header nav a {
  margin-left: 20px;
  color: var(--muted);
  font-size: 14px;
}

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 48px 24px;
}

.page-title {
  margin: 0 0 8px;
  font-size: 28px;
  font-weight: 700;
}

.page-subtitle {
  margin: 0 0 32px;
  color: var(--muted);
  font-size: 15px;
}

.tool-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 20px;
}

.tool-card {
  display: block;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
  color: var(--text);
}

.tool-card:hover {
  transform: translateY(-2px);
  border-color: var(--primary);
  box-shadow: 0 10px 24px rgba(79, 109, 245, 0.12);
  color: var(--text);
}

.tool-card .icon {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: linear-gradient(135deg, #6e8bff, #4f6df5);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 18px;
  margin-bottom: 14px;
}

.tool-card .title {
  font-size: 16px;
  font-weight: 600;
  margin: 0 0 6px;
}

.tool-card .desc {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.6;
  margin: 0;
}

.tool-card.disabled {
  opacity: 0.55;
  pointer-events: none;
}

.site-footer {
  text-align: center;
  padding: 24px;
  color: var(--muted);
  font-size: 12px;
}

button {
  font-family: inherit;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 13px;
  cursor: pointer;
  transition: background 0.15s ease, border-color 0.15s ease, color 0.15s ease;
}

.btn:hover { border-color: var(--primary); color: var(--primary); }

.btn.primary {
  background: var(--primary);
  border-color: var(--primary);
  color: #fff;
}

.btn.primary:hover {
  background: var(--primary-hover);
  border-color: var(--primary-hover);
  color: #fff;
}