:root {
  --color-primary: #111827;
  --color-primary-hover: #1f2937;
  --color-text: #1f2937;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-background: #fff;
  --color-surface: #f8fafc;
  --color-surface-alt: #f1f5f9;
  --color-border: #e5e7eb;
  --color-border-strong: #d1d5db;
  --color-success: #16a34a;
  --color-warning: #b45309;
  --color-error: #dc2626;
  --color-error-strong: #b91c1c;
  --color-info: #2563eb;
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 10px;
  --radius-xl: 14px;
  --radius-full: 999px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; font-family: Arial, sans-serif; color: var(--color-text); background: var(--color-background); }
a { color: inherit; text-decoration: none; }
a:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; border-radius: var(--radius-sm); }
.container { width: min(1120px, calc(100% - 32px)); margin: 0 auto; }

.site-header { border-bottom: 1px solid var(--color-border); background: var(--color-background); }
.header-inner { min-height: 64px; display: flex; align-items: center; justify-content: space-between; }
.logo { display: inline-flex; align-items: center; gap: 8px; font-size: 22px; font-weight: 800; letter-spacing: -0.01em; color: var(--color-primary); text-decoration: none; }
.logo-mark { width: 28px; height: 28px; flex-shrink: 0; }
.main-nav { display: flex; gap: 28px; font-size: 14px; }
.main-nav a { padding: 4px 0; color: var(--color-text-secondary); font-weight: 500; }
.main-nav a:hover { color: var(--color-primary); text-decoration: underline; }
.main-nav a.is-active { color: var(--color-primary); font-weight: 700; }
.main-nav a:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 4px; border-radius: var(--radius-sm); }
.menu-button { display: none; border: 0; background: transparent; font-size: 24px; cursor: pointer; border-radius: var(--radius-sm); }
.menu-button:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }

.hero { padding: 80px 0; text-align: center; background: var(--color-surface); }
.hero h1 { margin: 0 0 16px; font-size: 48px; }
.hero p { margin: 0 auto 32px; max-width: 600px; color: var(--color-text-secondary); font-size: 18px; }
.tool-search { max-width: 600px; margin: 0 auto; }
.tool-search input { width: 100%; padding: 16px 20px; border: 1px solid var(--color-border-strong); border-radius: var(--radius-lg); font-size: 16px; outline: none; }
.tool-search input:focus { border-color: var(--color-primary); }

.tools-section { padding: 64px 0; }
.tools-section h2 { margin: 0 0 32px; font-size: 30px; }
/* Category pages already have a breadcrumb + H1 + description above this section,
   so it doesn't need the homepage's hero-to-grid breathing room. */
.tool-page .tools-section { padding: 8px 0 56px; }
.tools-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.tool-card { display: flex; flex-direction: column; padding: 24px; border: 1px solid var(--color-border); border-radius: var(--radius-xl); transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease; }
.tool-card:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(0,0,0,.08); border-color: var(--color-border-strong); }
.tool-card:focus-visible { outline: none; box-shadow: 0 0 0 3px rgba(17, 24, 39, 0.25); border-color: var(--color-primary); }
.tool-icon { width: 32px; height: 32px; margin-bottom: 16px; color: var(--color-primary); }
.tool-card h3 { margin: 0 0 8px; font-size: 20px; }
.tool-card p { margin: 0 0 14px; color: var(--color-text-secondary); line-height: 1.6; }
.tool-card-badges { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin: 0 0 16px; }
.badge { display: inline-flex; align-items: center; padding: 3px 9px; border-radius: var(--radius-full); background: var(--color-surface); border: 1px solid var(--color-border); color: var(--color-text-secondary); font-size: 12px; font-weight: 600; }
.badge-arrow { color: var(--color-text-muted); font-size: 12px; }
.tool-card span { font-weight: 600; color: var(--color-primary); margin-top: auto; padding-top: 4px; }

.site-footer { margin-top: 64px; padding: 48px 0 24px; border-top: 1px solid var(--color-border); }
.footer-content { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; }
.footer-content h3 { margin-top: 0; font-size: 15px; }
.footer-content a { display: block; margin-bottom: 10px; color: var(--color-text-secondary); }
.footer-bottom { margin-top: 40px; padding-top: 20px; border-top: 1px solid var(--color-border); color: var(--color-text-secondary); font-size: 14px; }