:root {
  --color-bg: #f8fafc;
  --color-surface: #ffffff;
  --color-surface-hover: #ffffff;
  --color-border: #e2e8f0;
  --color-border-hover: #cbd5e1;
  --color-text: #0f172a;
  --color-text-muted: #5b6b80;
  --color-text-subtle: #94a3b8;

  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, 'SFMono-Regular', Menlo, Consolas, monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 10px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);

  --container-width: 1080px;
}

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

html {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: inherit;
  text-decoration: none;
}

.skip-link {
  position: absolute;
  top: -999px;
  left: 20px;
  background: #0f172a;
  color: #ffffff;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  z-index: 1000;
  font-size: 14px;
}

.skip-link:focus {
  top: 16px;
}

.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 20px;
}

/* Header */
.site-header {
  border-bottom: 1px solid var(--color-border);
  background: var(--color-surface);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-inner {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  font-weight: 700;
  font-size: 18px;
  letter-spacing: -0.01em;
}

.brand:focus-visible {
  outline: 2px solid #2563eb;
  outline-offset: 4px;
  border-radius: var(--radius-sm);
}

.brand-icon {
  width: 28px;
  height: 28px;
  border-radius: 7px;
  display: block;
}

.brand-tag {
  font-size: 13px;
  font-weight: 500;
  color: var(--color-text-muted);
  background: #f1f5f9;
  padding: 4px 10px;
  border-radius: var(--radius-full);
}

/* Hero */
.hero {
  padding: 48px 0 36px;
  text-align: center;
}

.hero-title {
  font-size: 32px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--color-text);
  margin-bottom: 12px;
}

@media (min-width: 640px) {
  .hero-title {
    font-size: 40px;
  }
}

.hero-subtitle {
  font-size: 17px;
  color: var(--color-text-muted);
  max-width: 620px;
  margin: 0 auto;
}

/* Tool Grid */
.main-content {
  flex: 1;
  padding-bottom: 64px;
}

.grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

@media (min-width: 640px) {
  .grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 960px) {
  .grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

/* Tool Card */
.tool-card {
  position: relative;
  display: flex;
  flex-direction: column;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 24px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.15s ease, box-shadow 0.15s ease, border-color 0.15s ease;
}

.tool-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
  border-color: var(--card-accent, #2563eb);
}

.tool-card:focus-visible {
  outline: 2px solid var(--card-accent, #2563eb);
  outline-offset: 3px;
}

.card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 16px;
}

.card-icon-wrap {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background-color: var(--card-accent-bg, #eff6ff);
  display: flex;
  align-items: center;
  justify-content: center;
}

.card-icon {
  width: 24px;
  height: 24px;
}

.card-badge {
  font-size: 11px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--card-accent-text, #1d4ed8);
  background: var(--card-accent-bg, #eff6ff);
  padding: 4px 8px;
  border-radius: var(--radius-full);
}

.card-title {
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  color: var(--color-text);
}

.tool-card:hover .card-title {
  color: var(--card-accent, #2563eb);
}

.card-desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.5;
  margin-bottom: 20px;
  flex: 1;
}

.card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 20px;
}

.tag {
  font-size: 12px;
  color: var(--color-text-muted);
  background: #f8fafc;
  border: 1px solid var(--color-border);
  padding: 3px 8px;
  border-radius: var(--radius-sm);
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 13px;
  font-weight: 600;
  color: var(--card-accent, #2563eb);
  padding-top: 14px;
  border-top: 1px solid #f1f5f9;
}

.arrow-icon {
  transition: transform 0.15s ease;
}

.tool-card:hover .arrow-icon {
  transform: translateX(3px);
}

/* Hub-specific accents */
.card-finance {
  --card-accent: #2563eb;
  --card-accent-text: #1d4ed8;
  --card-accent-bg: #eff6ff;
}

.card-math {
  --card-accent: #4f46e5;
  --card-accent-text: #4338ca;
  --card-accent-bg: #eef2ff;
}

.card-cricket {
  --card-accent: #e11d48;
  --card-accent-text: #be123c;
  --card-accent-bg: #fff1f2;
}

.card-construction {
  --card-accent: #d97706;
  --card-accent-text: #b45309;
  --card-accent-bg: #fffbeb;
}

.card-budget {
  --card-accent: #8b5cf6;
  --card-accent-text: #7c3aed;
  --card-accent-bg: #f5f3ff;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--color-border);
  background: var(--color-surface);
  padding: 32px 0 24px;
  margin-top: auto;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  gap: 16px;
  font-size: 13px;
  color: var(--color-text-muted);
}

@media (min-width: 640px) {
  .footer-inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer-note {
  max-width: 520px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  list-style: none;
}

.footer-links a:hover {
  color: var(--color-text);
  text-decoration: underline;
}