/* Project ATLAS - Site #29: Conversor de Unidades (Spanish Utility) */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@300;400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600;700&display=swap');

:root {
  --bg-primary: #0f172a;
  --bg-surface: #1e293b;
  --bg-card: #334155;
  --border-subtle: #475569;
  --border-focus: #38bdf8;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --accent-sky: #38bdf8;
  --accent-blue: #3b82f6;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  font-family: var(--font-sans);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}
.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 1.5rem;
  width: 100%;
}
header {
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(30, 41, 59, 0.85);
  backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 50;
}
.header-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 4.25rem;
}
.logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  color: var(--text-primary);
  font-weight: 800;
  font-size: 1.25rem;
}
.logo-icon {
  width: 2.25rem;
  height: 2.25rem;
  background: linear-gradient(135deg, var(--accent-sky), var(--accent-blue));
  border-radius: 0.6rem;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  color: #0f172a;
}
nav { display: flex; gap: 1.5rem; }
nav a {
  text-decoration: none;
  color: var(--text-secondary);
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}
nav a:hover, nav a.active { color: var(--text-primary); }

main { flex: 1; padding: 2.5rem 0; }
.hero-title {
  font-size: 2.5rem;
  font-weight: 800;
  text-align: center;
  margin-bottom: 0.75rem;
  background: linear-gradient(135deg, #ffffff 40%, var(--accent-sky) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-subtitle {
  text-align: center;
  color: var(--text-secondary);
  max-width: 680px;
  margin: 0 auto 2rem;
  font-size: 1.05rem;
}

/* Category Tabs */
.category-tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.5rem;
  margin-bottom: 2rem;
}
.cat-tab {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  padding: 0.6rem 1rem;
  border-radius: 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
}
.cat-tab.active {
  background: var(--accent-sky);
  color: #0f172a;
  border-color: var(--accent-sky);
}

/* Card & Layout */
.converter-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 1rem;
  padding: 2rem;
  box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
  max-width: 800px;
  margin: 0 auto 3rem;
}
.converter-grid {
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  gap: 1rem;
  align-items: center;
  margin-bottom: 1.5rem;
}
@media (max-width: 640px) {
  .converter-grid { grid-template-columns: 1fr; }
}

.swap-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  color: var(--accent-sky);
  width: 3rem;
  height: 3rem;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  transition: all 0.2s;
  align-self: center;
  margin: 0 auto;
}
.swap-btn:hover {
  background: var(--accent-sky);
  color: #0f172a;
  transform: rotate(180deg);
}

.unit-box {
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
  border-radius: 0.75rem;
  padding: 1rem;
}
.unit-box select {
  width: 100%;
  background: transparent;
  border: none;
  color: #fff;
  font-weight: 700;
  font-size: 1.05rem;
  cursor: pointer;
  outline: none;
  margin-bottom: 0.5rem;
}
.unit-box select option {
  background: var(--bg-surface);
  color: #fff;
}
.unit-box input {
  width: 100%;
  background: transparent;
  border: none;
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: #fff;
  outline: none;
}

/* Result banner */
.result-banner {
  background: linear-gradient(135deg, rgba(56, 189, 248, 0.1), rgba(59, 130, 246, 0.1));
  border: 1px solid rgba(56, 189, 248, 0.3);
  border-radius: 0.75rem;
  padding: 1.25rem;
  text-align: center;
  margin-bottom: 1.5rem;
}
.result-formula {
  font-size: 1.15rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: var(--accent-sky);
}
.result-sub {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-top: 0.35rem;
}

/* Quick Table */
.conversion-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.9rem;
  margin-top: 1.5rem;
}
.conversion-table th, .conversion-table td {
  padding: 0.65rem;
  text-align: left;
  border-bottom: 1px solid var(--border-subtle);
}
.conversion-table th { color: var(--accent-sky); font-weight: 700; }
.conversion-table td:last-child {
  text-align: right;
  font-family: var(--font-mono);
  font-weight: 600;
}

/* Ads Slot */
.ad-slot {
  background: rgba(30, 41, 59, 0.5);
  border: 1px dashed var(--border-subtle);
  border-radius: 0.75rem;
  padding: 1.5rem;
  text-align: center;
  color: var(--text-secondary);
  font-size: 0.85rem;
  margin: 2.5rem 0;
}

/* Article Area */
.article-content {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 1rem;
  padding: 2.5rem;
  margin-bottom: 3rem;
}
.article-content h2 {
  font-size: 1.75rem;
  font-weight: 800;
  margin: 2rem 0 1rem;
  color: var(--text-primary);
  border-bottom: 1px solid var(--border-subtle);
  padding-bottom: 0.5rem;
}
.article-content h2:first-child { margin-top: 0; }
.article-content h3 {
  font-size: 1.3rem;
  font-weight: 700;
  margin: 1.5rem 0 0.75rem;
  color: var(--accent-sky);
}
.article-content p, .article-content ul, .article-content ol {
  color: #cbd5e1;
  margin-bottom: 1.25rem;
  line-height: 1.75;
}
.article-content ul, .article-content ol { padding-left: 1.5rem; }
.article-content li { margin-bottom: 0.5rem; }
.info-box {
  background: rgba(56, 189, 248, 0.1);
  border-left: 4px solid var(--accent-sky);
  padding: 1rem 1.25rem;
  border-radius: 0 0.5rem 0.5rem 0;
  margin: 1.5rem 0;
}

/* Blog Cards */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 1.5rem;
  margin-top: 1.5rem;
}
.blog-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: 0.85rem;
  padding: 1.5rem;
  text-decoration: none;
  color: inherit;
  transition: transform 0.2s, border-color 0.2s;
  display: flex;
  flex-direction: column;
}
.blog-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-sky);
}
.blog-card h3 {
  font-size: 1.15rem;
  font-weight: 700;
  color: #fff;
  margin-bottom: 0.75rem;
}
.blog-card p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  flex: 1;
}
.blog-readmore {
  color: var(--accent-sky);
  font-size: 0.85rem;
  font-weight: 600;
  margin-top: 1rem;
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
}

/* Footer */
footer {
  background: rgba(15, 23, 42, 0.95);
  border-top: 1px solid var(--border-subtle);
  padding: 3rem 0 2rem;
  font-size: 0.9rem;
  color: var(--text-secondary);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 2rem;
  margin-bottom: 2rem;
}
.footer-links {
  display: flex;
  gap: 1.5rem;
  flex-wrap: wrap;
}
.footer-links a {
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-links a:hover { color: #fff; }
.footer-bottom {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}