/* ===============================
   css/global.css
================================== */
:root {
  --color-brand: #0f172a;
  --color-brand-light: #1e293b;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-text-main: #334155;
  --color-text-muted: #64748b;
  --color-bg-page: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-border: #e2e8f0;

  --font-sans: 'Inter', system-ui, sans-serif;
  --font-mono: 'Fira Code', monospace;

  --layout-max-width: 1100px;
  --header-height: 72px;
}

* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  color: var(--color-text-main);
  background-color: var(--color-bg-page);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

main { flex: 1; }

.container {
  max-width: var(--layout-max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Typography & Links */
h1, h2, h3, h4 { color: var(--color-brand); font-weight: 700; line-height: 1.2; }
p { margin-bottom: 1rem; }
a { color: var(--color-accent); text-decoration: none; transition: color 0.2s; }
a:hover { color: var(--color-accent-hover); }

/* Buttons */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.75rem 1.5rem; border-radius: 6px; font-weight: 500;
  font-size: 0.95rem; transition: background-color 0.2s, border-color 0.2s;
  cursor: pointer; border: 1px solid transparent; font-family: inherit;
}
.btn-primary { background-color: var(--color-accent); color: #ffffff; }
.btn-primary:hover { background-color: var(--color-accent-hover); color: #ffffff; }
.btn-outline { background-color: transparent; border-color: var(--color-border); color: var(--color-brand); }
.btn-outline:hover { border-color: var(--color-brand); background-color: var(--color-bg-alt); }

/* Sections */
.section { padding: 5rem 0; }
.section-alt { background-color: var(--color-bg-alt); border-top: 1px solid var(--color-border); border-bottom: 1px solid var(--color-border); }
.section-header { text-align: center; margin-bottom: 4rem; max-width: 750px; margin-inline: auto; }
.section-title { font-size: 2.25rem; margin-bottom: 1rem; }
.section-subtitle { color: var(--color-text-muted); font-size: 1.1rem; }

/* Header & Nav */
.site-header {
  position: sticky; top: 0; z-index: 1000; height: var(--header-height);
  background-color: rgba(255, 255, 255, 0.95); backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border); display: flex; align-items: center;
}
.nav-container { display: flex; justify-content: space-between; align-items: center; width: 100%; }
.brand-logo { font-size: 1.25rem; font-weight: 700; color: var(--color-brand); display: flex; align-items: center; gap: 0.25rem; }
.nav-links { display: flex; gap: 2rem; list-style: none; }
.nav-links a { color: var(--color-text-main); font-weight: 500; font-size: 0.95rem; }
.nav-links a:hover { color: var(--color-accent); }
.mobile-menu-btn { display: none; background: none; border: none; font-size: 1.5rem; cursor: pointer; color: var(--color-brand); }

/* Mobile Menu */
.mobile-nav {
  position: fixed; top: var(--header-height); left: 0; width: 100%;
  height: calc(100vh - var(--header-height)); background-color: var(--color-bg-page);
  padding: 2rem; transform: translateX(100%); transition: transform 0.3s ease;
  z-index: 999; border-top: 1px solid var(--color-border);
}
.mobile-nav.active { transform: translateX(0); }
.mobile-nav-links { list-style: none; display: flex; flex-direction: column; gap: 1.5rem; }
.mobile-nav-links a { font-size: 1.25rem; color: var(--color-brand); font-weight: 600; }

/* Footer */
.site-footer { text-align: center; padding: 2rem 0; border-top: 1px solid var(--color-border); color: var(--color-text-muted); font-size: 0.9rem; background-color: var(--color-bg-page); }
.footer-links { display: flex; justify-content: center; gap: 1rem; margin-bottom: 1rem; flex-wrap: wrap; }
.footer-links a { color: var(--color-text-muted); font-weight: 500; }
.footer-links a:hover { color: var(--color-accent); }

/* Responsive Base */
@media (max-width: 768px) {
  .nav-links { display: none; }
  .mobile-menu-btn { display: block; }
  .section { padding: 3rem 0; }
}