/* ============================================================
   BST236 Coding Blog — Global Stylesheet
   ============================================================ */

/* ---------- Google Fonts ---------- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&family=Fira+Code:wght@400;500&display=swap');

/* ---------- CSS Variables ---------- */
:root {
  --color-primary: #6366f1;
  --color-primary-light: #818cf8;
  --color-primary-dark: #4f46e5;
  --color-accent: #22d3ee;
  --color-bg: #0f172a;
  --color-bg-secondary: #1e293b;
  --color-sidebar: #1e293b;
  --color-header: #0f172a;
  --color-text: #e2e8f0;
  --color-text-muted: #94a3b8;
  --color-border: #334155;
  --color-card: #1e293b;
  --color-card-hover: #334155;
  --color-link: #818cf8;
  --color-link-hover: #a5b4fc;
  --sidebar-width: 240px;
  --header-height: 64px;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'Fira Code', 'Consolas', monospace;
  --radius: 10px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --transition: 0.25s ease;
}

/* ---------- Reset & Base ---------- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.7;
  min-height: 100vh;
}

a {
  color: var(--color-link);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--color-link-hover);
}

/* ---------- Header ---------- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--color-header);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(15, 23, 42, 0.85);
}

.header__title {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.5px;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ---------- Sidebar ---------- */
.sidebar {
  position: fixed;
  top: var(--header-height);
  left: 0;
  bottom: 0;
  width: var(--sidebar-width);
  background: var(--color-sidebar);
  border-right: 1px solid var(--color-border);
  padding: 2rem 0;
  overflow-y: auto;
  z-index: 90;
}

.sidebar__list {
  list-style: none;
}

.sidebar__link {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1.5rem;
  color: var(--color-text-muted);
  font-size: 0.95rem;
  font-weight: 500;
  transition: all var(--transition);
  border-left: 3px solid transparent;
}

.sidebar__link:hover {
  color: var(--color-text);
  background: rgba(99, 102, 241, 0.08);
  border-left-color: var(--color-primary-light);
}

.sidebar__link.active {
  color: var(--color-primary-light);
  background: rgba(99, 102, 241, 0.12);
  border-left-color: var(--color-primary);
  font-weight: 600;
}

.sidebar__icon {
  font-size: 1.15rem;
  width: 1.5rem;
  text-align: center;
  flex-shrink: 0;
}

/* ---------- Main Content ---------- */
.content {
  margin-left: var(--sidebar-width);
  margin-top: var(--header-height);
  padding: 2.5rem 3rem 4rem;
  min-height: calc(100vh - var(--header-height));
}

/* ---------- Hero Section ---------- */
.hero {
  text-align: center;
  padding: 3rem 0 2.5rem;
}

.hero__title {
  font-size: 2.4rem;
  font-weight: 700;
  margin-bottom: 1rem;
  background: linear-gradient(135deg, var(--color-primary-light), var(--color-accent));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subtitle {
  font-size: 1.1rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
  line-height: 1.8;
}

/* ---------- Section ---------- */
.section {
  margin-bottom: 3rem;
}

.section__title {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: 1.25rem;
  padding-bottom: 0.5rem;
  border-bottom: 2px solid var(--color-border);
  color: var(--color-text);
}

/* ---------- Cards Grid ---------- */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 1.5rem;
}

.card {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  transition: all var(--transition);
  display: flex;
  flex-direction: column;
}

.card:hover {
  background: var(--color-card-hover);
  transform: translateY(-4px);
  box-shadow: var(--shadow);
  border-color: var(--color-primary);
}

.card__icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.card__title {
  font-size: 1.15rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  color: var(--color-text);
}

.card__desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.6;
  flex-grow: 1;
}

.card__link {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 1rem;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-primary-light);
}

.card__link:hover {
  color: var(--color-accent);
}

/* ---------- Page Header ---------- */
.page-header {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 2px solid var(--color-border);
}

.page-header__title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: 0.5rem;
}

.page-header__desc {
  font-size: 1rem;
  color: var(--color-text-muted);
}

/* ---------- Content Prose ---------- */
.prose {
  max-width: 800px;
}

.prose p {
  margin-bottom: 1rem;
  color: var(--color-text-muted);
  line-height: 1.8;
}

.prose h3 {
  font-size: 1.2rem;
  font-weight: 600;
  margin: 1.5rem 0 0.75rem;
  color: var(--color-text);
}

.prose ul {
  margin-left: 1.5rem;
  margin-bottom: 1rem;
}

.prose li {
  margin-bottom: 0.4rem;
  color: var(--color-text-muted);
}

/* ---------- Tag / Badge ---------- */
.badge {
  display: inline-block;
  padding: 0.2rem 0.7rem;
  font-size: 0.75rem;
  font-weight: 600;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge--coming {
  background: rgba(99, 102, 241, 0.15);
  color: var(--color-primary-light);
  border: 1px solid rgba(99, 102, 241, 0.3);
}

.badge--live {
  background: rgba(34, 211, 238, 0.15);
  color: var(--color-accent);
  border: 1px solid rgba(34, 211, 238, 0.3);
}

/* ---------- Footer ---------- */
.footer {
  margin-left: var(--sidebar-width);
  padding: 1.5rem 3rem;
  text-align: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--color-border);
}

.footer a {
  color: var(--color-primary-light);
}

/* ---------- Mobile Menu Toggle ---------- */
.menu-toggle {
  display: none;
  position: fixed;
  top: 14px;
  left: 16px;
  z-index: 200;
  background: var(--color-primary);
  color: #fff;
  border: none;
  border-radius: 8px;
  width: 36px;
  height: 36px;
  font-size: 1.2rem;
  cursor: pointer;
  align-items: center;
  justify-content: center;
}

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .menu-toggle {
    display: flex;
  }

  .header__title {
    font-size: 1.1rem;
  }

  .sidebar {
    transform: translateX(-100%);
    transition: transform var(--transition);
  }

  .sidebar.open {
    transform: translateX(0);
  }

  .content {
    margin-left: 0;
    padding: 2rem 1.25rem 3rem;
  }

  .footer {
    margin-left: 0;
    padding: 1.5rem 1.25rem;
  }

  .hero__title {
    font-size: 1.7rem;
  }

  .cards {
    grid-template-columns: 1fr;
  }
}