/* ────────── RESET & BASE ────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
:root {
  --bg: #0b0d11;
  --surface: #13161b;
  --surface-2: #1a1e26;
  --border: #262b36;
  --text: #e2e4e9;
  --text-muted: #8a8f9d;
  --accent: #6366f1;
  --accent-alt: #818cf8;
  --green: #22c55e;
  --amber: #f59e0b;
  --blue: #3b82f6;
  --radius: 10px;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
  --mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;
}
html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  min-height: 100vh;
}
a { color: var(--accent-alt); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ────────── LAYOUT ────────── */
.container { max-width: 960px; margin: 0 auto; padding: 0 1.25rem; }
.main { padding: 2rem 0 4rem; }

/* ────────── HEADER ────────── */
.header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 1rem 0;
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(12px);
  background: rgba(19,22,27,0.92);
}
.header .container { display: flex; align-items: center; justify-content: space-between; }
.header h1 { font-size: 1.15rem; font-weight: 600; }
.header h1 span { color: var(--accent-alt); }
.header nav { display: flex; gap: 1.5rem; font-size: 0.9rem; }
.header nav a { color: var(--text-muted); transition: color 0.15s; }
.header nav a:hover { color: var(--text); text-decoration: none; }
.header nav a.active { color: var(--accent-alt); }

/* ────────── HERO ────────── */
.hero {
  text-align: center;
  padding: 4rem 0 3rem;
}
.hero h2 { font-size: 2.25rem; font-weight: 700; margin-bottom: 0.75rem; }
.hero p { color: var(--text-muted); font-size: 1.1rem; max-width: 600px; margin: 0 auto 1.5rem; }
.hero-meta {
  display: flex; justify-content: center; gap: 2rem;
  font-size: 0.85rem; color: var(--text-muted);
}
.hero-meta span { display: flex; align-items: center; gap: 0.4rem; }
.badge {
  display: inline-block;
  padding: 0.2rem 0.6rem;
  border-radius: 6px;
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.03em;
}
.badge-green { background: rgba(34,197,94,0.15); color: var(--green); }
.badge-amber { background: rgba(245,158,11,0.15); color: var(--amber); }
.badge-blue { background: rgba(59,130,246,0.15); color: var(--blue); }

/* ────────── WEEK SECTIONS ────────── */
.week-section { margin-bottom: 2.5rem; }
.week-header {
  display: flex; align-items: center; gap: 0.75rem;
  margin-bottom: 1rem; padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border);
}
.week-header h3 { font-size: 1.15rem; font-weight: 600; }
.week-header .week-tag {
  background: var(--surface-2);
  padding: 0.15rem 0.5rem;
  border-radius: 6px;
  font-size: 0.72rem;
  color: var(--text-muted);
}

/* ────────── DAY CARDS (CURRICULUM GRID) ────────── */
.day-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 0.75rem;
}
.day-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1rem 1.15rem;
  transition: border-color 0.15s, transform 0.1s;
  display: flex; flex-direction: column; gap: 0.4rem;
}
.day-card:hover { border-color: var(--accent); transform: translateY(-1px); }
.day-card .day-num {
  font-size: 0.72rem;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.day-card h4 { font-size: 0.95rem; font-weight: 600; }
.day-card .topic { font-size: 0.82rem; color: var(--text-muted); }
.day-card .card-footer {
  display: flex; align-items: center; justify-content: space-between;
  margin-top: auto; padding-top: 0.4rem;
}
.day-card .tags { display: flex; gap: 0.35rem; flex-wrap: wrap; }
.day-card .status-dot {
  width: 8px; height: 8px; border-radius: 50%; flex-shrink: 0;
}
.status-ready { background: var(--green); }
.status-stub { background: var(--amber); box-shadow: 0 0 6px rgba(245,158,11,0.4); }
.status-done { background: var(--blue); }

/* ────────── DAY DETAIL PAGE ────────── */
.day-detail { padding-top: 1rem; }
.day-detail .day-head {
  margin-bottom: 2rem;
  padding-bottom: 1rem;
  border-bottom: 1px solid var(--border);
}
.day-detail .day-head .meta-row {
  display: flex; align-items: center; gap: 1rem; flex-wrap: wrap;
  margin-top: 0.3rem; font-size: 0.85rem; color: var(--text-muted);
}
.day-detail h1 { font-size: 1.75rem; font-weight: 700; margin-bottom: 0.3rem; }
.day-detail h2 {
  font-size: 1.25rem; font-weight: 600;
  margin: 2rem 0 0.75rem;
  padding-bottom: 0.3rem;
  border-bottom: 1px solid var(--border);
}
.day-detail h3 { font-size: 1.05rem; font-weight: 600; margin: 1.5rem 0 0.5rem; }
.day-detail p { margin-bottom: 0.75rem; }
.day-detail ul, .day-detail ol { margin: 0.5rem 0 0.75rem 1.3rem; }
.day-detail li { margin-bottom: 0.3rem; }
.day-detail code {
  font-family: var(--mono);
  font-size: 0.85em;
  background: var(--surface-2);
  padding: 0.15rem 0.4rem;
  border-radius: 4px;
}
.day-detail pre {
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 0.85rem 1rem;
  overflow-x: auto;
  margin: 0.75rem 0;
  font-size: 0.82rem;
  line-height: 1.5;
}
.day-detail pre code {
  background: none;
  padding: 0;
  border-radius: 0;
  font-size: inherit;
}
.day-detail blockquote {
  border-left: 3px solid var(--accent);
  padding: 0.5rem 1rem;
  margin: 0.75rem 0;
  background: var(--surface);
  border-radius: 0 var(--radius) var(--radius) 0;
  color: var(--text-muted);
}
.day-detail hr {
  border: none;
  border-top: 1px solid var(--border);
  margin: 2rem 0;
}
.day-detail table {
  width: 100%;
  border-collapse: collapse;
  margin: 0.75rem 0;
  font-size: 0.85rem;
}
.day-detail th, .day-detail td {
  border: 1px solid var(--border);
  padding: 0.5rem 0.75rem;
  text-align: left;
}
.day-detail th {
  background: var(--surface-2);
  font-weight: 600;
}
.day-detail img { max-width: 100%; border-radius: var(--radius); }

/* ────────── NAV BUTTONS ────────── */
.day-nav {
  display: flex; justify-content: space-between;
  margin-top: 3rem; padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}
.day-nav a {
  display: inline-flex; align-items: center; gap: 0.4rem;
  padding: 0.5rem 1rem;
  background: var(--surface-2);
  border-radius: var(--radius);
  font-size: 0.85rem;
  transition: background 0.15s;
}
.day-nav a:hover { background: var(--border); text-decoration: none; }

/* ────────── STATUS TABLE ────────── */
.status-table { width: 100%; font-size: 0.85rem; margin: 1.5rem 0; }
.status-table th, .status-table td { padding: 0.4rem 0.75rem; text-align: left; border-bottom: 1px solid var(--border); }
.status-table th { font-weight: 600; color: var(--text-muted); font-size: 0.72rem; text-transform: uppercase; letter-spacing: 0.05em; }

/* ────────── ABOUT PAGE ────────── */
.about-section { max-width: 700px; margin: 0 auto; }
.about-section h2 { font-size: 1.55rem; margin: 2rem 0 1rem; }
.about-section .profile-card {
  display: flex; align-items: center; gap: 1rem;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 1rem 1.25rem;
  margin: 0.75rem 0;
}
.profile-card .profile-icon {
  width: 40px; height: 40px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-size: 1.2rem; flex-shrink: 0;
}
.profile-card .profile-name { font-weight: 600; }
.profile-card .profile-desc { font-size: 0.85rem; color: var(--text-muted); }

/* ────────── FOOTER ────────── */
.footer {
  text-align: center; padding: 2rem 0;
  color: var(--text-muted); font-size: 0.8rem;
  border-top: 1px solid var(--border);
}

/* ────────── RESPONSIVE ────────── */
@media (max-width: 640px) {
  .hero h2 { font-size: 1.6rem; }
  .day-grid { grid-template-columns: 1fr; }
  .hero-meta { flex-direction: column; align-items: center; gap: 0.5rem; }
  .header .container { flex-direction: column; gap: 0.5rem; }
}