/* Dark pastel purple theme */
:root {
  --bg: #1f102d;          /* deep purple-black */
  --panel: #2a1740;       /* slightly lighter */
  --panel-2: #301b4a;     /* card tint */
  --text: #eadff7;        /* soft near-white */
  --muted: #c8b9e6;       /* muted text */
  --primary: #9b8dd3;     /* pastel purple */
  --primary-600: #8b7bc8; /* hover */
  --primary-700: #7b6bbc; /* active */
  --accent: #c39be4;      /* lilac accent */
  --success: #9bd3b4;     /* mint success */
  --shadow: 0 10px 30px rgba(0,0,0,0.35);
  --radius: 14px;
}

* { box-sizing: border-box; }
html, body { height: 100%; }

body {
  margin: 0;
  font-family: "Poppins", system-ui, -apple-system, Segoe UI, Roboto, Arial, sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 800px at 10% 10%, #2a1740, transparent),
              radial-gradient(900px 700px at 90% 0%, #2b1842, transparent),
              var(--bg);
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(6px);
  background: linear-gradient(180deg, rgba(32,16,45,0.85), rgba(32,16,45,0));
  border-bottom: 1px solid rgba(255,255,255,0.06);
}
.site-header h1 {
  margin: 0;
  padding: 22px 20px;
  font-weight: 700;
  letter-spacing: 0.6px;
}

.container {
  max-width: 1000px;
  margin: 24px auto 60px;
  padding: 0 16px;
}

.weeks {
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.02));
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.weeks-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 18px 0;
}
.weeks-header h2 { margin: 0 0 12px; font-size: 1.1rem; color: var(--muted); }

.weeks-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  padding: 16px 18px 20px;
}

@media (min-width: 520px) {
  .weeks-grid { grid-template-columns: repeat(3, 1fr); }
}
@media (min-width: 760px) {
  .weeks-grid { grid-template-columns: repeat(4, 1fr); }
}

.week-btn {
  appearance: none;
  border: 1px solid rgba(255,255,255,0.12);
  background: linear-gradient(180deg, rgba(155,141,211,0.18), rgba(155,141,211,0.08));
  color: var(--text);
  border-radius: 12px;
  padding: 12px 14px;
  font-weight: 600;
  transition: transform 0.12s ease, box-shadow 0.2s ease, background 0.2s ease, border-color 0.2s ease;
  box-shadow: 0 6px 14px rgba(0,0,0,0.28);
  cursor: pointer;
}
.week-btn:hover {
  background: linear-gradient(180deg, rgba(155,141,211,0.24), rgba(155,141,211,0.12));
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(0,0,0,0.35);
}
.week-btn:active {
  transform: translateY(0);
  background: linear-gradient(180deg, rgba(155,141,211,0.3), rgba(155,141,211,0.16));
}
.week-btn:focus-visible {
  outline: none;
  box-shadow: 0 0 0 4px rgba(195,155,228,0.35), 0 8px 18px rgba(0,0,0,0.3);
}
.week-btn.active {
  border-color: var(--accent);
  background: linear-gradient(180deg, rgba(195,155,228,0.28), rgba(155,141,211,0.18));
}

.content {
  margin-top: 18px;
  padding: 18px;
  background: linear-gradient(180deg, rgba(255,255,255,0.04), rgba(255,255,255,0.02));
  border: 1px solid rgba(255,255,255,0.08);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.viewer {
  position: relative;
  border-radius: 12px;
  overflow: hidden;
  border: 1px solid rgba(255,255,255,0.08);
  background: linear-gradient(180deg, rgba(48,27,74,0.5), rgba(42,23,64,0.5));
}

.viewer iframe {
  width: 100%;
  height: min(72vh, 900px);
  border: none;
  background: #0e0b12;
}

.placeholder { color: var(--muted); }
.placeholder h3 { margin: 6px 0 8px; color: var(--text); }

.week-card {
  background: linear-gradient(180deg, rgba(48,27,74,0.7), rgba(42,23,64,0.7));
  border: 1px solid rgba(255,255,255,0.10);
  border-radius: 12px;
  padding: 16px;
}
.week-card h3 { margin: 0 0 10px; color: var(--accent); }
.week-card p { margin: 0; color: var(--muted); }

.site-footer {
  text-align: center;
  color: var(--muted);
  padding: 28px 16px 40px;
}