/* ===== Hero ===== */
.hero {
  background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
  padding: 5rem 2rem 4rem;
  text-align: center;
  color: #ffffff;
}

.hero-eyebrow {
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: #4cc9f0;
  margin-bottom: 1rem;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 1rem;
  line-height: 1.1;
}

.hero-title .accent {
  color: #4361ee;
}

.hero-sub {
  font-size: 1.05rem;
  color: rgba(255, 255, 255, 0.65);
  max-width: 480px;
  margin: 0 auto 2.5rem;
  line-height: 1.6;
}

.hero-stats {
  display: flex;
  gap: 2.5rem;
  justify-content: center;
  flex-wrap: wrap;
}

.stat-num {
  display: block;
  font-size: 1.8rem;
  font-weight: 800;
  color: #4cc9f0;
  line-height: 1;
}

.stat-label {
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.5);
  margin-top: 0.3rem;
}

/* ===== Weeks Section ===== */
.weeks-section {
  padding: 3rem 2rem;
  flex: 1;
  max-width: 900px;
  margin: 0 auto;
  width: 100%;
}

.section-title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--border);
}

.weeks-list {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

/* ===== Week Card ===== */
.week-card {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 16px;
  padding: 1.5rem 1.75rem;
  display: flex;
  align-items: center;
  gap: 1.5rem;
  box-shadow: 0 2px 12px var(--shadow);
  transition: box-shadow 0.25s ease, border-color 0.25s ease, transform 0.2s ease;
}

.week-card--active:hover {
  box-shadow: 0 6px 24px var(--shadow-hover);
  border-color: rgba(67, 97, 238, 0.4);
  transform: translateY(-2px);
}

.week-card--soon {
  opacity: 0.6;
}

.week-card--empty {
  opacity: 0.5;
  cursor: default;
}

.week-card--empty .week-badge {
  background: linear-gradient(135deg, #a09070, #c8b090);
}

/* ===== Week Badge ===== */
.week-badge {
  width: 52px;
  height: 52px;
  border-radius: 14px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  font-weight: 800;
  color: #ffffff;
  flex-shrink: 0;
  letter-spacing: -0.02em;
}

.week-card--active .week-badge {
  background: linear-gradient(135deg, #4361ee, #4cc9f0);
}

.week-card--soon .week-badge {
  background: linear-gradient(135deg, #718096, #a0aec0);
}

/* ===== Week Info ===== */
.week-info {
  flex: 1;
}

.week-label {
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.3rem;
}

.week-card--soon .week-label {
  color: var(--text-secondary);
}

.week-title {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.65rem;
  line-height: 1.4;
}

.week-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
}

.wtag {
  display: inline-flex;
  padding: 0.18rem 0.6rem;
  border-radius: 5px;
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.wtag-html     { background: rgba(67, 97, 238, 0.1); color: var(--tag-html); }
.wtag-css      { background: rgba(123, 45, 139, 0.1); color: var(--tag-css); }
.wtag-boxmodel { background: rgba(26, 127, 75, 0.1); color: var(--tag-boxmodel); }
.wtag-exam     { background: rgba(160, 100, 0, 0.1); color: #a06400; }

/* ===== Week Actions ===== */
.week-actions {
  display: flex;
  gap: 0.6rem;
  flex-shrink: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.5rem 1.15rem;
  border-radius: 8px;
  font-size: 0.82rem;
  font-weight: 600;
  text-decoration: none;
  transition: opacity 0.2s, transform 0.15s;
  white-space: nowrap;
}

.btn:hover {
  opacity: 0.85;
  transform: translateY(-1px);
}

.btn-study {
  background: rgba(67, 97, 238, 0.1);
  color: var(--accent);
  border: 1.5px solid rgba(67, 97, 238, 0.25);
}

.btn-quiz {
  background: var(--accent);
  color: #ffffff;
}

.coming-soon-badge {
  display: inline-flex;
  padding: 0.45rem 1.1rem;
  border-radius: 8px;
  font-size: 0.78rem;
  font-weight: 600;
  background: var(--bg);
  color: var(--text-secondary);
  border: 1.5px solid var(--border);
}

/* ===== Dark Mode Adjustments ===== */
#dark-mode:checked ~ .site-wrapper .wtag-html     { background: rgba(67, 97, 238, 0.2); }
#dark-mode:checked ~ .site-wrapper .wtag-css      { background: rgba(123, 45, 139, 0.2); }
#dark-mode:checked ~ .site-wrapper .wtag-boxmodel { background: rgba(26, 127, 75, 0.2); }
#dark-mode:checked ~ .site-wrapper .btn-study {
  background: rgba(67, 97, 238, 0.18);
  border-color: rgba(67, 97, 238, 0.4);
}

/* ===== Responsive ===== */
@media (max-width: 640px) {
  .hero {
    padding: 3rem 1rem 2.5rem;
  }

  .weeks-section {
    padding: 2rem 1rem;
  }

  .week-card {
    flex-wrap: wrap;
    gap: 1rem;
    padding: 1.25rem;
  }

  .week-actions {
    width: 100%;
  }

  .btn {
    flex: 1;
  }
}