.app-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--border-subtle);
  background: rgba(2, 6, 23, 0.92);
  backdrop-filter: blur(12px);
}

.header-inner {
  max-width: 72rem;
  margin: 0 auto;
  padding: 0.875rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.brand-row {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.brand-icon {
  width: 2.35rem;
  height: 2.35rem;
  border-radius: 0.75rem;
  background: rgba(79, 70, 229, 0.2);
  color: #818cf8;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.05rem;
  flex-shrink: 0;
}

.brand-title {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 700;
  color: #ffffff;
  line-height: 1.25;
}

.brand-subtitle {
  margin: 0;
  font-size: 0.75rem;
  color: var(--text-muted);
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}

.month-select-wrap {
  display: flex;
  align-items: center;
  gap: 0.4rem;
  border: 1px solid var(--border-input);
  background: var(--bg-card);
  border-radius: 0.75rem;
  padding: 0.35rem 0.65rem;
}

.month-select-wrap i {
  color: #818cf8;
  font-size: 0.85rem;
}

.month-select {
  border: none;
  background: transparent;
  color: #ffffff;
  font-size: 0.8125rem;
  outline: none;
  padding-right: 0.25rem;
}

.month-select option {
  background: #0f172a;
  color: #ffffff;
}

.header-tabs {
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1rem;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.25rem;
}

.tab-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.45rem;
  border: none;
  border-bottom: 2px solid transparent;
  background: transparent;
  padding: 0.65rem 0.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-muted);
  transition: color 0.15s ease, border-color 0.15s ease;
}

.tab-btn:hover {
  color: #e2e8f0;
}

.tab-btn.active {
  color: #ffffff;
  border-bottom-color: #6366f1;
}

.tab-badge-mobile {
  border-radius: 9999px;
  background: #1e293b;
  color: #e2e8f0;
  padding: 0.1rem 0.45rem;
  font-size: 0.65rem;
  font-weight: 600;
}

.tab-label-pc {
  display: none;
}

@media (min-width: 1025px) {
  .header-inner {
    flex-direction: row;
    align-items: center;
    justify-content: space-between;
  }

  .header-tabs {
    display: flex;
    gap: 0.35rem;
  }

  .tab-btn {
    justify-content: flex-start;
    padding: 0.65rem 1rem;
  }

  .tab-badge-mobile {
    display: none;
  }

  .tab-label-pc {
    display: inline;
  }
}