.trip-detail {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  background: var(--color-bg-secondary);
}

/* Header */
.trip-detail-header {
  background: var(--color-bg-primary);
  border-bottom: 1px solid var(--color-border);
  padding: var(--spacing-md) var(--spacing-xl) var(--spacing-lg);
  box-shadow: var(--shadow-sm);
}

.header-nav {
  margin-bottom: 1rem;
}

.btn-back {
  color: var(--color-text-secondary);
  text-decoration: none;
  font-size: 0.9rem;
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  transition: color var(--transition-normal);
}

.btn-back:hover {
  color: var(--color-text-primary);
}

.header-content h1 {
  margin: 0 0 0.5rem 0;
  font-size: 2rem;
  color: var(--color-text-primary);
}

.trip-description {
  color: var(--color-text-secondary);
  margin: 0 0 1rem 0;
  font-size: 1.1rem;
}

.trip-dates {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: 0.95rem;
}

.date-label {
  color: var(--color-text-muted);
  font-weight: 500;
}

.date-value {
  color: var(--color-text-primary);
}

.date-separator {
  color: var(--color-text-light);
  margin: 0 0.5rem;
}

/* Content Layout */
.trip-detail-content {
  flex: 1;
  display: flex;
  gap: 0;
  height: calc(100vh - var(--header-height));
}

.trip-detail-sidebar {
  width: var(--sidebar-width);
  background: var(--color-bg-primary);
  border-right: 1px solid var(--color-border);
  overflow-y: auto;
}

.trip-detail-main {
  flex: 1;
  padding: var(--spacing-xl);
  overflow-y: auto;
}

/* Calendar Placeholder */
.calendar-placeholder {
  background: var(--color-bg-primary);
  border-radius: var(--border-radius-lg);
  padding: var(--spacing-xl);
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.calendar-placeholder h2 {
  color: var(--color-text-primary);
  margin: 0 0 1rem 0;
}

.calendar-placeholder p {
  color: var(--color-text-muted);
}

/* Loading State */
.trip-detail-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  gap: var(--spacing-md);
}

.spinner {
  width: 40px;
  height: 40px;
  border: 3px solid #f3f3f3;
  border-top: 3px solid #333;
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Error State */
.trip-detail-error {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  gap: var(--spacing-md);
}

.trip-detail-error h2 {
  color: var(--color-danger);
  margin: 0;
}

.trip-detail-error p {
  color: var(--color-text-secondary);
  margin: 0;
}

.trip-detail-error .btn-back {
  margin-top: 1rem;
  padding: var(--spacing-sm) var(--spacing-md);
  background: #333;
  color: white;
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  transition: background var(--transition-normal);
}

.trip-detail-error .btn-back:hover {
  background: #555;
}

/* Responsive */
@media (max-width: 768px) {
  .trip-detail-content {
    flex-direction: column;
    height: auto;
  }

  .trip-detail-sidebar {
    width: 100%;
    border-right: none;
    border-bottom: 1px solid var(--color-border);
    min-height: 400px;
  }

  .trip-detail-main {
    padding: var(--spacing-md);
  }

  .trip-detail-header {
    padding: var(--spacing-md);
  }

  .header-content h1 {
    font-size: 1.5rem;
  }
}