/* CSS Variables for theming */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f3f4f6;
  --bg-tertiary: #e5e7eb;
  --text-primary: #111827;
  --text-secondary: #6b7280;
  --text-tertiary: #9ca3af;
  --border-color: #e5e7eb;
  --shadow: rgba(0, 0, 0, 0.1);
  --shadow-lg: rgba(0, 0, 0, 0.15);

  /* Brand colors */
  --primary: #2563eb;
  --primary-hover: #1d4ed8;
  --primary-light: #dbeafe;

  /* Entry type colors */
  --homework: #3b82f6;
  --exam: #ef4444;
  --event: #10b981;
  --reminder: #f59e0b;
  --other: #6b7280;

  /* Status colors */
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --info: #3b82f6;
}

[data-theme="dark"] {
  --bg-primary: #111827;
  --bg-secondary: #1f2937;
  --bg-tertiary: #374151;
  --text-primary: #f9fafb;
  --text-secondary: #d1d5db;
  --text-tertiary: #9ca3af;
  --border-color: #374151;
  --shadow: rgba(0, 0, 0, 0.3);
  --shadow-lg: rgba(0, 0, 0, 0.5);

  --primary-light: #1e3a8a;
}

/* Reset and base styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* Container */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem;
}

/* Header */
.app-header {
  background-color: var(--bg-primary);
  border-bottom: 1px solid var(--border-color);
  padding: 1rem;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 4px var(--shadow);
}

.header-content {
  max-width: 1200px;
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.app-title {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--primary);
}

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

/* Buttons */
.btn {
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 0.375rem;
  font-size: 0.875rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  white-space: nowrap;
}

.btn-primary {
  background-color: var(--primary);
  color: white;
}

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

.btn-secondary {
  background-color: var(--bg-tertiary);
  color: var(--text-primary);
}

.btn-secondary:hover {
  background-color: var(--border-color);
}

.btn-danger {
  background-color: var(--error);
  color: white;
}

.btn-danger:hover {
  background-color: #dc2626;
}

.btn-small {
  padding: 0.25rem 0.5rem;
  font-size: 0.75rem;
}

.btn-icon {
  padding: 0.5rem;
  background: transparent;
  border: none;
  color: var(--text-secondary);
  cursor: pointer;
  border-radius: 0.375rem;
  transition: all 0.2s;
}

.btn-icon:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

/* Login Page */
.login-container {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.login-card {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  box-shadow: 0 4px 6px var(--shadow-lg);
  padding: 2rem;
  width: 100%;
  max-width: 400px;
}

.login-title {
  font-size: 1.875rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 2rem;
  color: var(--primary);
}

.form-group {
  margin-bottom: 1rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.5rem;
  color: var(--text-secondary);
}

.form-input {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 0.375rem;
  font-size: 1rem;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  transition: border-color 0.2s;
}

.form-input:focus {
  outline: none;
  border-color: var(--primary);
}

/* Alert messages */
.alert {
  padding: 0.75rem 1rem;
  border-radius: 0.375rem;
  margin-bottom: 1rem;
  font-size: 0.875rem;
}

.alert-error {
  background-color: #fee2e2;
  color: #991b1b;
  border: 1px solid #fecaca;
}

[data-theme="dark"] .alert-error {
  background-color: #7f1d1d;
  color: #fecaca;
  border-color: #991b1b;
}

.alert-warning {
  background-color: #fef3c7;
  color: #92400e;
  border: 1px solid #fde68a;
}

[data-theme="dark"] .alert-warning {
  background-color: #78350f;
  color: #fde68a;
  border-color: #92400e;
}

.alert-info {
  background-color: #dbeafe;
  color: #1e40af;
  border: 1px solid #bfdbfe;
}

[data-theme="dark"] .alert-info {
  background-color: #1e3a8a;
  color: #bfdbfe;
  border-color: #1e40af;
}

/* Week Navigation */
.week-nav {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  padding: 1rem;
  margin-bottom: 1rem;
  box-shadow: 0 1px 3px var(--shadow);
}

.week-nav-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  flex-wrap: wrap;
}

.week-info {
  font-size: 1.125rem;
  font-weight: 600;
  text-align: center;
  flex: 1;
  min-width: 200px;
}

.week-buttons {
  display: flex;
  gap: 0.5rem;
}

/* Group Filter */
.group-filter {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  padding: 1rem;
  margin-bottom: 1rem;
  box-shadow: 0 1px 3px var(--shadow);
}

.group-filter-title {
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 0.75rem;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.group-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.group-chip {
  padding: 0.375rem 0.75rem;
  border-radius: 1rem;
  font-size: 0.875rem;
  border: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  cursor: pointer;
  transition: all 0.2s;
  user-select: none;
}

.group-chip:hover {
  background-color: var(--bg-tertiary);
}

.group-chip.active {
  background-color: var(--primary);
  color: white;
  border-color: var(--primary);
}

/* Calendar Grid */
.calendar {
  display: grid;
  gap: 1rem;
  margin-bottom: 2rem;
}

/* Mobile: Stack days vertically */
@media (max-width: 768px) {
  .calendar {
    grid-template-columns: 1fr;
  }
}

/* Desktop: Days in columns */
@media (min-width: 769px) {
  .calendar {
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  }
}

.day-column {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  overflow: hidden;
  box-shadow: 0 1px 3px var(--shadow);
}

.day-header {
  background-color: var(--primary);
  color: white;
  padding: 0.75rem 1rem;
  font-weight: 600;
  text-align: center;
}

.day-header.today {
  background-color: var(--success);
}

.day-header.weekend {
  background-color: var(--text-secondary);
}

.day-entries {
  padding: 0.5rem;
  min-height: 100px;
}

/* Entry Cards */
.entry-card {
  background-color: var(--bg-secondary);
  border-left: 4px solid var(--primary);
  border-radius: 0.375rem;
  padding: 0.75rem;
  margin-bottom: 0.5rem;
  cursor: pointer;
  transition: all 0.2s;
  position: relative;
}

.entry-card:hover {
  box-shadow: 0 2px 4px var(--shadow);
  transform: translateY(-1px);
}

.entry-card.deleted {
  opacity: 0.6;
  text-decoration: line-through;
}

.entry-card[data-type="HOMEWORK"] {
  border-left-color: var(--homework);
}

.entry-card[data-type="EXAM"] {
  border-left-color: var(--exam);
}

.entry-card[data-type="EVENT"] {
  border-left-color: var(--event);
}

.entry-card[data-type="REMINDER"] {
  border-left-color: var(--reminder);
}

.entry-card[data-type="OTHER"] {
  border-left-color: var(--other);
}

.entry-type {
  display: inline-block;
  font-size: 0.625rem;
  font-weight: 600;
  text-transform: uppercase;
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
  margin-bottom: 0.25rem;
  letter-spacing: 0.05em;
}

.entry-type[data-type="HOMEWORK"] {
  background-color: var(--homework);
  color: white;
}

.entry-type[data-type="EXAM"] {
  background-color: var(--exam);
  color: white;
}

.entry-type[data-type="EVENT"] {
  background-color: var(--event);
  color: white;
}

.entry-type[data-type="REMINDER"] {
  background-color: var(--reminder);
  color: white;
}

.entry-type[data-type="OTHER"] {
  background-color: var(--other);
  color: white;
}

.entry-title {
  font-weight: 600;
  font-size: 0.875rem;
  margin-bottom: 0.25rem;
  color: var(--text-primary);
}

.entry-description {
  font-size: 0.75rem;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
  line-height: 1.4;
}

.entry-meta {
  font-size: 0.625rem;
  color: var(--text-tertiary);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

/* Modal */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0, 0, 0, 0.5);
  z-index: 1000;
  overflow-y: auto;
  padding: 1rem;
}

.modal.active {
  display: flex;
  align-items: center;
  justify-content: center;
}

.modal-content {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  box-shadow: 0 10px 25px var(--shadow-lg);
  width: 100%;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
}

.modal-header {
  padding: 1.5rem;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-title {
  font-size: 1.25rem;
  font-weight: 700;
}

.modal-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--text-secondary);
  padding: 0;
  width: 2rem;
  height: 2rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.25rem;
}

.modal-close:hover {
  background-color: var(--bg-secondary);
  color: var(--text-primary);
}

.modal-body {
  padding: 1.5rem;
}

.modal-footer {
  padding: 1rem 1.5rem;
  border-top: 1px solid var(--border-color);
  display: flex;
  justify-content: flex-end;
  gap: 0.5rem;
}

/* Select dropdowns */
select.form-input {
  cursor: pointer;
}

/* Textarea */
textarea.form-input {
  resize: vertical;
  min-height: 80px;
}

/* Loading spinner */
.spinner {
  border: 3px solid var(--bg-tertiary);
  border-top-color: var(--primary);
  border-radius: 50%;
  width: 2rem;
  height: 2rem;
  animation: spin 0.8s linear infinite;
  margin: 2rem auto;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* Utilities */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }

/* User info badge */
.user-info {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem 0.75rem;
  background-color: var(--bg-secondary);
  border-radius: 0.375rem;
  font-size: 0.875rem;
}

.user-role {
  font-size: 0.75rem;
  padding: 0.125rem 0.375rem;
  border-radius: 0.25rem;
  background-color: var(--primary-light);
  color: var(--primary);
  font-weight: 600;
}

/* Admin Panel */
.admin-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 1rem;
}

.admin-section {
  background-color: var(--bg-primary);
  border-radius: 0.5rem;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
  box-shadow: 0 1px 3px var(--shadow);
}

.admin-section-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 1rem;
  color: var(--text-primary);
}

/* Table */
.table-container {
  overflow-x: auto;
  margin-top: 1rem;
}

table {
  width: 100%;
  border-collapse: collapse;
}

thead {
  background-color: var(--bg-secondary);
}

th {
  padding: 0.75rem;
  text-align: left;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

td {
  padding: 0.75rem;
  border-top: 1px solid var(--border-color);
  font-size: 0.875rem;
}

tr:hover {
  background-color: var(--bg-secondary);
}

.table-actions {
  display: flex;
  gap: 0.5rem;
}

/* Responsive adjustments */
@media (max-width: 640px) {
  .app-title {
    font-size: 1.25rem;
  }

  .header-actions {
    width: 100%;
    justify-content: space-between;
  }

  .week-nav-controls {
    flex-direction: column;
  }

  .week-info {
    order: -1;
  }

  table {
    font-size: 0.75rem;
  }

  th, td {
    padding: 0.5rem;
  }
}

/* Empty state */
.empty-state {
  text-align: center;
  padding: 3rem 1rem;
  color: var(--text-secondary);
}

.empty-state-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
  opacity: 0.5;
}

.empty-state-text {
  font-size: 1rem;
  margin-bottom: 0.5rem;
}

.empty-state-subtext {
  font-size: 0.875rem;
  color: var(--text-tertiary);
}