/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-2);
  padding: var(--spacing-3) var(--spacing-5);
  font-size: var(--text-sm);
  font-weight: 500;
  line-height: 1.5;
  border-radius: var(--radius);
  border: 1px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

.btn-sm {
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--text-xs);
}

.btn-lg {
  padding: var(--spacing-4) var(--spacing-6);
  font-size: var(--text-base);
}

.btn-block {
  width: 100%;
}

/* Button Variants */
.btn-primary {
  background-color: var(--primary);
  color: white;
}

.btn-primary:hover:not(:disabled) {
  background-color: var(--primary-dark);
  transform: translateY(-1px);
}

.btn-ai {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  border: none;
}

.btn-ai:hover:not(:disabled) {
  background: linear-gradient(135deg, #5a6fd6 0%, #6a4190 100%);
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary:hover:not(:disabled) {
  opacity: 0.9;
  transform: translateY(-1px);
}

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

.btn-success:hover:not(:disabled) {
  opacity: 0.9;
  transform: translateY(-1px);
}

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

.btn-danger:hover:not(:disabled) {
  opacity: 0.9;
  transform: translateY(-1px);
}

.btn-outline {
  background-color: transparent;
  border-color: var(--border-color);
  color: var(--text-primary);
}

.btn-outline:hover:not(:disabled) {
  background-color: var(--bg-hover);
  border-color: var(--text-muted);
}

.btn-ghost {
  background-color: #f01b1b;
  color: #fff;
}

.btn-ghost:hover:not(:disabled) {
  background-color: #d61717;
}

@media (max-width: 768px) {
  .btn {
    min-height: 44px;
  }

  .btn.icon-only-mobile {
    width: 44px;
    min-width: 44px;
    padding: 0;
    gap: 0;
    justify-content: center;
    border-radius: 50%;
  }

  .btn.icon-only-mobile .btn-text {
    display: none;
  }

  .btn.icon-only-mobile svg,
  .btn.icon-only-mobile i {
    width: 18px;
    height: 18px;
    font-size: 18px;
    line-height: 1;
  }

  .btn-sm.btn-icon-only-mobile {
    width: 40px;
    min-width: 40px;
    height: 40px;
    min-height: 40px;
  }

  .btn-sm.btn-icon-only-mobile svg {
    width: 16px;
    height: 16px;
  }
}

/* Card */
.card {
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: var(--spacing-6);
  border: 1px solid var(--gray-200);
}

.class-card {
  border-left: 4px solid var(--primary);
  box-shadow: var(--shadow-md);
}

.class-card .card-header h3 {
  color: var(--gray-900);
}

.card-header {
  margin-bottom: var(--spacing-4);
  padding-bottom: var(--spacing-4);
  border-bottom: 1px solid var(--gray-200);
}

.card-header h3 {
  font-size: var(--text-lg);
  color: var(--gray-900);
}

.card-title {
  font-size: var(--text-xl);
  font-weight: 600;
  color: var(--gray-900);
  margin-bottom: var(--spacing-2);
}

.card-body {
  margin-bottom: var(--spacing-4);
}

.card-footer {
  padding-top: var(--spacing-4);
  border-top: 1px solid var(--gray-200);
  display: flex;
  gap: var(--spacing-3);
  justify-content: flex-end;
}

/* Form Elements */
.form-group {
  margin-bottom: var(--spacing-5);
}

.form-group label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--gray-700);
  margin-bottom: var(--spacing-2);
}

.form-group label .required {
  color: var(--danger);
  margin-left: 2px;
}

.form-group .help-text {
  font-size: var(--text-xs);
  color: var(--gray-500);
  margin-top: var(--spacing-1);
}

.input,
.select,
.textarea {
  width: 100%;
  padding: var(--spacing-3);
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--gray-900);
  background-color: white;
  border: 1px solid var(--gray-300);
  border-radius: var(--radius);
  transition: all var(--transition-fast);
}

.input:focus,
.select:focus,
.textarea:focus {
  outline: none;
  border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.input:disabled,
.select:disabled,
.textarea:disabled {
  background-color: var(--gray-100);
  cursor: not-allowed;
}

.textarea {
  resize: vertical;
  min-height: 100px;
}

.select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 20 20'%3e%3cpath stroke='%236b7280' stroke-linecap='round' stroke-linejoin='round' stroke-width='1.5' d='M6 8l4 4 4-4'/%3e%3c/svg%3e");
  background-position: right 0.5rem center;
  background-repeat: no-repeat;
  background-size: 1.5em 1.5em;
  padding-right: 2.5rem;
}

/* Checkbox & Radio */
.checkbox,
.radio {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  cursor: pointer;
}

.checkbox input[type="checkbox"],
.radio input[type="radio"] {
  width: 1.25rem;
  height: 1.25rem;
  cursor: pointer;
  accent-color: var(--primary);
}

.checkbox label,
.radio label {
  margin: 0;
  cursor: pointer;
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--spacing-1) var(--spacing-3);
  font-size: var(--text-xs);
  font-weight: 500;
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.badge-primary {
  background-color: #dbeafe;
  color: #1e40af;
}

.badge-secondary {
  background-color: #ede9fe;
  color: #5b21b6;
}

.badge-success {
  background-color: #d1fae5;
  color: #065f46;
}

.badge-warning {
  background-color: #fef3c7;
  color: #92400e;
}

.badge-danger {
  background-color: #fee2e2;
  color: #991b1b;
}

.badge-info {
  background-color: #cffafe;
  color: #0e7490;
}

.badge-gray {
  background-color: var(--gray-100);
  color: var(--gray-700);
}

/* Alert */
.alert {
  padding: var(--spacing-4);
  border-radius: var(--radius);
  margin-bottom: var(--spacing-4);
  display: flex;
  align-items: flex-start;
  gap: var(--spacing-3);
  border: 1px solid transparent;
}

.alert-icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

.alert-content {
  flex: 1;
}

.alert-title {
  font-weight: 600;
  margin-bottom: var(--spacing-1);
}

.alert-message {
  font-size: var(--text-sm);
}

.alert-success {
  background-color: #f0fdf4;
  border-color: #bbf7d0;
  color: #166534;
}

.alert-warning {
  background-color: #fffbeb;
  border-color: #fde68a;
  color: #92400e;
}

.alert-danger {
  background-color: #fef2f2;
  border-color: #fecaca;
  color: #991b1b;
}

.alert-info {
  background-color: #ecfeff;
  border-color: #a5f3fc;
  color: #155e75;
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: var(--z-modal);
  display: none;
  align-items: center;
  justify-content: center;
  padding: var(--spacing-4);
}

.modal.active {
  display: flex;
}

.modal-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(2px);
}

.modal-content {
  position: relative;
  background: white;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  max-width: 600px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  animation: modalSlideIn 0.3s ease-out;
}

@keyframes modalSlideIn {
  from {
    opacity: 0;
    transform: translateY(-20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-6);
  border-bottom: 1px solid var(--gray-200);
}

.modal-title {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--gray-900);
}

.modal-close {
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius);
  color: var(--gray-500);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.modal-close:hover {
  background-color: var(--gray-100);
  color: var(--gray-700);
}

.modal-body {
  padding: var(--spacing-6);
}

.modal-footer {
  display: flex;
  gap: var(--spacing-3);
  justify-content: flex-end;
  padding: var(--spacing-6);
  border-top: 1px solid var(--gray-200);
}

/* Dropdown */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropdown-menu {
  position: absolute;
  top: 100%;
  left: 0;
  z-index: var(--z-dropdown);
  min-width: 180px;
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border: 1px solid var(--gray-200);
  padding: var(--spacing-2);
  margin-top: var(--spacing-2);
  display: none;
  animation: dropdownFadeIn 0.2s ease-out;
}

.dropdown.active .dropdown-menu {
  display: block;
}

@keyframes dropdownFadeIn {
  from {
    opacity: 0;
    transform: translateY(-10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.dropdown-item {
  display: flex;
  align-items: center;
  gap: var(--spacing-2);
  padding: var(--spacing-2) var(--spacing-3);
  font-size: var(--text-sm);
  color: var(--gray-700);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.dropdown-item:hover {
  background-color: var(--gray-100);
}

.dropdown-divider {
  height: 1px;
  background-color: var(--gray-200);
  margin: var(--spacing-2) 0;
}

/* Tabs */
.tabs {
  border-bottom: 1px solid var(--gray-200);
}

.tabs-list {
  display: flex;
  gap: var(--spacing-1);
}

.tab-item {
  padding: var(--spacing-3) var(--spacing-5);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--gray-500);
  border-bottom: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tab-item:hover {
  color: var(--gray-700);
}

.tab-item.active {
  color: var(--primary);
  border-bottom-color: var(--primary);
}

.tab-content {
  padding-top: var(--spacing-6);
}

.tab-panel {
  display: none;
}

.tab-panel.active {
  display: block;
}

/* Table */
.table-container {
  overflow-x: auto;
  border-radius: var(--radius);
  border: 1px solid var(--gray-200);
}

.table {
  width: 100%;
  border-collapse: collapse;
  background: white;
}

.table thead {
  background-color: var(--gray-50);
  border-bottom: 1px solid var(--gray-200);
}

.table th {
  padding: var(--spacing-3) var(--spacing-4);
  text-align: left;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--gray-600);
}

.table td {
  padding: var(--spacing-3) var(--spacing-4);
  font-size: var(--text-sm);
  color: var(--gray-900);
  border-bottom: 1px solid var(--gray-200);
}

.table tbody tr:last-child td {
  border-bottom: none;
}

.table tbody tr:hover {
  background-color: var(--gray-50);
}

/* Loading */
.loading {
  display: inline-block;
  width: 20px;
  height: 20px;
  border: 2px solid var(--gray-300);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.6s linear infinite;
}

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

/* Toast */
.toast-container {
  position: fixed;
  top: var(--spacing-4);
  right: var(--spacing-4);
  z-index: var(--z-tooltip);
  display: flex;
  flex-direction: column;
  gap: var(--spacing-3);
  pointer-events: none;
}

.toast {
  pointer-events: auto;
  min-width: 300px;
  padding: var(--spacing-4);
  background: white;
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  border-left: 4px solid var(--primary);
  animation: toastSlideIn 0.3s ease-out;
}

@keyframes toastSlideIn {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

.toast-success {
  border-left-color: var(--success);
}

.toast-error {
  border-left-color: var(--danger);
}

.toast-warning {
  border-left-color: var(--warning);
}

.toast-info {
  border-left-color: var(--info);
}

/* Utilities */
.text-center {
  text-align: center;
}

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

.text-muted {
  color: var(--gray-500);
}

.mt-0 {
  margin-top: 0;
}

.mt-1 {
  margin-top: var(--spacing-1);
}

.mt-2 {
  margin-top: var(--spacing-2);
}

.mt-3 {
  margin-top: var(--spacing-3);
}

.mt-4 {
  margin-top: var(--spacing-4);
}

.mt-6 {
  margin-top: var(--spacing-6);
}

.mb-0 {
  margin-bottom: 0;
}

.mb-1 {
  margin-bottom: var(--spacing-1);
}

.mb-2 {
  margin-bottom: var(--spacing-2);
}

.mb-3 {
  margin-bottom: var(--spacing-3);
}

.mb-4 {
  margin-bottom: var(--spacing-4);
}

.mb-6 {
  margin-bottom: var(--spacing-6);
}

.d-none {
  display: none;
}

.d-flex {
  display: flex;
}

.d-block {
  display: block;
}

.w-full {
  width: 100%;
}

.h-full {
  height: 100%;
}