/* Reusable UI Components System — ProblemX */

/* 1. BUTTON SYSTEM */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font-secondary);
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-semibold);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-btn);
  border: 2px solid transparent;
  transition: all 0.2s ease;
  user-select: none;
  cursor: pointer;
  white-space: nowrap;
}

.btn:active {
  transform: scale(0.97);
}

.btn:disabled {
  background-color: var(--color-disabled);
  color: var(--color-disabled-text);
  border-color: transparent;
  cursor: not-allowed;
  transform: none;
}

/* Button Variants */
.btn-primary {
  background-color: var(--color-primary);
  color: #FFFFFF;
}
.btn-primary:hover:not(:disabled) {
  background-color: var(--color-primary-hover);
  box-shadow: 0 0 12px rgba(37, 99, 235, 0.4);
}

.btn-secondary {
  background-color: transparent;
  border-color: var(--color-primary);
  color: var(--color-primary);
}
.btn-secondary:hover:not(:disabled) {
  background-color: var(--color-primary-light);
}

.btn-ghost {
  background-color: transparent;
  color: var(--color-text-secondary);
}
.btn-ghost:hover:not(:disabled) {
  background-color: var(--color-bg-secondary);
  color: var(--color-text-primary);
}

.btn-danger {
  background-color: var(--color-danger);
  color: #FFFFFF;
}
.btn-danger:hover:not(:disabled) {
  background-color: var(--color-danger-hover);
  box-shadow: 0 0 12px rgba(239, 68, 68, 0.4);
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--fs-caption);
  border-radius: var(--radius-sm);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--fs-body-md);
}


/* 2. INPUT COMPONENTS */
.form-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
  width: 100%;
}

.form-label {
  font-size: var(--fs-body-sm);
  font-weight: var(--fw-semibold);
  color: var(--color-text-primary);
}

.input-field {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  font-size: var(--fs-body-sm);
  color: var(--color-text-primary);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease;
}

/* Input States */
.input-field:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px var(--color-primary-light);
  outline: none;
}

.input-field.input-error {
  border-color: var(--color-danger);
}
.input-field.input-error:focus {
  box-shadow: 0 0 0 3px var(--color-danger-light);
}

.input-field.input-success {
  border-color: var(--color-success);
}
.input-field.input-success:focus {
  box-shadow: 0 0 0 3px var(--color-success-light);
}

.input-field:disabled {
  background-color: var(--color-bg-secondary);
  color: var(--color-disabled-text);
  cursor: not-allowed;
  box-shadow: none;
}

/* Helper text below input */
.input-helper {
  font-size: var(--fs-caption);
  color: var(--color-text-secondary);
}
.input-error-text {
  font-size: var(--fs-caption);
  color: var(--color-danger);
}


/* 3. MODAL SCREEN */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background-color: rgba(15, 23, 42, 0.6);
  backdrop-filter: blur(4px);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.modal-backdrop.show {
  opacity: 1;
  pointer-events: auto;
}

.modal-container {
  background-color: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  width: 100%;
  max-width: 520px;
  overflow: hidden;
  transform: translateY(20px);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), background-color 0.3s ease;
}

.modal-backdrop.show .modal-container {
  transform: translateY(0);
}

.modal-header {
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.modal-title {
  font-family: var(--font-secondary);
  font-size: var(--fs-h4);
  font-weight: var(--fw-bold);
  color: var(--color-text-primary);
}

.modal-close-btn {
  color: var(--color-text-secondary);
  font-size: 20px;
  cursor: pointer;
  transition: color 0.2s ease;
}
.modal-close-btn:hover {
  color: var(--color-text-primary);
}

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

.modal-footer {
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: flex-end;
  gap: var(--space-3);
  background-color: var(--color-bg-secondary);
}


/* 4. TOAST SYSTEM */
.toast-container {
  position: fixed;
  top: 24px;
  right: 24px;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  z-index: 2000;
  max-width: 360px;
  width: 100%;
}

.toast {
  background-color: var(--color-card);
  color: var(--color-text-primary);
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-lg);
  padding: var(--space-4);
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  animation: toastFadeIn 0.3s cubic-bezier(0.16, 1, 0.3, 1) forwards;
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.toast.toast-success { border-left-color: var(--color-success); }
.toast.toast-danger { border-left-color: var(--color-danger); }
.toast.toast-warning { border-left-color: var(--color-warning); }
.toast.toast-info { border-left-color: var(--color-primary); }

.toast-icon {
  flex-shrink: 0;
  margin-top: 2px;
}
.toast.toast-success .toast-icon { color: var(--color-success); }
.toast.toast-danger .toast-icon { color: var(--color-danger); }
.toast.toast-warning .toast-icon { color: var(--color-warning); }
.toast.toast-info .toast-icon { color: var(--color-primary); }

.toast-content {
  flex-grow: 1;
  font-size: var(--fs-body-sm);
}

.toast-title {
  font-weight: var(--fw-semibold);
  margin-bottom: var(--space-1);
}

.toast-close {
  color: var(--color-text-secondary);
  cursor: pointer;
  flex-shrink: 0;
  font-size: 16px;
}
.toast-close:hover {
  color: var(--color-text-primary);
}

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

/* 5. BADGES, TAGS, AVATARS */
.tag-pill {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--fs-caption);
  font-weight: var(--fw-medium);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border);
  color: var(--color-text-secondary);
}

.tag-pill.tag-easy { background-color: var(--color-success-light); border-color: var(--color-success-border); color: var(--color-success); }
.tag-pill.tag-medium { background-color: var(--color-warning-light); border-color: var(--color-warning-border); color: var(--color-warning); }
.tag-pill.tag-hard { background-color: var(--color-danger-light); border-color: var(--color-danger-border); color: var(--color-danger); }

/* Loading Spinner */
.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid var(--color-border);
  border-top-color: var(--color-primary);
  border-radius: var(--radius-full);
  animation: spin 0.8s linear infinite;
}

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

/* Responsive toast adjustments */
@media (max-width: 480px) {
  .toast-container {
    top: auto;
    bottom: 24px;
    right: 24px;
    left: 24px;
    max-width: none;
    width: auto;
  }
}