/**
 * GCSE Revision Hub - Modal System Styles
 *
 * Feature: F-032.3 Modal System with Queue Management
 * Version: 1.0
 * Created: 2026-01-20
 *
 * Professional modal styling with glassmorphism containers and solid backdrops.
 *
 * DEPENDENCIES:
 * - css/design-system.css (design tokens)
 * - css/components-v2.css (component library)
 *
 * CRITICAL DESIGN RULES:
 * - Backdrop: SOLID 85% opacity (NO blur effect)
 * - Modal container: Glassmorphism (70% opacity + 10px blur)
 * - Toast: Glassmorphism (70% opacity + 10px blur)
 */

/* ============================================================================
   MODAL
   ============================================================================ */

/* --------------------------------------------------------------------------
   Modal Base
   -------------------------------------------------------------------------- */

.modal {
  position: fixed;
  inset: 0;
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--duration-normal) var(--ease-in-out),
              visibility var(--duration-normal) var(--ease-in-out);
}

.modal--active {
  opacity: 1;
  visibility: visible;
}

/* --------------------------------------------------------------------------
   Modal Backdrop (SOLID - NO BLUR)
   -------------------------------------------------------------------------- */

.modal__backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.85); /* SOLID 85% opacity */
  z-index: -1;
  /* NO backdrop-filter - backdrop stays solid */
}

/* --------------------------------------------------------------------------
   Modal Container (GLASSMORPHISM)
   -------------------------------------------------------------------------- */

.modal__container {
  position: relative;
  width: 90vw;
  max-width: 500px;
  max-height: 90vh;
  overflow-y: auto;
  background: var(--glass-bg); /* 70% opacity */
  backdrop-filter: blur(var(--glass-blur)); /* 10px blur */
  -webkit-backdrop-filter: blur(var(--glass-blur)); /* Safari support */
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  transform: scale(0.9);
  transition: transform var(--duration-normal) var(--ease-out);
}

.modal--active .modal__container {
  transform: scale(1);
}

/* --------------------------------------------------------------------------
   Modal Header
   -------------------------------------------------------------------------- */

.modal__header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-6);
  border-bottom: 1px solid var(--glass-border);
}

.modal__title {
  font-size: var(--text-2xl);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin: 0;
  line-height: var(--leading-tight);
}

.modal__close {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition-colors);
}

.modal__close:hover {
  background: var(--bg-interactive);
  color: var(--text-primary);
}

.modal__close:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.modal__close svg {
  width: 20px;
  height: 20px;
}

/* --------------------------------------------------------------------------
   Modal Body
   -------------------------------------------------------------------------- */

.modal__body {
  padding: var(--space-6);
  color: var(--text-secondary);
  line-height: var(--leading-relaxed);
}

.modal__body > *:first-child {
  margin-top: 0;
}

.modal__body > *:last-child {
  margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   Modal Footer
   -------------------------------------------------------------------------- */

.modal__footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-3);
  padding: var(--space-6);
  border-top: 1px solid var(--glass-border);
}

/* --------------------------------------------------------------------------
   Modal Variants
   -------------------------------------------------------------------------- */

/* Success Modal */
.modal--success .modal__header {
  border-bottom-color: var(--color-success);
}

.modal--success .modal__title {
  color: var(--color-success);
}

/* Error Modal */
.modal--error .modal__header {
  border-bottom-color: var(--color-error);
}

.modal--error .modal__title {
  color: var(--color-error);
}

/* Warning Modal */
.modal--warning .modal__header {
  border-bottom-color: var(--color-warning);
}

.modal--warning .modal__title {
  color: var(--color-warning);
}

/* Info Modal */
.modal--info .modal__header {
  border-bottom-color: var(--color-primary);
}

.modal--info .modal__title {
  color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   Modal Sizes
   -------------------------------------------------------------------------- */

.modal--sm .modal__container {
  max-width: 400px;
}

.modal--md .modal__container {
  max-width: 500px; /* Default */
}

.modal--lg .modal__container {
  max-width: 700px;
}

.modal--xl .modal__container {
  max-width: 900px;
}

.modal--full .modal__container {
  width: 95vw;
  max-width: none;
  max-height: 95vh;
}

/* ============================================================================
   TOAST NOTIFICATIONS
   ============================================================================ */

/* --------------------------------------------------------------------------
   Toast Container
   -------------------------------------------------------------------------- */

.toast-container {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  z-index: 10001; /* Above modals */
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  max-width: 450px;
  pointer-events: none;
}

/* --------------------------------------------------------------------------
   Toast Base
   -------------------------------------------------------------------------- */

.toast {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-4);
  background: var(--glass-bg); /* 70% opacity */
  backdrop-filter: blur(var(--glass-blur)); /* 10px blur */
  -webkit-backdrop-filter: blur(var(--glass-blur)); /* Safari support */
  border: 1px solid var(--glass-border);
  border-left-width: 4px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  pointer-events: auto;
  transform: translateY(20px);
  opacity: 0;
  transition: transform var(--duration-normal) var(--ease-out),
              opacity var(--duration-normal) var(--ease-out);
}

.toast--active {
  transform: translateY(0);
  opacity: 1;
}

/* --------------------------------------------------------------------------
   Toast Icon
   -------------------------------------------------------------------------- */

.toast__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  display: flex;
  align-items: center;
  justify-content: center;
}

/* --------------------------------------------------------------------------
   Toast Content
   -------------------------------------------------------------------------- */

.toast__content {
  flex: 1;
  min-width: 0;
}

.toast__title {
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  color: var(--text-primary);
  margin: 0 0 var(--space-1) 0;
}

.toast__description {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  line-height: var(--leading-normal);
}

/* --------------------------------------------------------------------------
   Toast Action Button
   -------------------------------------------------------------------------- */

.toast__action {
  flex-shrink: 0;
  padding: var(--space-1) var(--space-3);
  background: transparent;
  border: 1px solid var(--border-default);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  cursor: pointer;
  transition: var(--transition-colors);
}

.toast__action:hover {
  background: var(--bg-interactive);
  border-color: var(--border-strong);
}

.toast__action:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Toast Close Button
   -------------------------------------------------------------------------- */

.toast__close {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition-colors);
}

.toast__close:hover {
  background: var(--bg-interactive);
  color: var(--text-primary);
}

.toast__close:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.toast__close svg {
  width: 14px;
  height: 14px;
}

/* --------------------------------------------------------------------------
   Toast Types (Border Colors)
   -------------------------------------------------------------------------- */

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

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

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

.toast--error .toast__icon {
  color: var(--color-error);
}

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

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

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

.toast--info .toast__icon {
  color: var(--color-primary);
}

/* ============================================================================
   RESPONSIVE DESIGN
   ============================================================================ */

/* Mobile */
@media (max-width: 640px) {
  .modal {
    padding: var(--space-2);
  }

  .modal__container {
    width: 100%;
    max-width: none;
    border-radius: var(--radius-xl);
  }

  .modal__header,
  .modal__body,
  .modal__footer {
    padding: var(--space-5);
  }

  .modal__title {
    font-size: var(--text-xl);
  }

  .modal__footer {
    flex-direction: column;
    align-items: stretch;
  }

  .modal__footer .btn {
    width: 100%;
  }

  .toast-container {
    bottom: var(--space-4);
    right: var(--space-4);
    left: var(--space-4);
    max-width: none;
  }

  .toast {
    width: 100%;
  }
}

/* Tablet */
@media (min-width: 641px) and (max-width: 1024px) {
  .modal__container {
    max-width: 600px;
  }
}

/* ============================================================================
   ACCESSIBILITY: REDUCED MOTION SUPPORT
   ============================================================================ */

@media (prefers-reduced-motion: reduce) {
  .modal,
  .modal__container,
  .toast {
    transition: none;
  }

  .modal--active {
    opacity: 1;
  }

  .modal--active .modal__container {
    transform: scale(1);
  }

  .toast--active {
    transform: translateY(0);
    opacity: 1;
  }
}

/* ============================================================================
   MOBILE OPTIMIZATIONS
   ============================================================================ */

/* Ensure modals fit on small screens */
@media (max-width: 320px) {
  .modal {
    padding: var(--space-1);
  }

  .modal__header,
  .modal__body,
  .modal__footer {
    padding: var(--space-4);
  }

  .toast-container {
    bottom: var(--space-3);
    right: var(--space-3);
    left: var(--space-3);
  }
}

/* Touch device optimizations */
@media (hover: none) and (pointer: coarse) {
  .modal__close,
  .toast__close {
    min-width: 44px; /* WCAG touch target */
    min-height: 44px;
  }

  .toast__action {
    min-height: 36px;
    padding: var(--space-2) var(--space-4);
  }
}

/* ============================================================================
   GLASSMORPHISM FALLBACK
   ============================================================================ */

/**
 * For browsers that don't support backdrop-filter (< 5% of users),
 * increase opacity for better readability without the blur effect.
 */
@supports not (backdrop-filter: blur(10px)) {
  .modal__container,
  .toast {
    background: rgba(30, 41, 59, 0.95); /* Dark mode fallback */
  }

  [data-theme="light"] .modal__container,
  [data-theme="light"] .toast {
    background: rgba(255, 255, 255, 0.95); /* Light mode fallback */
  }
}