/* ============================================================
   Rail Design System — Dialog
   Heard · Guest + Line

   Variants: standard, confirmation-neutral, confirmation-destructive
   Backdrop: neutral-950 at 40% opacity
   Container: surface-raised, radius-md, elevation-3

   Usage:
   <!--
     Standard dialog:
     <div class="rail-dialog-backdrop" aria-hidden="true"></div>
     <dialog class="rail-dialog" role="dialog" aria-labelledby="dialog-title" aria-modal="true" open>
       <div class="rail-dialog__header">
         <h2 class="rail-dialog__title" id="dialog-title">Edit menu item</h2>
         <button class="rail-dialog__close" aria-label="Close dialog">
           <svg aria-hidden="true" width="20" height="20">...</svg>
         </button>
       </div>
       <div class="rail-dialog__body">
         <p>Dialog content goes here.</p>
       </div>
       <div class="rail-dialog__footer">
         <button class="rail-dialog__btn rail-dialog__btn--secondary">Cancel</button>
         <button class="rail-dialog__btn rail-dialog__btn--primary">Save</button>
       </div>
     </dialog>

     Confirmation dialog (neutral):
     <dialog class="rail-dialog rail-dialog--confirmation" ...>
       <div class="rail-dialog__body">
         <h2 class="rail-dialog__title" id="dialog-title">Confirm changes?</h2>
         <p>This will update the menu for all locations.</p>
       </div>
       <div class="rail-dialog__footer">
         <button class="rail-dialog__btn rail-dialog__btn--secondary">Cancel</button>
         <button class="rail-dialog__btn rail-dialog__btn--primary">Confirm</button>
       </div>
     </dialog>

     Confirmation dialog (destructive):
     <dialog class="rail-dialog rail-dialog--confirmation" ...>
       <div class="rail-dialog__body">
         <h2 class="rail-dialog__title" id="dialog-title">Delete this item?</h2>
         <p>This action cannot be undone.</p>
       </div>
       <div class="rail-dialog__footer">
         <button class="rail-dialog__btn rail-dialog__btn--secondary">Cancel</button>
         <button class="rail-dialog__btn rail-dialog__btn--destructive">Delete</button>
       </div>
     </dialog>
   -->
   ============================================================ */


/* --- Backdrop --- */

.rail-dialog-backdrop {
  position: fixed;
  inset: 0;
  background-color: color-mix(in srgb, var(--surface-overlay) 45%, transparent); /* neutral-950 at 40% */
  z-index: 999;
  animation: rail-dialog-fade-in 200ms ease;
}


/* --- Dialog container --- */

/* A closed <dialog> must not render. display:flex below would beat the UA
   rule, so state it explicitly. */
.rail-dialog:not([open]) {
  display: none;
}

.rail-dialog {
  position: fixed;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 1000;
  display: flex;
  flex-direction: column;
  width: calc(100% - 2 * var(--space-inset-lg));
  max-width: 480px;
  max-height: calc(100vh - 2 * var(--space-inset-lg));
  margin: 0;
  padding: 0;
  background-color: var(--surface-raised);
  border: 1px solid var(--border-default);
  border-radius: var(--radius-md);
  box-shadow: var(--elevation-3);
  box-sizing: border-box;
  overflow: hidden;
  animation: rail-dialog-slide-in 250ms ease;
}


/* --- Header --- */

.rail-dialog__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-inset-md) var(--dialog-body-padding);
  border-bottom: 1px solid var(--border-subtle);
  flex-shrink: 0;
}

.rail-dialog__title {
  margin: 0;
  font-family: 'DM Sans', sans-serif;
  font-size: var(--type-heading-size);
  line-height: var(--type-heading-line);
  font-weight: var(--type-heading-weight);
  color: var(--text-primary);
}


/* --- Close button --- */

.rail-dialog__close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--target-min);
  height: var(--target-min);
  padding: 0;
  border: none;
  border-radius: var(--radius-sm);
  background: transparent;
  color: var(--text-tertiary);
  cursor: pointer;
  transition: background-color 150ms ease, color 150ms ease;
  flex-shrink: 0;
}

.rail-dialog__close:hover {
  background-color: var(--surface-subtle);
  color: var(--text-primary);
}

.rail-dialog__close:focus-visible {
  outline: var(--focus-ring-width) solid var(--border-focus);
  outline-offset: var(--focus-ring-offset);
}


/* --- Body --- */

.rail-dialog__body {
  padding: var(--dialog-body-padding);
  overflow-y: auto;
  flex: 1;
  font-family: 'Inter', sans-serif;
  font-size: var(--type-body-size);
  line-height: var(--type-body-line);
  color: var(--text-secondary);
}

.rail-dialog__body p {
  margin: 0 0 var(--space-stack-sm);
}

.rail-dialog__body p:last-child {
  margin-bottom: 0;
}


/* --- Confirmation variant: title inside body --- */

.rail-dialog--confirmation .rail-dialog__body .rail-dialog__title {
  font-family: 'DM Sans', sans-serif;
  font-size: var(--type-heading-size);
  line-height: var(--type-heading-line);
  font-weight: var(--type-heading-weight);
  color: var(--text-primary);
  margin: 0 0 var(--space-stack-sm);
}


/* --- Footer --- */

.rail-dialog__footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--space-gap-sm);
  padding: var(--space-inset-md) var(--dialog-body-padding);
  border-top: 1px solid var(--border-subtle);
  flex-shrink: 0;
}


/* --- Footer buttons --- */

.rail-dialog__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: var(--target-min);
  padding: 0 var(--space-inset-md);
  font-family: 'Inter', sans-serif;
  font-size: var(--type-label-size);
  line-height: var(--type-label-line);
  font-weight: var(--type-label-weight);
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color 150ms ease;
  box-sizing: border-box;
}

.rail-dialog__btn:focus-visible {
  outline: var(--focus-ring-width) solid var(--border-focus);
  outline-offset: var(--focus-ring-offset);
}

/* Primary action */
.rail-dialog__btn--primary {
  background-color: var(--interactive-default);
  color: var(--text-on-brand);
}

.rail-dialog__btn--primary:hover {
  background-color: var(--interactive-hover);
}

.rail-dialog__btn--primary:active {
  background-color: var(--interactive-pressed);
}

/* Secondary action */
.rail-dialog__btn--secondary {
  background-color: transparent;
  color: var(--text-secondary);
}

.rail-dialog__btn--secondary:hover {
  background-color: var(--surface-subtle);
}

/* Destructive action */
.rail-dialog__btn--destructive {
  background-color: var(--feedback-error);
  color: var(--text-on-brand);
}

.rail-dialog__btn--destructive:hover {
  opacity: 0.9;
}


/* --- Animations --- */

@keyframes rail-dialog-fade-in {
  from { opacity: 0; }
  to   { opacity: 1; }
}

@keyframes rail-dialog-slide-in {
  from {
    opacity: 0;
    transform: translate(-50%, -48%);
  }
  to {
    opacity: 1;
    transform: translate(-50%, -50%);
  }
}


/* --- Responsive: full-width on small screens --- */

@media (max-width: 480px) {
  .rail-dialog {
    width: calc(100% - 2 * var(--space-inset-md));
    max-width: none;
  }
}