/* ==========================================================================
   app.css — Application UI (chrome, editor, controls)
   Mobile-first. Desktop split layout is layered on at the md breakpoint.
   Preview *content* styling lives in preview.css.
   ========================================================================== */

/* ---- App shell: header / workspace / footer stacked to fill viewport ---- */
body {
  display: flex;
  flex-direction: column;
}

/* ==========================================================================
   Header
   ========================================================================== */
.app-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  height: var(--header-height);
  padding: 0 var(--space-4);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.brand {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-lg);
  font-weight: 650;
  letter-spacing: -0.01em;
}

.brand__mark {
  color: var(--color-accent);
  font-size: 1.15em;
}

.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: border-color var(--transition-fast),
    background-color var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

.theme-toggle__icon {
  width: 1rem;
  height: 1rem;
  border-radius: var(--radius-full);
  border: 2px solid currentColor;
  /* Simple sun/moon cue via a half-filled dot; refined in the theme phase. */
  background: linear-gradient(90deg, currentColor 50%, transparent 50%);
}

/* ==========================================================================
   Mobile view toggle (segmented control) — hidden on desktop
   ========================================================================== */
.view-toggle {
  display: flex;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.view-toggle__tab {
  flex: 1;
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  font-weight: 550;
  cursor: pointer;
  transition: background-color var(--transition-fast),
    color var(--transition-fast);
}

.view-toggle__tab[aria-pressed="true"] {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-accent-contrast);
}

/* ==========================================================================
   Workspace split
   ========================================================================== */
.workspace {
  flex: 1;
  min-height: 0; /* allow children to scroll instead of growing the page */
  display: flex;
  flex-direction: column;
}

/* Both panes scroll independently and fill available height */
.editor,
.preview {
  min-height: 0;
  overflow-y: auto;
  background: var(--color-bg);
}

/* --- Mobile: show a single pane based on data-mobile-view --- */
@media (max-width: 47.99em) {
  .workspace:not([data-mobile-view="preview"]) .preview {
    display: none;
  }
  .workspace[data-mobile-view="preview"] .editor {
    display: none;
  }
  .editor,
  .preview {
    flex: 1;
  }
}

/* ==========================================================================
   Editor form
   ========================================================================== */
.editor__form {
  width: 100%;
  max-width: var(--editor-max);
  margin: 0 auto;
  padding: var(--space-5) var(--space-4) var(--space-7);
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

/* ---- Field ---- */
.field {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  border: 0;
  padding: 0;
}

.field__label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text);
}

.field__hint {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.field__input {
  width: 100%;
  padding: var(--space-2) var(--space-3);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  color: var(--color-text);
  transition: border-color var(--transition-fast),
    box-shadow var(--transition-fast);
}

.field__input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.7;
}

.field__input:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: var(--focus-ring);
}

.field__input--area {
  min-height: 4.5rem;
  line-height: var(--leading-normal);
}

.field__input--mono {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
}

.field__select {
  cursor: pointer;
  appearance: none;
  /* Chevron via inline SVG so no external asset is needed */
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 16 16' fill='none' stroke='%2359636e' stroke-width='1.5'%3E%3Cpath d='M4 6l4 4 4-4'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right var(--space-3) center;
  padding-right: var(--space-6);
}

/* ==========================================================================
   Tech-stack chips
   Contract for formManager output:
     fieldset.tech-stack__group
       legend.tech-stack__legend
       div.tech-stack__chips
         label.chip > input[type=checkbox].sr-only + span.chip__label
   ========================================================================== */
.tech-stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.tech-stack__group {
  border: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.tech-stack__legend {
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-muted);
}

.tech-stack__chips {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.chip {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  cursor: pointer;
  user-select: none;
  transition: background-color var(--transition-fast),
    border-color var(--transition-fast), color var(--transition-fast);
}

.chip:hover {
  border-color: var(--color-border-strong);
  color: var(--color-text);
}

/* Selected state driven by the real checkbox (:has keeps markup honest) */
.chip:has(input:checked) {
  background: var(--color-accent-soft);
  border-color: var(--color-accent);
  color: var(--color-accent);
  font-weight: 550;
}

.chip:has(input:focus-visible) {
  box-shadow: var(--focus-ring);
}

/* ==========================================================================
   Buttons
   ========================================================================== */
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-weight: 600;
  font-size: var(--text-sm);
  cursor: pointer;
  white-space: nowrap;
  transition: background-color var(--transition-fast),
    border-color var(--transition-fast), transform var(--transition-fast);
}

.button:active {
  transform: translateY(1px);
}

.button--primary {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
}

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

.button--secondary {
  background: var(--color-bg-elevated);
  border-color: var(--color-border);
  color: var(--color-text);
}

.button--secondary:hover {
  border-color: var(--color-border-strong);
}

/* ==========================================================================
   Preview panel
   ========================================================================== */
.preview {
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
  position: relative;
}

.preview__toolbar {
  position: sticky;
  top: 0;
  z-index: 10;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
}

.preview__title {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.preview__actions {
  display: flex;
  gap: var(--space-2);
}

.preview__output {
  padding: var(--space-5) var(--space-5) var(--space-7);
}

.preview__placeholder {
  color: var(--color-text-muted);
  font-style: italic;
}

/* Empty & error states — centered, calm, intentional */
.preview__empty,
.preview__error {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-7) var(--space-3);
  text-align: center;
}

.preview__empty-title,
.preview__error-title {
  font-weight: 600;
  color: var(--color-text);
}

.preview__empty-hint,
.preview__error-hint {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}

/* ==========================================================================
   Footer
   ========================================================================== */
.app-footer {
  padding: var(--space-3) var(--space-4);
  background: var(--color-bg);
  border-top: 1px solid var(--color-border);
  text-align: center;
}

.app-footer__text {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

/* ==========================================================================
   Desktop split (>= 768px): two simultaneous panes, toggle hidden
   ========================================================================== */
@media (min-width: 48em) {
  .view-toggle {
    display: none;
  }

  .workspace {
    flex-direction: row;
  }

  .editor,
  .preview {
    flex: 1 1 50%;
    height: 100%;
  }

  .preview {
    border-top: 0;
    border-left: 1px solid var(--color-border);
  }
}