/* ---------- Tokens ---------- */
:root {
  --color-bg: #f5f5f4;
  --color-surface: #ffffff;
  --color-text: #1c1917;
  --color-muted: #78716c;
  --color-border: #d6d3d1;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-on-accent: #ffffff;
  --color-error: #dc2626;

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --space-1: 8px;
  --space-2: 16px;
  --space-3: 24px;

  --font-sans: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color-scheme: light dark;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #1c1917;
    --color-surface: #292524;
    --color-text: #f5f5f4;
    --color-muted: #a8a29e;
    --color-border: #44403c;
    --color-accent: #3b82f6;
    --color-accent-hover: #60a5fa;
    --color-error: #f87171;
  }
}

/* ---------- Base ---------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

[hidden] {
  display: none !important;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: var(--font-sans);
  background: var(--color-bg);
  color: var(--color-text);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

/* ---------- Layout ---------- */
.app {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-2);
}

.app__title {
  margin: 0;
  font-size: 1.4rem;
  font-weight: 600;
}

.card {
  width: 100%;
  max-width: 560px;
  padding: var(--space-3);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
}

.step {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* ---------- Dropzone ---------- */
.dropzone {
  min-height: 220px;
  padding: var(--space-2);
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: border-color 0.15s, background-color 0.15s;
}

.dropzone:hover,
.dropzone:focus-within,
.dropzone.is-over {
  border-color: var(--color-accent);
  background: color-mix(in srgb, var(--color-accent) 6%, transparent);
}

.dropzone__text {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.dropzone__text strong {
  font-size: 1.1rem;
}

.dropzone__text span {
  color: var(--color-muted);
  font-size: 0.9rem;
}

.dropzone__preview {
  display: none;
  max-width: 100%;
  max-height: 260px;
  border-radius: var(--radius-sm);
}

.dropzone.has-image .dropzone__text {
  display: none;
}

.dropzone.has-image .dropzone__preview {
  display: block;
}

/* ---------- Botones ---------- */
.button {
  font: inherit;
  font-weight: 600;
  padding: 12px var(--space-2);
  border: 1px solid transparent;
  border-radius: 10px;
  background: var(--color-accent);
  color: var(--color-on-accent);
  cursor: pointer;
  transition: background-color 0.15s;
}

.button:hover:not(:disabled) {
  background: var(--color-accent-hover);
}

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

.button:disabled {
  opacity: 0.45;
  cursor: not-allowed;
}

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

.button--secondary:hover:not(:disabled) {
  background: var(--color-bg);
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.toolbar .button {
  flex: 1;
}

/* ---------- Progreso ---------- */
.progress {
  height: 8px;
  overflow: hidden;
  border-radius: 99px;
  background: var(--color-border);
}

.progress__fill {
  width: 0;
  height: 100%;
  border-radius: inherit;
  background: var(--color-accent);
  transition: width 0.2s;
}

/* ---------- Visor ---------- */
.viewer {
  position: relative;
  height: 380px;
  overflow: hidden;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: grab;
  touch-action: none;
  /* Fondo de cuadritos para ver las zonas transparentes */
  background: repeating-conic-gradient(var(--color-border) 0 25%, transparent 0 50%) 0 0 / 20px 20px;
}

.viewer.is-dragging {
  cursor: grabbing;
}

.viewer__stage {
  position: absolute;
  top: 0;
  left: 0;
  transform-origin: 0 0;
}

.viewer__stage svg {
  display: block;
}

.hint {
  margin: 0;
  color: var(--color-muted);
  font-size: 0.8rem;
  text-align: center;
}

.error {
  margin: var(--space-2) 0 0;
  color: var(--color-error);
  font-size: 0.9rem;
  text-align: center;
}