/* Clickable prototype shell (03-screens/index.html). Layout only: every value is a design token.
   The screens inside the phone are the screens in screens/, which use only the design system. */

:root {
  --proto-bezel: var(--space-3);
  --proto-phone-w: calc(var(--size-screen-width) + var(--proto-bezel) * 2);
  --proto-phone-h: calc(var(--size-screen-height) + var(--proto-bezel) * 2);
  --proto-scale: 1;
}

body {
  margin: 0;
  background: var(--color-bg-canvas);
  color: var(--color-text-primary);
  font: var(--type-body);
}

.skip {
  position: absolute;
  top: calc(var(--space-16) * -1);
  left: var(--space-2);
  z-index: 1;
  display: inline-flex;
  align-items: center;
  min-height: var(--size-touch-min);
  padding: 0 var(--space-3);
  border-radius: var(--radius-md);
  background: var(--color-bg-surface);
  font: var(--type-label);
}

.skip:focus-visible {
  top: var(--space-2);
}

/* One column on phones; picker | phone | info from 1100 pt */
.proto {
  display: grid;
  grid-template-areas:
    "head"
    "stage"
    "info"
    "nav";
  gap: var(--space-6);
  padding: var(--space-4) var(--space-screen-margin) var(--space-10);
}

.proto__head {
  grid-area: head;
}

.proto__nav {
  grid-area: nav;
}

.proto__stage {
  grid-area: stage;
  display: flex;
  justify-content: center;
  min-width: 0;
}

.proto__info {
  grid-area: info;
}

.proto__head h1 {
  margin: var(--space-3) 0 var(--space-1);
  font: var(--type-h1);
  letter-spacing: var(--type-h1-tracking);
}

.proto__head p {
  max-width: var(--size-measure);
  margin: 0;
  font: var(--type-callout);
  color: var(--color-text-secondary);
}

.proto__home {
  display: inline-flex;
  align-items: center;
  min-height: var(--size-touch-min);
}

.proto__home img {
  display: block;
}

/* Links in the info panel */
.proto__links {
  display: grid;
  margin: var(--space-3) 0 0;
  padding: 0;
  list-style: none;
}

.proto__links a {
  display: inline-flex;
  align-items: center;
  min-height: var(--size-touch-min);
  font: var(--type-body-strong);
  color: var(--color-text-accent);
}

/* Picker: groups by flow; the current screen is marked with aria-current and a tint */
.proto__nav summary {
  display: flex;
  align-items: center;
  min-height: var(--size-touch-min);
  font: var(--type-body-strong);
  cursor: pointer;
}

.proto__nav h2 {
  margin: var(--space-4) 0 var(--space-1);
  font: var(--type-overline);
  letter-spacing: var(--type-overline-tracking);
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.proto__nav ol {
  display: grid;
  gap: var(--space-1);
  margin: 0;
  padding: 0;
  list-style: none;
}

.proto__nav a {
  display: grid;
  min-height: var(--size-touch-min);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  color: var(--color-text-primary);
  text-decoration: none;
}

.proto__nav a b {
  font: var(--type-label);
}

.proto__nav a span {
  font: var(--type-caption);
  color: var(--color-text-secondary);
}

.proto__nav a:hover {
  background: var(--color-bg-pressed);
}

.proto__nav a[aria-current="page"] {
  background: var(--color-bg-accent-subtle);
  box-shadow: inset 0 0 0 var(--border-width-default) var(--color-border-accent);
}

/* The phone: a 390 × 844 screen in a bezel, scaled down (never up) to fit the window */
.phone {
  flex: none;
  width: calc(var(--proto-phone-w) * var(--proto-scale));
  height: calc(var(--proto-phone-h) * var(--proto-scale));
}

.phone__body {
  width: var(--proto-phone-w);
  height: var(--proto-phone-h);
  padding: var(--proto-bezel);
  border-radius: calc(var(--radius-xl) + var(--proto-bezel));
  background: var(--color-text-primary);
  box-shadow: var(--shadow-e2);
  transform: scale(var(--proto-scale));
  transform-origin: 0 0;
  box-sizing: border-box;
}

.phone iframe {
  display: block;
  width: var(--size-screen-width);
  height: var(--size-screen-height);
  border: 0;
  border-radius: var(--radius-xl);
  background: var(--color-bg-canvas);
}

/* Info: where you are, Previous / Next, links */
.proto__count {
  margin: 0;
  font: var(--type-overline);
  letter-spacing: var(--type-overline-tracking);
  text-transform: uppercase;
  color: var(--color-text-secondary);
}

.proto__info h2 {
  margin: var(--space-1) 0 0;
  font: var(--type-h2);
}

.proto__info p {
  margin: var(--space-1) 0 0;
  color: var(--color-text-secondary);
}

.proto__step {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-4);
}

.proto__info .proto__hint {
  margin-top: var(--space-4);
  font: var(--type-callout);
}

@media (width >= 900px) {
  .proto__stage {
    position: sticky;
    top: var(--space-4);
  }

  .proto {
    grid-template:
      "head stage" auto
      "info stage" auto
      "nav stage" 1fr / minmax(15rem, 18rem) minmax(0, 1fr);
    align-items: start;
  }
}

@media (width >= 1200px) {
  .proto {
    grid-template:
      "head stage info" auto
      "nav stage info" 1fr / minmax(15rem, 18rem) minmax(0, 1fr) minmax(15rem, 18rem);
  }

  .proto__info {
    position: sticky;
    top: var(--space-4);
  }
}