/* Roux Trainer — Precision dark tokens. All styles reference these. */

:root {
  /* color */
  --color-bg: oklch(15% 0.012 260);
  --color-surface: oklch(20% 0.014 260);
  --color-border: oklch(30% 0.016 260);
  --color-text: oklch(93% 0.008 260);
  --color-text-dim: oklch(70% 0.012 260);
  --color-accent: oklch(80% 0.14 200);
  --color-accent-contrast: oklch(18% 0.03 200);

  /* spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 24px;
  --space-6: 32px;
  --space-7: 48px;

  /* type scale */
  --font-sans: ui-sans-serif, system-ui, -apple-system, sans-serif;
  --font-mono: ui-monospace, "SF Mono", Menlo, monospace;
  --text-sm: clamp(0.8rem, 0.75rem + 0.25vw, 0.9rem);
  --text-base: clamp(1rem, 0.95rem + 0.35vw, 1.125rem);
  --text-lg: clamp(1.25rem, 1.1rem + 0.8vw, 1.6rem);
  --text-xl: clamp(1.6rem, 1.3rem + 1.6vw, 2.25rem);

  /* shape + depth */
  --radius: 10px;
  --shadow: 0 var(--space-1) var(--space-5) oklch(0% 0 0 / 0.45);

  /* interaction */
  --size-tap: 44px; /* iOS minimum comfortable touch target */

  color-scheme: dark;
}

* {
  box-sizing: border-box;
  margin: 0;
}

body {
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.5;
  min-height: 100dvh;
  overscroll-behavior: none; /* no rubber-band scroll while tapping moves */
}

.shell {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  padding: var(--space-4);
  padding-bottom: calc(var(--space-4) + env(safe-area-inset-bottom));
}

.site-header {
  padding-block: var(--space-3);

  & h1 {
    font-size: var(--text-xl);
    font-weight: 650;
    letter-spacing: -0.02em;
  }
}

.stage {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  gap: var(--space-3);
  padding-block: var(--space-3);
}

twisty-player {
  /* cube stays the star but leaves room for the move pad on a phone */
  width: min(100%, 420px, 48dvh);
  aspect-ratio: 1;
  height: auto;
  border-radius: var(--radius);
  background: var(--color-surface);
  box-shadow: var(--shadow);
}

button {
  font: inherit;
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-accent-contrast);
  background: var(--color-accent);
  border: none;
  border-radius: var(--radius);
  padding: var(--space-3) var(--space-6);
  cursor: pointer;

  &:hover:not(:disabled) {
    filter: brightness(1.08);
  }

  &:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: var(--space-1);
  }

  &:disabled {
    opacity: 0.55;
    cursor: default;
  }
}

/* quiet buttons: move pad + secondary actions (accent stays for Scramble) */
.btn-quiet {
  color: var(--color-text);
  background: var(--color-surface);
  border: 1px solid var(--color-border);

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

/* solved / stage indicator — text + icon, never color alone */
.status {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-base);
  font-weight: 600;

  & .status-icon {
    font-family: var(--font-mono);
    color: var(--color-accent);
  }
}

/* move history — monospace alg text, last move marked (bold + underline) */
.history {
  width: min(100%, 420px);
  min-height: calc(var(--space-7) + var(--space-1));
  max-height: calc(2 * var(--space-7));
  overflow-y: auto;
  display: flex;
  flex-wrap: wrap;
  align-content: flex-start;
  align-items: baseline;
  gap: var(--space-1) var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-2) var(--space-3);

  & .history-move.last {
    font-weight: 700;
    text-decoration: underline;
    text-underline-offset: var(--space-1);
  }

  & .history-empty {
    color: var(--color-text-dim);
  }
}

/* move input pad */
.pad {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  width: min(100%, 420px);
  touch-action: manipulation;
}

.movepad {
  display: grid;
  grid-template-columns: repeat(6, 1fr);
  gap: var(--space-2);

  & .span-2 {
    grid-column: span 2;
  }
}

.btn-move {
  font-family: var(--font-mono);
  padding: var(--space-2);
}

/* ′ toggle on: every pad button advertises its prime variant */
.movepad.prime .btn-move::after {
  content: "′";
}

.pad button {
  min-height: var(--size-tap);
  touch-action: manipulation;
  -webkit-user-select: none;
  user-select: none;
  -webkit-touch-callout: none;
}

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

  & > button {
    flex: 1;
    padding-inline: var(--space-2);
  }
}

.tempo {
  flex: 2;
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  min-height: var(--size-tap);

  & input[type="range"] {
    flex: 1;
    min-width: 0;
    accent-color: var(--color-accent);
    min-height: var(--size-tap);
    margin: 0;

    &:focus-visible {
      outline: 2px solid var(--color-accent);
      outline-offset: var(--space-1);
    }
  }

  & .tempo-value {
    font-family: var(--font-mono);
    min-width: calc(var(--space-6) + var(--space-2));
    text-align: right;
  }
}

.scramble {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  color: var(--color-text-dim);
  text-align: center;
  overflow-wrap: break-word;
  width: min(100%, 420px);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-3) var(--space-4);
  min-height: calc(var(--space-7) + var(--space-2));
  display: grid;
  place-items: center;
}

/* desktop keyboard legend */
.keymap {
  width: min(100%, 420px);
  font-size: var(--text-sm);
  color: var(--color-text-dim);

  & summary {
    cursor: pointer;
    min-height: var(--size-tap);
    display: flex;
    align-items: center;

    &:focus-visible {
      outline: 2px solid var(--color-accent);
      outline-offset: var(--space-1);
    }
  }

  & .keymap-list {
    font-family: var(--font-mono);
    margin-top: var(--space-2);
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}