/* ===================================================================
   TETRIS #1 — styles.css
   Layout + theme implementation on top of design/design-system.css
   tokens. Uses [data-theme="dark"] for dark mode (default assumed
   light unless tokens in design-system.css set otherwise).
   =================================================================== */

:root {
  --tetris-bg: var(--color-bg, #f4f1ea);
  --tetris-surface: var(--color-surface, #ffffff);
  --tetris-text: var(--color-text, #1c1b19);
  --tetris-muted: var(--color-muted, #6b675f);
  --tetris-border: var(--color-border, #d8d3c7);
  --tetris-primary: var(--color-primary, #c1440e);
  --tetris-accent: var(--color-accent, #2f6f4e);
  --tetris-danger: var(--color-danger, #b3261e);
  --tetris-radius: var(--radius-md, 10px);
  --tetris-shadow: var(--shadow-md, 0 4px 14px rgba(0, 0, 0, 0.12));
  --tetris-font: var(--font-sans, 'Segoe UI', system-ui, sans-serif);
  --tetris-font-mono: var(--font-mono, 'Courier New', monospace);
}

[data-theme="dark"] {
  --tetris-bg: var(--color-bg-dark, #15130f);
  --tetris-surface: var(--color-surface-dark, #211e18);
  --tetris-text: var(--color-text-dark, #f1ede3);
  --tetris-muted: var(--color-muted-dark, #a39d8f);
  --tetris-border: var(--color-border-dark, #3a352b);
  --tetris-primary: var(--color-primary-dark, #e0601f);
  --tetris-accent: var(--color-accent-dark, #4f9d72);
  --tetris-danger: var(--color-danger-dark, #e06057);
  --tetris-shadow: var(--shadow-md-dark, 0 4px 18px rgba(0, 0, 0, 0.5));
}

* {
  box-sizing: border-box;
}

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

.app-shell {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1rem;
}

/* ---------- Header / Nav ---------- */

.app-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 0;
  border-bottom: 2px solid var(--tetris-border);
}

.app-title {
  margin: 0;
  font-size: 1.8rem;
  letter-spacing: 0.05em;
  color: var(--tetris-primary);
}

.app-nav {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.nav-link {
  display: inline-block;
  padding: 0.5rem 0.9rem;
  border-radius: var(--tetris-radius);
  color: var(--tetris-muted);
  text-decoration: none;
  font-weight: 600;
  transition: background-color 0.15s ease, color 0.15s ease;
}

.nav-link:hover {
  background: var(--tetris-surface);
  color: var(--tetris-text);
}

.nav-link.active {
  background: var(--tetris-primary);
  color: #fff;
}

.nav-link:focus-visible,
.btn:focus-visible,
button:focus-visible,
a:focus-visible {
  outline: 3px solid var(--tetris-accent);
  outline-offset: 2px;
}

/* ---------- Main game layout ---------- */

.game-main {
  display: flex;
  flex-wrap: wrap;
  gap: 1.5rem;
  padding: 1.5rem 0;
  align-items: flex-start;
  justify-content: center;
}

.board-area {
  position: relative;
  background: var(--tetris-surface);
  border: 2px solid var(--tetris-border);
  border-radius: var(--tetris-radius);
  box-shadow: var(--tetris-shadow);
  padding: 0.5rem;
  display: inline-flex;
}

#game-board {
  display: block;
  background: #0b0b0d;
  border-radius: calc(var(--tetris-radius) - 4px);
  width: 300px;
  height: 600px;
  max-width: 100%;
}

.side-panel {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  width: 220px;
  flex-shrink: 0;
}

.panel-block {
  background: var(--tetris-surface);
  border: 1px solid var(--tetris-border);
  border-radius: var(--tetris-radius);
  padding: 0.85rem 1rem;
  box-shadow: var(--tetris-shadow);
}

#score-label,
.panel-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--tetris-muted);
  margin-bottom: 0.3rem;
}

.panel-value {
  font-family: var(--tetris-font-mono);
  font-size: 1.6rem;
  font-weight: 700;
  color: var(--tetris-text);
}

#next-piece-canvas {
  display: block;
  margin-top: 0.5rem;
  background: #0b0b0d;
  border-radius: calc(var(--tetris-radius) - 4px);
  width: 100%;
  max-width: 120px;
  height: auto;
}

.controls-block {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.controls-list {
  list-style: none;
  margin: 0.5rem 0 0 0;
  padding: 0;
  font-size: 0.85rem;
  color: var(--tetris-muted);
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

/* ---------- Buttons ---------- */

.btn {
  display: inline-block;
  width: 100%;
  padding: 0.6rem 1rem;
  border: none;
  border-radius: var(--tetris-radius);
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.1s ease, background-color 0.15s ease, opacity 0.15s ease;
}

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

.btn-primary {
  background: var(--tetris-primary);
  color: #fff;
}

.btn-primary:hover {
  opacity: 0.9;
}

.btn-secondary {
  background: transparent;
  color: var(--tetris-text);
  border: 1px solid var(--tetris-border);
}

.btn-secondary:hover {
  background: var(--tetris-bg);
}

/* ---------- Overlays ---------- */

.overlay {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(0, 0, 0, 0.65);
  border-radius: calc(var(--tetris-radius) - 2px);
}

.overlay.hidden {
  display: none;
}

.overlay-box {
  background: var(--tetris-surface);
  color: var(--tetris-text);
  padding: 1.5rem 2rem;
  border-radius: var(--tetris-radius);
  text-align: center;
  box-shadow: var(--tetris-shadow);
  min-width: 220px;
}

.overlay-box h2 {
  margin-top: 0;
  color: var(--tetris-primary);
}

.overlay-box .btn {
  margin-top: 0.75rem;
}

/* ---------- Info sections ---------- */

.info-section {
  background: var(--tetris-surface);
  border: 1px solid var(--tetris-border);
  border-radius: var(--tetris-radius);
  padding: 1.5rem;
  margin: 1rem 0;
  box-shadow: var(--tetris-shadow);
}

.info-section.hidden {
  display: none;
}

.info-section h2 {
  margin-top: 0;
  color: var(--tetris-primary);
}

.score-history {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.score-history li {
  display: flex;
  justify-content: space-between;
  padding: 0.5rem 0.75rem;
  background: var(--tetris-bg);
  border-radius: calc(var(--tetris-radius) - 4px);
  border: 1px solid var(--tetris-border);
  font-family: var(--tetris-font-mono);
}

.empty-state {
  color: var(--tetris-muted);
  font-style: italic;
}

/* ---------- Inline error ---------- */

.inline-error {
  margin: 0.5rem 0;
  padding: 0.65rem 1rem;
  border-radius: var(--tetris-radius);
  background: rgba(179, 38, 30, 0.12);
  color: var(--tetris-danger);
  border: 1px solid var(--tetris-danger);
  font-weight: 600;
}

.inline-error.hidden {
  display: none;
}

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

.app-footer {
  margin-top: auto;
  padding: 1rem 0 1.5rem;
  text-align: center;
  color: var(--tetris-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--tetris-border);
}

/* ---------- Utility ---------- */

.hidden {
  display: none !important;
}

/* ---------- Responsive ---------- */

@media (max-width: 720px) {
  .game-main {
    flex-direction: column;
    align-items: center;
  }

  .side-panel {
    width: 100%;
    max-width: 300px;
  }

  .app-header {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (max-width: 400px) {
  #game-board {
    width: 100%;
    height: auto;
    aspect-ratio: 1 / 2;
  }
}

/* ---------- Reduced motion ---------- */

@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }

  .btn:active {
    transform: none;
  }
}