*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg: #121213;
  --header-bg: #1a1a1b;
  --border: #3a3a3c;
  --tile-border-empty: #3a3a3c;
  --tile-border-filled: #565758;
  --correct: #538d4e;
  --present: #b59f3b;
  --absent: #3a3a3c;
  --text: #ffffff;
  --key-bg: #818384;
  --toast-bg: #ffffff;
  --toast-text: #000000;
  --key-backspace-bg: #d46216;

  /*
   * Fluid tile size:
   *   width-limited  → (100vw - 32px padding - 4×5px gap) / 5 ≈ 20vw - 10px
   *   height-limited → leaves ~300px for header + keyboard + button + gaps
   *   → available = 100dvh - 300px, per tile = that / 6 ≈ 16.7dvh - 50px
   * Take the smaller of the two; clamp between 34px and 70px.
   */
  --tile-size: clamp(34px, min(calc(20vw - 10px), calc(16.7dvh - 50px)), 70px);
  --tile-gap:  clamp(3px, 0.8vmin, 6px);
  --tile-font: clamp(1rem, calc(var(--tile-size) * 0.48), 2.2rem);

  /*
   * Fluid key sizes.
   * Top row has 11 keys + 10 gaps; keyboard max-width ~500px.
   * key-w = (min(100vw, 500px) - 2×8px - 10×gap) / 11
   */
  --key-gap:  clamp(3px, 1vw, 7px);
  --key-h:    clamp(36px, 5.8dvh, 58px);
  --key-w:    clamp(22px, calc((min(100vw, 500px) - 16px - 10 * var(--key-gap)) / 11), 44px);
  --key-wide: clamp(34px, calc(var(--key-w) * 1.55), 66px);
  --key-font: clamp(1.5rem, 6vw, 1.85rem);

  --main-gap: clamp(8px, 1.8dvh, 20px);
  --header-h: clamp(44px, 7dvh, 64px);
}

/* ── Base ── */
html {
  min-height: 100%;
}

body {
  min-height: 100dvh;
  overflow-y: auto;
  background: var(--bg);
  color: var(--text);
  font-family: 'Segoe UI', Arial, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* ── Header ── */
header {
  flex-shrink: 0;
  width: 100%;
  height: var(--header-h);
  background: var(--header-bg);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
}

header h1 {
  font-size: clamp(1.2rem, 4vw, 2rem);
  font-weight: 700;
  letter-spacing: 0.2em;
}

/* ── Toast ── */
#toast-container {
  position: fixed;
  top: calc(var(--header-h) + 12px);
  left: 50%;
  transform: translateX(-50%);
  z-index: 100;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  pointer-events: none;
  white-space: nowrap;
}

.toast {
  background: var(--toast-bg);
  color: var(--toast-text);
  font-weight: 700;
  padding: 10px 18px;
  border-radius: 6px;
  font-size: clamp(0.8rem, 3vw, 0.95rem);
  animation: fadeInOut 2s ease forwards;
}

@keyframes fadeInOut {
  0%   { opacity: 0; transform: translateY(-6px); }
  15%  { opacity: 1; transform: translateY(0); }
  75%  { opacity: 1; }
  100% { opacity: 0; }
}

/* ── Main ── */
main {
  flex: 1;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-evenly;
  padding: var(--main-gap) 8px;
  gap: 0;
}

/* ── Board ── */
#board {
  display: flex;
  flex-direction: column;
  gap: var(--tile-gap);
}

.board-row {
  display: flex;
  gap: var(--tile-gap);
}

.tile {
  width: var(--tile-size);
  height: var(--tile-size);
  border: 2px solid var(--tile-border-empty);
  background: var(--bg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--tile-font);
  font-weight: 700;
  text-transform: uppercase;
  user-select: none;
  transition: border-color 0.05s;
}

.tile[data-letter] {
  border-color: var(--tile-border-filled);
}

/* pop: letter typed */
.tile.pop {
  animation: pop 0.1s ease;
}

@keyframes pop {
  0%   { transform: scale(1); }
  50%  { transform: scale(1.12); }
  100% { transform: scale(1); }
}

/* flip: reveal */
.tile.flip {
  animation: flip 0.5s ease forwards;
}

@keyframes flip {
  0%   { transform: rotateX(0deg); }
  49%  { transform: rotateX(-90deg); }
  50%  { transform: rotateX(-90deg); background: var(--flip-color, var(--absent)); border-color: var(--flip-color, var(--absent)); color: #fff; }
  100% { transform: rotateX(0deg); background: var(--flip-color, var(--absent)); border-color: var(--flip-color, var(--absent)); color: #fff; }
}

.tile.correct { --flip-color: var(--correct); }
.tile.present { --flip-color: var(--present); }
.tile.absent  { --flip-color: var(--absent);  }

/* shake: invalid word */
.board-row.shake {
  animation: shake 0.5s ease;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  15%, 55%  { transform: translateX(-5px); }
  35%, 75%  { transform: translateX(5px); }
}

/* bounce: win */
.tile.bounce {
  animation: bounce 0.6s ease forwards;
}

@keyframes bounce {
  0%, 100% { transform: translateY(0); }
  40%       { transform: translateY(-18px); }
  65%       { transform: translateY(-8px); }
}

/* ── Keyboard ── */
#keyboard[hidden] {
  display: none;
}

#keyboard {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--key-gap);
}

.key-row {
  display: flex;
  gap: var(--key-gap);
}

.key {
  height: var(--key-h);
  width: var(--key-w);
  border: none;
  border-radius: 4px;
  background: var(--key-bg);
  color: var(--text);
  font-size: var(--key-font);
  font-weight: 700;
  cursor: pointer;
  user-select: none;
  transition: background 0.2s, color 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

.key-wide {
  width: var(--key-wide);
  font-size: clamp(1.2rem, 3.5vw, 1.7rem);
}

.key:active {
  filter: brightness(0.82);
}

.key.correct { background: var(--correct); color: #fff; }
.key.present { background: var(--present); color: #fff; }
.key.absent  { background: var(--absent);  color: #fff; }

.key-enter {
  background: var(--correct);
  color: #fff;
}

.key-backspace {
  background: var(--key-backspace-bg);
  color: #fff;
}

/* ── Solution display (replaces keyboard when game ends) ── */
#solution-display {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  /* Match the keyboard's approximate height so the layout stays stable */
  min-height: calc(3 * var(--key-h) + 2 * var(--key-gap));
  gap: 6px;
  animation: fadeInUp 0.4s ease;
}

#solution-display[hidden] {
  display: none;
}

#solution-label {
  font-size: clamp(0.7rem, 2.2vw, 0.85rem);
  color: var(--key-bg);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

#solution-word {
  font-size: clamp(1.6rem, 6vw, 2.6rem);
  font-weight: 700;
  letter-spacing: 0.25em;
  color: var(--correct);
}

@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ── Button row ── */
#btn-row {
  display: flex;
  gap: clamp(8px, 2vw, 16px);
  align-items: center;
}

#new-game-btn,
#reveal-btn {
  padding: clamp(8px, 1.5dvh, 12px) clamp(14px, 4vw, 28px);
  border: none;
  border-radius: 6px;
  color: #fff;
  font-size: clamp(0.8rem, 2.8vw, 1rem);
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 0.04em;
  transition: filter 0.15s;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
}

#new-game-btn {
  background: var(--correct);
}

#reveal-btn {
  background: #555;
}

#new-game-btn:hover,
#reveal-btn:hover {
  filter: brightness(1.18);
}

/* ── Modal ── */
#modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 200;
}

#modal-overlay[hidden] {
  display: none;
}

#modal {
  background: #1a1a1b;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: clamp(20px, 5vw, 36px) clamp(24px, 6vw, 48px);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
  max-width: 90vw;
}

#modal-text {
  font-size: clamp(1rem, 4vw, 1.3rem);
  font-weight: 700;
  text-align: center;
}

#modal-btns {
  display: flex;
  gap: 12px;
}

#modal-cancel,
#modal-confirm {
  padding: 10px 22px;
  border: none;
  border-radius: 6px;
  font-size: clamp(0.85rem, 3vw, 1rem);
  font-weight: 700;
  cursor: pointer;
  -webkit-tap-highlight-color: transparent;
  transition: filter 0.15s;
}

#modal-cancel {
  background: #444;
  color: #fff;
}

#modal-confirm {
  background: #c0392b;
  color: #fff;
}

#modal-cancel:hover,
#modal-confirm:hover {
  filter: brightness(1.18);
}