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

:root {
  --color-correct: #6aaa64;
  --color-present: #c9b458;
  --color-absent: #787c7e;
  --color-empty: #ffffff;
  --color-tbd: #ffffff;
  --tile-border: #d3d6da;
  --tile-border-filled: #878a8c;
  --text: #1a1a1b;
  --bg: #ffffff;
  --header-border: #d3d6da;
  --key-bg: #d3d6da;
  --key-text: #1a1a1b;
}

body {
  font-family: 'Clear Sans', 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-x: hidden;
}

/* Header */
header {
  width: 100%;
  border-bottom: 1px solid var(--header-border);
}

nav {
  max-width: 500px;
  margin: 0 auto;
  padding: 0 1rem;
  height: 50px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

nav h1 {
  font-size: 1.4rem;
  font-weight: 700;
  letter-spacing: 0.1rem;
  text-transform: uppercase;
}

.back {
  font-size: 0.85rem;
  color: var(--color-absent);
  text-decoration: none;
}

.back:hover {
  color: var(--text);
}

/* Message toast */
#message {
  position: fixed;
  top: 70px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--text);
  color: var(--bg);
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  font-size: 0.9rem;
  font-weight: 700;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.15s;
  z-index: 100;
  white-space: nowrap;
}

#message.show {
  opacity: 1;
}

/* Board */
main {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem 0;
}

#board {
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.row {
  display: flex;
  gap: 5px;
}

.tile {
  width: 62px;
  height: 62px;
  border: 2px solid var(--tile-border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  font-weight: 700;
  text-transform: uppercase;
  user-select: none;
  transition: border-color 0.05s;
}

.tile[data-state="tbd"] {
  border-color: var(--tile-border-filled);
}

.tile[data-state="correct"] {
  background: var(--color-correct);
  border-color: var(--color-correct);
  color: #fff;
}

.tile[data-state="present"] {
  background: var(--color-present);
  border-color: var(--color-present);
  color: #fff;
}

.tile[data-state="absent"] {
  background: var(--color-absent);
  border-color: var(--color-absent);
  color: #fff;
}

/* Keyboard */
#keyboard {
  width: 100%;
  max-width: 500px;
  padding: 0 0.5rem 1rem;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.keyboard-row {
  display: flex;
  justify-content: center;
  gap: 6px;
}

.key {
  height: 58px;
  min-width: 43px;
  padding: 0;
  border: none;
  border-radius: 4px;
  background: var(--key-bg);
  color: var(--key-text);
  font-size: 0.85rem;
  font-weight: 700;
  cursor: pointer;
  user-select: none;
  flex: 1;
  max-width: 43px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.1s, color 0.1s;
}

.key.wide {
  min-width: 65px;
  max-width: 65px;
  font-size: 0.75rem;
}

.key[data-state="correct"] {
  background: var(--color-correct);
  color: #fff;
}

.key[data-state="present"] {
  background: var(--color-present);
  color: #fff;
}

.key[data-state="absent"] {
  background: var(--color-absent);
  color: #fff;
}

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

@keyframes flip {
  0%   { transform: rotateX(0deg); }
  50%  { transform: rotateX(-90deg); }
  100% { transform: rotateX(0deg); }
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%       { transform: translateX(-4px); }
  40%       { transform: translateX(4px); }
  60%       { transform: translateX(-4px); }
  80%       { transform: translateX(4px); }
}

.tile.pop {
  animation: pop 0.1s ease-in-out;
}

.tile.flip {
  animation: flip 0.5s ease-in-out;
}

.row.shake {
  animation: shake 0.4s ease-in-out;
}

/* Responsive */
@media (max-width: 400px) {
  .tile {
    width: 52px;
    height: 52px;
    font-size: 1.6rem;
  }

  .key {
    min-width: 32px;
    max-width: 32px;
    height: 50px;
    font-size: 0.75rem;
  }

  .key.wide {
    min-width: 50px;
    max-width: 50px;
  }
}