/* ===== Reset & Base ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
}

body {
  min-height: 100vh;
  background: linear-gradient(to bottom, deepskyblue, lavender);
  font-family: Arial, Helvetica, sans-serif;
  color: #333;
  display: flex;
  flex-direction: column;
  align-items: center;
}

/* ===== Utility ===== */
.hidden {
  display: none !important;
}

/* ===== Header / Title Bar ===== */
.title-bar {
  width: 100%;
  padding: 10px 0;
  text-align: center;
  background-color: gold;
  color: red;
  font-weight: bold;
  font-size: 1.6rem;
  text-shadow: -1px -1px 5px red;
  text-decoration: underline;
  box-shadow: 5px 3px 10px 10px orange;
}

/* ===== Views (Pages) ===== */
.view {
  width: 100%;
  max-width: 700px;
  padding: 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  flex: 1;
}

/* ===== Home / Level Select ===== */
.level-select-heading {
  font-size: 1.6rem;
  background-color: deepskyblue;
  padding: 6px 20px;
  margin-bottom: 20px;
  font-weight: bold;
  border-radius: 4px;
}

.level-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(85px, 1fr));
  gap: 24px;
  margin-bottom: 30px;
  width: 100%;
  max-width: 360px;
}

.level-grid a {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-decoration: none;
}

.level-grid a img {
  width: 85px;
  height: 85px;
  max-width: 100%;
  transition: transform 0.15s;
}

.level-grid a img:hover {
  transform: scale(1.1);
}

/* ===== Custom Levels ===== */
.custom-heading {
  margin-top: 10px;
}

.custom-levels {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 30px;
}

.custom-card {
  background: linear-gradient(135deg, lavender, #e0f0ff);
  border: 2px solid deepskyblue;
  border-radius: 10px;
  padding: 18px 24px;
  text-align: center;
  min-width: 180px;
  box-shadow: 0 4px 12px rgba(0, 191, 255, 0.25);
}

.custom-card h3 {
  margin: 0 0 6px;
  color: #333;
  font-size: 1.15rem;
}

.custom-desc {
  font-size: 0.85rem;
  color: #555;
  margin: 0 0 12px;
}

.custom-card label {
  font-size: 0.9rem;
  color: #333;
  margin-right: 6px;
}

.custom-card select {
  padding: 4px 8px;
  font-size: 0.95rem;
  border-radius: 4px;
  border: 1px solid deepskyblue;
  background: lavender;
  color: #333;
  cursor: pointer;
}

.btn-play-custom {
  display: block;
  margin: 14px auto 0;
  padding: 8px 28px;
  font-size: 1rem;
  font-weight: bold;
  border: 2px solid deepskyblue;
  border-radius: 6px;
  background: deepskyblue;
  color: #333;
  cursor: pointer;
  transition: opacity 0.2s, transform 0.15s;
}

.btn-play-custom:hover {
  opacity: 0.85;
  transform: scale(1.05);
}

/* ===== Game View ===== */
.toolbar {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 12px;
}

.toolbar button {
  padding: 6px 14px;
  font-size: 0.9rem;
  border: 2px solid gold;
  border-radius: 4px;
  cursor: pointer;
  color: #fff;
  background-color: orange;
  font-weight: bold;
  transition: opacity 0.2s;
}

.toolbar button:hover {
  opacity: 0.85;
}

.game-controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

.game-controls button {
  padding: 6px 16px;
  font-size: 0.9rem;
  color: purple;
  background-color: lightblue;
  border: 2px solid skyblue;
  border-radius: 4px;
  box-shadow: 1px 1px 5px 5px grey;
  cursor: pointer;
  font-weight: bold;
  transition: opacity 0.2s;
}

.game-controls button:hover {
  opacity: 0.85;
}

.level-badge {
  color: purple;
  font-size: 1.3rem;
  border: 1px solid purple;
  text-shadow: 1px 1px 1px grey;
  box-shadow: 1px 1px 5px 5px orange;
  padding: 4px 12px;
  border-radius: 4px;
  background-color: #fff;
}

/* ===== Game Board ===== */
.board-container {
  margin-bottom: 20px;
}

.board {
  border-collapse: collapse;
  background-color: lightgrey;
  text-shadow: 1px 1px 1px violet;
  box-shadow: -1px -1px 1px 1px grey;
}

.board td {
  height: 55px;
  width: 55px;
  border: 2px solid white;
  box-shadow: 1px 1px 2px 2px grey;
  font-size: 1.5rem;
  text-align: center;
  cursor: pointer;
  user-select: none;
  transition: background-color 0.15s, transform 0.15s;
}

.board td:hover {
  background-color: #dce8f0;
}

.board td.zero-cell {
  color: green;
  font-weight: bold;
}

/* Swap flash animation */
@keyframes cell-flash {
  0%   { transform: scale(1.15); background-color: lightyellow; }
  100% { transform: scale(1);    background-color: lightgrey; }
}

.board td.cell-flash {
  animation: cell-flash 0.25s ease-out;
}

/* ===== Timer ===== */
.timer {
  font-size: 1.2rem;
  color: red;
  margin-bottom: 16px;
}

/* ===== Result Overlay ===== */
.result-container {
  text-align: center;
  padding: 30px;
  border-radius: 8px;
  margin-top: 10px;
}

.result-container.win {
  box-shadow: 2px 2px 5px 5px green;
}

.result-container.lose {
  box-shadow: 2px 2px 5px 5px red;
}

.result-container h2 {
  font-size: 2rem;
  margin-bottom: 8px;
}

.result-container p {
  font-size: 1.4rem;
  margin-bottom: 16px;
}

.result-container .timer-result {
  font-size: 1.3rem;
  color: purple;
  box-shadow: 1px 1px 3px 3px gold;
  display: inline-block;
  padding: 4px 12px;
  border-radius: 4px;
  margin-bottom: 16px;
}

.result-container button {
  padding: 10px 24px;
  font-size: 1rem;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  font-weight: bold;
  margin: 6px;
  transition: opacity 0.2s;
}

.result-container button:hover {
  opacity: 0.85;
}

.btn-replay {
  background-color: #4caf50;
}

.btn-home {
  background-color: #2196f3;
}

/* ===== Footer ===== */
.footer {
  width: 100%;
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 10px;
  padding: 10px 16px;
  margin-top: auto;
}

.footer img {
  width: 40px;
  height: 40px;
}

.footer .gh-link svg {
  transition: opacity 0.2s;
}

.footer .gh-link:hover svg {
  opacity: 0.7;
}

/* ===== Best-time badge (home screen) ===== */
.best-badge {
  display: block;
  margin-top: 4px;
  font-size: 0.7rem;
  color: #555;
  background: rgba(255, 255, 255, 0.7);
  padding: 1px 6px;
  border-radius: 3px;
}

/* ===== Best-time (result screen) ===== */
.best-time {
  font-size: 1rem;
  color: deepskyblue;
  margin-bottom: 14px;
  font-weight: bold;
}

/* ===== Responsive ===== */
@media (max-width: 520px) {
  .title-bar {
    font-size: 1.2rem;
  }

  .level-grid {
    gap: 14px;
    max-width: 260px;
  }

  .level-grid a img {
    width: 65px;
    height: 65px;
  }

  .board td {
    height: 38px;
    width: 38px;
    font-size: 1rem;
  }

  .toolbar button,
  .game-controls button {
    font-size: 0.8rem;
    padding: 4px 10px;
  }

  .custom-levels {
    flex-direction: column;
    align-items: center;
    gap: 16px;
  }

  .custom-card {
    min-width: 160px;
    padding: 14px 18px;
  }
}