:root {
  --bg: #16181c;
  --bg-elevated: #22252b;
  --text: #e8e6e3;
  --text-dim: #9a9a9a;
  --accent: #7fa650;
  --accent-hover: #93bb61;
  --error: #d9534f;
  --border: #33363d;
  color-scheme: dark;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  display: flex;
  justify-content: center;
  padding: 24px 16px 64px;
}

#app {
  width: 100%;
  max-width: 560px;
}

h1,
h2 {
  margin: 0 0 8px;
}

/* --- Search screen --- */

.search-screen {
  text-align: center;
}

.tagline {
  color: var(--text-dim);
  margin-bottom: 24px;
}

.search-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 24px;
  text-align: left;
}

#username-input {
  font-size: 1.1rem;
  padding: 12px 14px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
}

.preset-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.preset-btn {
  flex: 1 1 auto;
  padding: 8px 10px;
  border-radius: 999px;
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--text);
  cursor: pointer;
  font-size: 0.85rem;
}

.preset-btn.active {
  background: var(--accent);
  border-color: var(--accent);
  color: #10130c;
  font-weight: 600;
}

.slider-label {
  display: block;
  margin-top: 10px;
  font-size: 0.9rem;
  color: var(--text-dim);
}

.slider-label input[type="range"] {
  width: 100%;
  margin-top: 6px;
}

.slider-label input[type="range"]:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.hint {
  color: var(--text-dim);
  font-size: 0.8rem;
  margin: 4px 0 0;
}

.search-btn,
.primary-btn {
  padding: 12px;
  border-radius: 8px;
  border: none;
  background: var(--accent);
  color: #10130c;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
}

.search-btn:hover,
.primary-btn:hover {
  background: var(--accent-hover);
}

.status {
  color: var(--text-dim);
  margin-top: 16px;
}

.error {
  color: var(--error);
  margin-top: 16px;
}

/* --- Puzzle screen --- */

.puzzle-screen {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.puzzle-topbar {
  display: flex;
}

.puzzle-topbar .link-btn {
  padding: 0;
}

.puzzle-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 8px;
  font-size: 0.9rem;
}

.matchup {
  color: var(--text);
}

.side-badge {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 4px 12px;
  font-size: 0.8rem;
  color: var(--text-dim);
}

.board-wrap {
  width: 100%;
  max-width: 560px;
  aspect-ratio: 1 / 1;
  margin: 0 auto;
  border-radius: 8px;
  transition: box-shadow 0.2s ease;
}

.board-wrap.flash-correct {
  box-shadow: 0 0 0 4px var(--accent);
}

.board-wrap.flash-incorrect {
  box-shadow: 0 0 0 4px var(--error);
  animation: shake 0.4s;
}

@keyframes shake {
  0%,
  100% {
    transform: translateX(0);
  }
  25% {
    transform: translateX(-6px);
  }
  75% {
    transform: translateX(6px);
  }
}

.cg-board {
  width: 100%;
  height: 100%;
}

.feedback {
  min-height: 1.5em;
  text-align: center;
}

.result-correct {
  color: var(--accent);
  font-weight: 600;
}

.result-incorrect {
  color: var(--error);
  font-weight: 600;
}

.variation {
  color: var(--text-dim);
  font-size: 0.85rem;
}

.limitation-note {
  color: var(--text-dim);
  font-size: 0.75rem;
}

.puzzle-actions {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 16px;
  flex-wrap: wrap;
}

.link-btn {
  background: none;
  border: none;
  color: var(--text-dim);
  text-decoration: underline;
  cursor: pointer;
  font-size: 0.9rem;
}

.puzzle-counter {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.85rem;
}

.thanks-note {
  text-align: center;
  color: var(--text-dim);
  font-size: 0.8rem;
  margin: 4px 0 0;
}

.thanks-note a {
  color: var(--text-dim);
}

/* --- Summary screen --- */

.summary-screen {
  text-align: center;
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 32px 24px;
}

.summary-screen .primary-btn {
  margin-top: 16px;
}

.app-footer {
  text-align: center;
  margin-top: 24px;
}

@media (prefers-color-scheme: light) {
  :root {
    --bg: #f5f5f3;
    --bg-elevated: #ffffff;
    --text: #1c1e22;
    --text-dim: #6b6b6b;
    --border: #dcdcdc;
    color-scheme: light;
  }
}