/* Morse Code Oscillator — visualization styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

:root {
  --bg: #050b16;
  --bg-panel: #0c1626;
  --bg-card: #0f1c30;
  --border: #1e3050;
  --text: #e6edf6;
  --text-dim: #94a8c2;
  --accent: #38d0ff;
  --accent-2: #ffb648;
  --danger: #ff5d7a;
  --key-down: #38d0ff;
}

html, body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.55;
  min-height: 100vh;
}

.mc-container {
  max-width: 1400px;
  margin: 0 auto;
  padding: 20px;
}

header h1 {
  font-size: 1.7rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 8px;
  background: linear-gradient(120deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  color: var(--text-dim);
  font-size: 0.95rem;
  max-width: 1000px;
}

.main-layout {
  display: grid;
  grid-template-columns: 280px 1fr;
  gap: 18px;
  margin-top: 18px;
}

.controls-panel {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 16px;
  height: fit-content;
  position: sticky;
  top: 16px;
}

.control-section {
  padding-bottom: 14px;
  margin-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.control-section:last-child {
  border-bottom: none;
  margin-bottom: 0;
  padding-bottom: 0;
}

.control-section h3 {
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 12px;
}

.control-group {
  margin-bottom: 12px;
}

.control-group label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  font-size: 0.85rem;
  color: var(--text-dim);
  margin-bottom: 6px;
}

.val {
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  font-weight: 600;
  font-size: 0.85rem;
}

input[type="range"] {
  width: 100%;
  height: 4px;
  -webkit-appearance: none;
  appearance: none;
  background: var(--border);
  border-radius: 2px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg);
  box-shadow: 0 0 6px rgba(56, 208, 255, 0.5);
}

input[type="range"]::-moz-range-thumb {
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--accent);
  cursor: pointer;
  border: 2px solid var(--bg);
}

.btn-row {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.btn-row button,
.preset-btn {
  flex: 1;
  background: var(--bg-card);
  color: var(--text);
  border: 1px solid var(--border);
  padding: 8px 10px;
  border-radius: 7px;
  font-size: 0.82rem;
  cursor: pointer;
  transition: all 0.15s ease;
}

.btn-row button:hover,
.preset-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-row button.primary {
  background: rgba(56, 208, 255, 0.16);
  border-color: var(--accent);
  color: var(--accent);
}

.preset-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px;
}

.preset-btn.active {
  background: rgba(56, 208, 255, 0.14);
  border-color: var(--accent);
  color: var(--accent);
}

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
  margin-bottom: 10px;
}

.stat-item {
  background: var(--bg-card);
  border-radius: 7px;
  padding: 7px 9px;
}

.stat-label {
  display: block;
  font-size: 0.68rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-dim);
  margin-bottom: 2px;
}

.stat-val {
  display: block;
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
}

.formula-box {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 6px;
  padding: 8px 10px;
  font-family: "SF Mono", "Fira Code", Consolas, monospace;
  font-size: 0.78rem;
  color: var(--text);
  text-align: center;
}

.progress-bar {
  width: 100%;
  height: 6px;
  background: var(--border);
  border-radius: 3px;
  overflow: hidden;
}

.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  transition: width 0.08s linear;
}

.display-panel {
  min-width: 0;
}

.input-card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
  margin-bottom: 16px;
}

.input-card label {
  display: block;
  font-size: 0.78rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--accent);
  margin-bottom: 8px;
}

.input-row {
  display: flex;
  gap: 8px;
  margin-bottom: 10px;
}

#text-input {
  flex: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 9px 12px;
  color: var(--text);
  font-size: 1rem;
  font-family: inherit;
  outline: none;
  transition: border-color 0.15s ease;
}

#text-input:focus {
  border-color: var(--accent);
}

#btn-encode {
  background: rgba(56, 208, 255, 0.16);
  border: 1px solid var(--accent);
  color: var(--accent);
  padding: 9px 16px;
  border-radius: 7px;
  font-size: 0.85rem;
  cursor: pointer;
}

.code-output {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 7px;
  padding: 10px 12px;
  font-family: "SF Mono", "Fira Code", Consolas, monospace;
  font-size: 1.15rem;
  letter-spacing: 0.12em;
  color: var(--accent);
  word-break: break-all;
  min-height: 44px;
}

.input-hint {
  font-size: 0.76rem;
  color: var(--text-dim);
  margin-top: 8px;
}

.viz-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-rows: auto auto;
  gap: 16px;
}

.canvas-card {
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px;
}

.canvas-card.wide {
  grid-column: 1 / -1;
}

.canvas-card h3 {
  font-size: 0.98rem;
  color: var(--text);
  margin-bottom: 4px;
}

.viz-note {
  font-size: 0.78rem;
  color: var(--text-dim);
  margin-bottom: 10px;
}

canvas {
  display: block;
  width: 100%;
  border-radius: 8px;
  background: #02070f;
}

#timeline-canvas {
  height: 150px;
}

#waveform-canvas,
#spectrogram-canvas {
  height: 220px;
}

.education {
  margin-top: 20px;
  background: var(--bg-panel);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 18px;
}

.tabs {
  display: flex;
  gap: 6px;
  margin-bottom: 16px;
  border-bottom: 1px solid var(--border);
}

.tab-btn {
  background: transparent;
  border: none;
  color: var(--text-dim);
  padding: 8px 14px;
  cursor: pointer;
  font-size: 0.9rem;
  border-bottom: 2px solid transparent;
  transition: all 0.15s ease;
}

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

.tab-btn.active {
  color: var(--accent);
  border-bottom-color: var(--accent);
}

.tab-pane {
  display: none;
}

.tab-pane.active {
  display: block;
}

.edu-card {
  margin-bottom: 14px;
}

.edu-card:last-child {
  margin-bottom: 0;
}

.edu-card h3 {
  font-size: 1.02rem;
  color: var(--accent);
  margin-bottom: 6px;
}

.edu-card p {
  font-size: 0.9rem;
  color: var(--text);
  text-align: justify;
}

footer {
  margin-top: 18px;
  padding: 14px;
  text-align: center;
  color: var(--text-dim);
  font-size: 0.78rem;
  border-top: 1px solid var(--border);
}

@media (max-width: 920px) {
  .main-layout {
    grid-template-columns: 1fr;
  }
  .controls-panel {
    position: static;
  }
  .viz-grid {
    grid-template-columns: 1fr;
  }
  .canvas-card.wide {
    grid-column: auto;
  }
}