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

:root {
  --color-bg: #090909;
  --color-surface: #1e1e1e;
  --color-border: #333333;
  --color-text: #f0f0f0;
  --color-muted: #888888;
  --color-accent: #00ff41;
  --font-sans: system-ui, -apple-system, sans-serif;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  min-height: 100dvh;
}

/* ── 설정 화면 ─────────────────────────── */

#settings-screen {
  display: flex;
  flex-direction: column;
  gap: 28px;
  max-width: 480px;
  margin: 0 auto;
  padding: 32px 20px 40px;
}

.app-title {
  font-family: 'Orbitron', sans-serif;
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: 2px;
  text-align: center;
  color: var(--color-accent);
  text-shadow: 0 0 12px var(--color-accent), 0 0 24px var(--color-accent);
}

.section {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.section-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--color-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

#input-text {
  width: 100%;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 10px;
  color: var(--color-text);
  font-size: 1.1rem;
  padding: 12px 14px;
  resize: none;
  outline: none;
  font-family: inherit;
  line-height: 1.5;
}

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

/* 색상 팔레트 */

#color-palette {
  display: flex;
  gap: 14px;
}

.color-btn {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 3px solid transparent;
  cursor: pointer;
  flex-shrink: 0;
  transition: transform 0.15s, border-color 0.15s;
}

.color-btn:hover {
  transform: scale(1.1);
}

.color-btn.selected {
  border-color: #ffffff;
  transform: scale(1.15);
}

.color-pink   { background: #ff2d78; }
.color-green  { background: #00ff41; }
.color-yellow { background: #ffe600; }
.color-cyan   { background: #00e5ff; }
.color-white  { background: #ffffff; }
.color-orange { background: #ff7700; }

/* 슬라이더 */

input[type="range"] {
  width: 100%;
  accent-color: var(--color-accent);
  cursor: pointer;
  height: 6px;
}

/* 저작권 */

.copyright {
  text-align: center;
  font-size: 0.75rem;
  color: var(--color-muted);
  letter-spacing: 0.5px;
}

/* 방향 버튼 그룹 */

.dir-group {
  display: flex;
  border-radius: 10px;
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.dir-btn {
  flex: 1;
  padding: 10px 8px;
  background: var(--color-surface);
  color: var(--color-muted);
  border: none;
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.15s, color 0.15s;
}

.dir-btn + .dir-btn {
  border-left: 1px solid var(--color-border);
}

.dir-btn.selected {
  background: var(--color-accent);
  color: #fff;
}

/* 깜빡임 토글 */

.toggle {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
}

.toggle input {
  display: none;
}

.toggle-slider {
  width: 52px;
  height: 28px;
  background: var(--color-border);
  border-radius: 14px;
  position: relative;
  transition: background 0.2s;
}

.toggle-slider::after {
  content: '';
  position: absolute;
  width: 22px;
  height: 22px;
  background: #fff;
  border-radius: 50%;
  top: 3px;
  left: 3px;
  transition: transform 0.2s;
}

.toggle input:checked + .toggle-slider {
  background: var(--color-accent);
}

.toggle input:checked + .toggle-slider::after {
  transform: translateX(24px);
}

/* 시작 버튼 */

#start-btn {
  margin-top: 8px;
  width: 100%;
  padding: 18px;
  background: var(--color-accent);
  color: #fff;
  border: none;
  border-radius: 14px;
  font-size: 1.2rem;
  font-weight: 700;
  cursor: pointer;
  letter-spacing: 2px;
  transition: opacity 0.15s;
}

#start-btn:hover {
  opacity: 0.88;
}

/* ── 전광판 화면 ─────────────────────────── */

#led-screen {
  position: fixed;
  inset: 0;
  background: #000000;
  display: flex;
  align-items: center;
  justify-content: center;
}

#led-screen[hidden] {
  display: none;
}

#led-canvas {
  display: block;
  width: 100%;
  height: 100%;
}

#tap-hint {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.3);
  pointer-events: none;
  transition: visibility 0s linear 5s, color 0s linear 5s;
}

#tap-hint.hidden {
  visibility: hidden;
  color: transparent;
}