:root {
  --bg-color: #0a0a12;
  --text-color: #ffffff;
  --primary-neon: #00f3ff;
  --secondary-neon: #ff0055;
  --accent-color: #ffe600;
  --font-main: "Rubik", sans-serif;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  user-select: none;
}

body {
  background-color: var(--bg-color);
  color: var(--text-color);
  font-family: var(--font-main);
  overflow: hidden;
  height: 100vh;
  width: 100vw;
}

#game-container {
  position: relative;
  width: 100%;
  height: 100%;
}

canvas {
  display: block;
  width: 100%;
  height: 100%;
}

/* Shake Animation Class */
.shake {
  animation: shake 0.5s cubic-bezier(0.36, 0.07, 0.19, 0.97) both;
}

@keyframes shake {
  10%,
  90% {
    transform: translate3d(-1px, 0, 0);
  }
  20%,
  80% {
    transform: translate3d(2px, 0, 0);
  }
  30%,
  50%,
  70% {
    transform: translate3d(-4px, 0, 0);
  }
  40%,
  60% {
    transform: translate3d(4px, 0, 0);
  }
}

#ui-layer {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
}

#hud-top {
  position: absolute;
  top: 20px;
  width: 100%;
  display: flex;
  justify-content: space-between;
  padding: 0 40px;
  z-index: 10;
}

.hud-item {
  font-size: 1.5rem;
  font-weight: 700;
  text-shadow: 0 0 10px var(--primary-neon);
  color: var(--primary-neon);
}

.hud-item span {
  color: var(--text-color);
}

.hud-item.high-score {
  color: var(--accent-color);
  font-size: 1.2rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

#combo-container {
  position: absolute;
  top: 80px;
  left: 40px;
  z-index: 10;
}

#combo-display {
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent-color);
  text-shadow: 0 0 20px var(--secondary-neon);
  transform: rotate(-10deg);
  transition: transform 0.1s;
}

#combo-display.pulse {
  transform: rotate(-10deg) scale(1.2);
}

#combo-display.hidden {
  opacity: 0;
  transform: scale(0);
}

#controls-hint {
  position: absolute;
  bottom: 20px;
  right: 20px;
  z-index: 30;
  pointer-events: auto;
}

.icon-btn {
  background: transparent;
  border: none;
  font-size: 2rem;
  cursor: pointer;
  color: rgba(255, 255, 255, 0.5);
  transition: color 0.3s;
}

.icon-btn:hover {
  color: #fff;
}

.screen {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(10, 10, 18, 0.95);
  backdrop-filter: blur(10px);
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
  transition: opacity 0.3s ease, visibility 0.3s;
  z-index: 20;
}

.screen.active {
  opacity: 1;
  visibility: visible;
  pointer-events: auto;
}

h1.glitch-title {
  font-size: 6rem;
  margin-bottom: 0.5rem;
  color: var(--text-color);
  text-transform: uppercase;
  letter-spacing: 5px;
  text-shadow: 3px 3px var(--secondary-neon), -3px -3px var(--primary-neon);
  animation: glitch 3s infinite;
}

@keyframes glitch {
  0% {
    transform: skew(0deg);
  }
  2% {
    transform: skew(10deg);
  }
  4% {
    transform: skew(-10deg);
  }
  6% {
    transform: skew(0deg);
  }
  100% {
    transform: skew(0deg);
  }
}

.subtitle {
  font-size: 1.5rem;
  margin-bottom: 3rem;
  color: #ccc;
  font-weight: 300;
}

.menu-list {
  display: flex;
  flex-direction: column;
  gap: 20px;
  align-items: center;
  width: 100%;
}

.content-box {
  text-align: right;
  margin-bottom: 3rem;
  font-size: 1.3rem;
  line-height: 1.8;
  max-width: 600px;
  background: rgba(255, 255, 255, 0.05);
  padding: 30px;
  border-radius: 10px;
  border: 1px solid rgba(0, 243, 255, 0.2);
}

.neon-btn {
  background: transparent;
  border: 2px solid var(--primary-neon);
  color: var(--primary-neon);
  padding: 15px 50px;
  font-size: 1.5rem;
  font-family: var(--font-main);
  font-weight: bold;
  cursor: pointer;
  text-transform: uppercase;
  transition: all 0.2s ease;
  box-shadow: 0 0 10px rgba(0, 243, 255, 0.3);
  border-radius: 5px;
  pointer-events: auto;
  min-width: 250px;
  text-align: center;
}

.neon-btn:hover {
  background: var(--primary-neon);
  color: var(--bg-color);
  box-shadow: 0 0 30px rgba(0, 243, 255, 0.6);
  transform: scale(1.05);
}

.neon-btn.secondary {
  border-color: rgba(255, 255, 255, 0.3);
  color: rgba(255, 255, 255, 0.8);
  box-shadow: none;
  font-size: 1.2rem;
  padding: 12px 40px;
}

.neon-btn.secondary:hover {
  border-color: var(--text-color);
  color: var(--text-color);
  background: rgba(255, 255, 255, 0.1);
  box-shadow: 0 0 15px rgba(255, 255, 255, 0.2);
}

#game-over-screen h2 {
  font-size: 4rem;
  color: var(--secondary-neon);
  margin-bottom: 1rem;
  text-shadow: 0 0 20px var(--secondary-neon);
}

.new-high-score {
  color: var(--accent-color);
  font-size: 2rem;
  font-weight: bold;
  margin-top: 10px;
  margin-bottom: 20px;
  animation: blink 1s infinite alternate;
}

.hidden {
  display: none !important;
}

@keyframes blink {
  from {
    opacity: 1;
  }
  to {
    opacity: 0.5;
  }
}

/* Guide Layout */
.guide-layout {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 30px;
  text-align: right;
  max-width: 900px;
}

.guide-section {
  flex: 1 1 250px;
  background: rgba(0, 0, 0, 0.3);
  padding: 20px;
  border-radius: 8px;
  border: 1px solid rgba(0, 243, 255, 0.1);
}

.guide-section h3 {
  color: var(--accent-color);
  margin-bottom: 15px;
  font-size: 1.4rem;
  border-bottom: 2px solid var(--secondary-neon);
  padding-bottom: 5px;
  display: inline-block;
}

.guide-section ul {
  list-style-type: none;
  padding: 0;
}

.guide-section li {
  margin-bottom: 10px;
  font-size: 1.1rem;
  position: relative;
  padding-right: 20px;
}

.guide-section li::before {
  content: "•";
  color: var(--primary-neon);
  position: absolute;
  right: 0;
  font-weight: bold;
}