:root {
    --bg-dark: #000000;
    --bg-light: #0C0C0E;
    --accent-glow: rgba(255, 255, 255, 0.8);
    --ring-base: rgba(255, 255, 255, 0.15);
    --ring-target: rgba(255, 255, 255, 0.6);
    --text-primary: #FFFFFF;
    --text-dim: rgba(255, 255, 255, 0.4);
    --error-red: #FF3B30;
    --success-blue: #0A84FF;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    user-select: none;
    -webkit-user-select: none;
    touch-action: manipulation;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: radial-gradient(circle at center, var(--bg-light) 0%, var(--bg-dark) 100%);
    color: var(--text-primary);
    height: 100vh;
    width: 100vw;
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: filter 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
}

body.dead {
    filter: grayscale(100%) contrast(1.2);
}

#game-container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    padding: 60px 20px;
}

#bg-flash-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, rgba(255, 255, 255, 0.15) 0%, transparent 70%);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1);
    z-index: 1;
}

#bg-flash-overlay.flash {
    opacity: 1;
    transition: opacity 0.05s ease-out;
}

#score-display {
    text-align: center;
    display: flex;
    flex-direction: column;
    gap: 8px;
    z-index: 10;
}

#streak-label {
    font-size: 12px;
    letter-spacing: 4px;
    color: var(--text-dim);
    font-weight: 600;
}

#streak-count {
    font-size: 64px;
    font-weight: 300;
    letter-spacing: -2px;
    line-height: 1;
    text-shadow: 0 0 20px rgba(255,255,255,0.2);
    transition: transform 0.1s ease, text-shadow 0.3s ease;
}

#streak-count.pulse {
    transform: scale(1.1);
    text-shadow: 0 0 30px rgba(255,255,255,0.6);
}

#lives-display {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 12px;
}

.life-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.15);
    transition: all 0.3s ease;
}

.life-dot.active {
    background: var(--text-primary);
    box-shadow: 0 0 10px var(--accent-glow);
}

#ring-container {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 300px;
    height: 300px;
    display: flex;
    justify-content: center;
    align-items: center;
}

#target-ring, #dynamic-ring {
    position: absolute;
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

#target-ring {
    width: 180px;
    height: 180px;
    border: 4px solid var(--ring-target);
    box-shadow: 0 0 15px rgba(255,255,255,0.1), inset 0 0 15px rgba(255,255,255,0.1);
    transition: all 0.3s ease;
}

#target-ring::before {
    content: '';
    position: absolute;
    top: -12px; left: -12px; right: -12px; bottom: -12px;
    border: 2px dashed rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    animation: rotateRing var(--dash-speed, 12s) linear infinite;
    pointer-events: none;
}

#target-ring::after {
    content: '';
    position: absolute;
    top: -4px; left: -4px; right: -4px; bottom: -4px;
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    box-shadow: 0 0 20px rgba(0, 195, 255, 0.2), inset 0 0 20px rgba(0, 195, 255, 0.2);
    animation: rotateRingReverse calc(var(--dash-speed, 12s) * 1.5) linear infinite;
    pointer-events: none;
}

@keyframes rotateRing {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

@keyframes rotateRingReverse {
    from { transform: rotate(360deg); }
    to { transform: rotate(-360deg); }
}

@keyframes beatPulse {
    0% { transform: translate(-50%, -50%) scale(1); }
    50% { transform: translate(-50%, -50%) scale(1.04); }
    100% { transform: translate(-50%, -50%) scale(1); }
}

.beat-sync {
    animation: beatPulse 0.5s infinite ease-in-out; /* 120 BPM = 0.5s */
}

@keyframes screenShake {
    0% { transform: translate(0, 0); }
    20% { transform: translate(-8px, 4px) rotate(-1deg); }
    40% { transform: translate(8px, -4px) rotate(1deg); }
    60% { transform: translate(-4px, 8px) rotate(-1deg); }
    80% { transform: translate(4px, -8px) rotate(1deg); }
    100% { transform: translate(0, 0); }
}

.shake {
    animation: screenShake 0.3s cubic-bezier(.36,.07,.19,.97) both;
}

#dynamic-ring {
    width: 0px;
    height: 0px;
    border: 2px solid var(--accent-glow);
    box-shadow: 0 0 15px var(--accent-glow);
    will-change: width, height, box-shadow;
    transition: box-shadow 0.1s ease, border-color 0.1s ease;
}

#dynamic-ring.overlap-glow {
    border-color: #FFFFFF;
    box-shadow: 0 0 50px #FFFFFF, inset 0 0 30px #FFFFFF;
}

#target-ring.overlap-glow {
    border-color: #FFFFFF;
    box-shadow: 0 0 50px #FFFFFF, inset 0 0 30px #FFFFFF;
}

.flash-perfect {
    animation: perfectGlow 0.4s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes perfectGlow {
    0% { border-color: var(--success-blue); box-shadow: 0 0 40px var(--success-blue); }
    100% { border-color: var(--accent-glow); box-shadow: 0 0 15px var(--accent-glow); }
}

#feedback-text {
    position: absolute;
    top: -40px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 1px;
    opacity: 0;
    transform: translateY(10px);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

#feedback-text.show {
    opacity: 1;
    transform: translateY(0);
}

#instruction {
    font-size: 14px;
    color: var(--text-dim);
    letter-spacing: 0.5px;
    padding-bottom: 20px;
}

/* Glassmorphism Overlay */
#death-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 100;
    opacity: 1;
    transition: opacity 0.4s ease;
}

#death-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.glass-panel {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 24px;
    padding: 40px 30px;
    width: 320px;
    text-align: center;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.5);
    transform: translateY(0) scale(1);
    transition: transform 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

#death-overlay.hidden .glass-panel {
    transform: translateY(20px) scale(0.95);
}

.death-title {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
    color: #fff;
}

.near-miss {
    font-size: 14px;
    color: var(--error-red);
    font-weight: 600;
    margin-bottom: 30px;
    animation: pulseRed 1s infinite alternate;
}

@keyframes pulseRed {
    from { opacity: 0.7; text-shadow: 0 0 5px rgba(255,59,48,0.3); }
    to { opacity: 1; text-shadow: 0 0 15px rgba(255,59,48,0.8); }
}

.cost-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: rgba(0, 0, 0, 0.3);
    padding: 12px 16px;
    border-radius: 12px;
    margin-bottom: 24px;
    font-size: 14px;
    color: rgba(255,255,255,0.7);
}

.diamonds {
    color: #32D74B;
    font-weight: 600;
}

button {
    width: 100%;
    padding: 16px;
    border-radius: 14px;
    border: none;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: 'Inter', sans-serif;
}

button:active {
    transform: scale(0.96);
}

.btn-primary {
    background: #FFFFFF;
    color: #000000;
    margin-bottom: 12px;
    box-shadow: 0 4px 15px rgba(255,255,255,0.2);
}

.btn-secondary {
    background: transparent;
    color: rgba(255,255,255,0.5);
    border: 1px solid rgba(255,255,255,0.1);
}