:root {
    --bg-color: #0a0a0a;
    --cyan: #00ffff;
    --magenta: #ff00ff;
    --grid-color: rgba(255, 255, 255, 0.1);
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    overflow: hidden;
}

.container {
    text-align: center;
    z-index: 1;
}

header {
    margin-bottom: 2rem;
}

.neon-title {
    font-size: 3rem;
    text-transform: uppercase;
    letter-spacing: 5px;
    color: white;
    text-shadow: 0 0 10px var(--cyan), 0 0 20px var(--cyan), 0 0 40px var(--cyan);
    margin-bottom: 0.5rem;
}

#status {
    font-size: 1.2rem;
    letter-spacing: 2px;
}

.player-x {
    color: var(--cyan);
    text-shadow: 0 0 5px var(--cyan);
}

.player-o {
    color: var(--magenta);
    text-shadow: 0 0 5px var(--magenta);
}

.board {
    display: grid;
    grid-template-columns: repeat(3, 120px);
    grid-template-rows: repeat(3, 120px);
    gap: 15px;
    margin: 0 auto;
    padding: 15px;
    background: rgba(255, 255, 255, 0.02);
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.2), inset 0 0 20px rgba(255, 0, 255, 0.2);
}

.cell {
    width: 120px;
    height: 120px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--grid-color);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 3.5rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    border-radius: 8px;
}

.cell:hover:not(.filled) {
    background: rgba(255, 255, 255, 0.08);
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.1);
}

.cell.x {
    color: var(--cyan);
    text-shadow: 0 0 10px var(--cyan), 0 0 20px var(--cyan);
    animation: pulse-cyan 2s infinite;
}

.cell.o {
    color: var(--magenta);
    text-shadow: 0 0 10px var(--magenta), 0 0 20px var(--magenta);
    animation: pulse-magenta 2s infinite;
}

@keyframes pulse-cyan {
    0%, 100% { text-shadow: 0 0 10px var(--cyan), 0 0 20px var(--cyan); }
    50% { text-shadow: 0 0 20px var(--cyan), 0 0 40px var(--cyan), 0 0 60px var(--cyan); }
}

@keyframes pulse-magenta {
    0%, 100% { text-shadow: 0 0 10px var(--magenta), 0 0 20px var(--magenta); }
    50% { text-shadow: 0 0 20px var(--magenta), 0 0 40px var(--magenta), 0 0 60px var(--magenta); }
}

#game-over-banner {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.9);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 100;
    transition: opacity 0.5s ease;
}

#game-over-banner.hidden {
    opacity: 0;
    pointer-events: none;
}

#game-over-text {
    font-size: 4rem;
    margin-bottom: 2rem;
    text-transform: uppercase;
    letter-spacing: 10px;
    animation: flicker 1.5s infinite alternate;
}

@keyframes flicker {
    0%, 19%, 21%, 23%, 25%, 54%, 56%, 100% {
        text-shadow: 0 0 10px #fff, 0 0 20px #fff, 0 0 40px var(--cyan), 0 0 70px var(--cyan);
    }
    20%, 22%, 24%, 55% {
        text-shadow: none;
    }
}

#reset-button {
    padding: 15px 40px;
    font-size: 1.2rem;
    background: transparent;
    color: white;
    border: 2px solid white;
    cursor: pointer;
    letter-spacing: 3px;
    transition: all 0.3s ease;
    box-shadow: 0 0 10px white;
}

#reset-button:hover {
    background: white;
    color: black;
    box-shadow: 0 0 20px white, 0 0 40px white;
}

.winning-cell {
    background: rgba(255, 255, 255, 0.1) !important;
    transform: scale(1.05);
}