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

body {
    background: #0a0a16;
    color: #e0e0ff;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    overflow-x: hidden;
    padding: 20px;
}

.container {
    max-width: 800px;
    width: 100%;
    text-align: center;
}

.header {
    margin-bottom: 20px;
    position: relative;
}

h1 {
    font-size: 3.5rem;
    margin-bottom: 10px;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: transparent;
    background: linear-gradient(90deg, #00ffff, #ff00ff);
    -webkit-background-clip: text;
    background-clip: text;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.5);
    animation: pulse 3s infinite alternate;
}

@keyframes pulse {
    0% { text-shadow: 0 0 10px rgba(0, 255, 255, 0.5); }
    100% { text-shadow: 0 0 20px rgba(255, 0, 255, 0.7), 0 0 30px rgba(255, 0, 255, 0.5); }
}

.subtitle {
    font-size: 1.2rem;
    color: #a0a0ff;
    margin-bottom: 20px;
}

.mode-selection {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 25px;
}

.mode-btn {
    background: rgba(16, 16, 32, 0.8);
    border: 1px solid #00ffff;
    color: #00ffff;
    padding: 8px 20px;
    font-size: 0.9rem;
    border-radius: 20px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.mode-btn:hover {
    background: rgba(0, 255, 255, 0.1);
    box-shadow: 0 0 10px rgba(0, 255, 255, 0.3);
}

.mode-btn.active {
    background: #00ffff;
    color: #0a0a16;
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.5);
    font-weight: bold;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    background: rgba(16, 16, 32, 0.7);
    padding: 15px 25px;
    border-radius: 10px;
    border: 1px solid rgba(0, 255, 255, 0.2);
    box-shadow: 0 0 15px rgba(0, 255, 255, 0.1);
}

.player-info {
    display: flex;
    flex-direction: column;
    align-items: center;
    min-width: 80px;
}

.player-label {
    font-size: 1.1rem;
    margin-bottom: 5px;
    color: #a0a0ff;
}

.player-name {
    font-size: 1.3rem;
    font-weight: bold;
    color: #00ffff;
}

.current-player {
    color: #ff00ff;
    text-shadow: 0 0 10px rgba(255, 0, 255, 0.7);
}

.score {
    font-size: 2rem;
    font-weight: bold;
    color: #00ffff;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.7);
}

.game-board {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-gap: 10px;
    margin: 0 auto 30px;
    max-width: 400px;
    background: rgba(16, 16, 32, 0.7);
    padding: 20px;
    border-radius: 15px;
    border: 1px solid rgba(0, 255, 255, 0.2);
    box-shadow: 0 0 20px rgba(0, 255, 255, 0.1);
    position: relative;
}

.cell {
    aspect-ratio: 1;
    background: rgba(10, 10, 22, 0.8);
    border: 2px solid rgba(0, 255, 255, 0.3);
    border-radius: 5px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 3rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
    z-index: 1;
}

.cell:hover {
    background: rgba(20, 20, 40, 0.8);
    border-color: rgba(255, 0, 255, 0.5);
    box-shadow: 0 0 15px rgba(255, 0, 255, 0.3);
}

.cell.x {
    color: #00ffff;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.7);
}

.cell.o {
    color: #ff00ff;
    text-shadow: 0 0 10px rgba(255, 0, 255, 0.7);
}

.winning-cell {
    background-color: rgba(255, 255, 255, 0.1);
}

.winning-line {
    position: absolute;
    height: 4px;
    background-color: white;
    width: 0;
    transform-origin: left center;
    transition: width 0.5s cubic-bezier(0.22, 0.61, 0.36, 1);
    z-index: 10;
    border-radius: 2px;
    pointer-events: none;
    display: none;
}

.winning-line.active {
    display: block;
}

.winning-line.x-win {
    background-color: #00ffff;
    box-shadow: 0 0 10px #00ffff, 0 0 20px #00ffff, 0 0 30px #00ffff;
}

.winning-line.o-win {
    background-color: #ff00ff;
    box-shadow: 0 0 10px #ff00ff, 0 0 20px #ff00ff, 0 0 30px #ff00ff;
}

.controls {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-bottom: 30px;
}

button.control-btn {
    background: linear-gradient(45deg, #00aaff, #aa00ff);
    border: none;
    color: white;
    padding: 12px 25px;
    font-size: 1.1rem;
    border-radius: 30px;
    cursor: pointer;
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: bold;
    box-shadow: 0 0 15px rgba(170, 0, 255, 0.5);
}

button.control-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 0 20px rgba(170, 0, 255, 0.7);
}

button.control-btn:active {
    transform: translateY(1px);
}

.game-status {
    font-size: 1.5rem;
    margin-bottom: 20px;
    min-height: 40px;
    color: #00ffff;
    text-shadow: 0 0 10px rgba(0, 255, 255, 0.7);
}

.win-message {
    color: #ff00ff;
    text-shadow: 0 0 10px rgba(255, 0, 255, 0.7);
    animation: pulse 1.5s infinite;
}

.grid-lines {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 0;
    opacity: 0.1;
}

.grid-line {
    position: absolute;
    background: linear-gradient(90deg, transparent, #00ffff, transparent);
}

.grid-line.horizontal {
    width: 100%;
    height: 1px;
}

.grid-line.vertical {
    width: 1px;
    height: 100%;
}

.particles {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: -2;
}

.footer {
    margin-top: 30px;
    display: flex;
    justify-content: center;
    width: 100%;
}

.github-btn {
    font-family: inherit;
    cursor: pointer;
    background: #000000;
    color: #ffffff;
    border: 1px solid rgba(255,255,255,0.1);
    padding: 12px 25px;
    font-size: 16px;
    font-weight: 700;
    border-radius: 100px;
    transition: all 0.5s ease;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.github-btn:hover {
    transform: scale(1.1);
    background: #0a0a0a;
    border-color: rgba(255, 255, 0, 0.3);
}

.github-btn:active {
    transform: scale(1);
}

.github-btn:hover .icon {
    fill: #ffff00;
    transform: scale(1.1) rotate(360deg);
    filter: drop-shadow(0 0 5px rgba(255, 208, 0, 0.8))
        drop-shadow(0 0 10px rgba(255, 208, 0, 0.6));
}

.github-btn:hover .text {
    filter: drop-shadow(0 0 5px rgba(255, 255, 255, 0.2))
        drop-shadow(0 0 10px rgba(255, 255, 255, 0.4));
}

.text {
    transition: all 1s ease;
}

.icon {
    display: inline-block;
    width: 18px;
    height: 18px;
    margin-top: -3px;
    transition: all 1s ease;
}

@media (max-width: 600px) {
    h1 { font-size: 2.5rem; }
    .game-board { max-width: 300px; }
    .cell { font-size: 2.5rem; }
    .game-info { flex-direction: column; gap: 15px; }
}