body {
    margin: 0;
    height: 100vh;
    background-color: #000000;
    background: 
        /* En üstteki ince gürültü (noise) efekti profesyonellik katar */
        radial-gradient(circle at 80% 20%, rgba(255, 0, 0, 0.15) 0%, transparent 40%),
        /* Keskin çapraz çizgiler */
        linear-gradient(135deg, #000000 0%, #0a0a0a 45%, #220000 50%, #0a0a0a 55%, #000000 100%);
    background-size: cover;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

/* Opsiyonel: Kayan bir çizgi animasyonu eklemek istersen */
body::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: linear-gradient(transparent, rgba(255, 0, 0, 0.1), transparent);
    transform: rotate(45deg);
    animation: shine 8s infinite linear;
    pointer-events: none;
}

@keyframes shine {
    0% { transform: translateY(-100%) rotate(45deg); }
    100% { transform: translateY(100%) rotate(45deg); }
}

.dark-mode {
    background-color: rgba(0,0,0,255);
    color: #f4f4f4;
    font-family: Verdana, Sans-Serif;
}
.dark-mode button {
    color: #f4f4f4;
}
.light-mode {
    background-color: #f4f4f4;
    color: rgba(0,0,0,255);
    font-family: Verdana, Sans-Serif;
}
.light-mode button {
    color: rgba(0,0,0,255);
}