/* Basic style */
:root {
    --primary-color: #0a0e17;
    --secondary-color: #1a1f2e;
    --accent-blue: #00d9ff;
    --accent-purple: #9d4edd;
    --accent-green: #4ade80;
    --text-color: #e2e8f0;
    --pixel-size: 4px;
    --border-radius: 8px;
    --transition-speed: 0.3s;
}

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

body {
    background-color: var(--primary-color);
    color: var(--text-color);
    line-height: 1.6;
    overflow-x: hidden;
    position: relative;
}

#app {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    position: relative;
    z-index: 2;
}

/* General style */
.section {
    background-color: rgba(26, 31, 46, 0.6);
    border-radius: var(--border-radius);
    padding: 2rem;
    margin-bottom: 2rem;
    transition: transform var(--transition-speed);
    position: relative;
    z-index: 1;
    backdrop-filter: blur(5px);
}

.section:hover {
    transform: translateY(-2px);
}

.section-title {
    font-size: 1.8rem;
    margin-bottom: 1.5rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--accent-blue);
    display: inline-block;
}

/* Grid system */
.grid-1 { display: grid; grid-template-columns: 1fr; gap: 1.5rem; }
.grid-2 { display: grid; grid-template-columns: repeat(auto-fit, minmax(300px, 1fr)); gap: 1.5rem; }
.grid-3 { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.5rem; }

/* Tools */
.flex-center { display: flex; justify-content: center; align-items: center; }
.flex-column { display: flex; flex-direction: column; }
.text-center { text-align: center; }
.gap-1 { gap: 1rem; }
.gap-2 { gap: 1.5rem; }
.mt-1 { margin-top: 1rem; }
.mt-2 { margin-top: 1.5rem; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 1.5rem; }

/* Snowflake decoration */
.pixel-decoration {
    position: fixed;
    width: 6px;
    height: 6px;
    background: linear-gradient(135deg, var(--accent-blue), white);
    border-radius: 50%;
    z-index: 9999; /* Top */
    opacity: 0.6;
    pointer-events: none;
    filter: blur(0.5px);
}

/* Snow size */
.pixel-decoration:nth-child(odd) {
    width: 8px;
    height: 8px;
    filter: blur(1px);
    background: white;
}

.pixel-decoration:nth-child(3n) {
    width: 4px;
    height: 4px;
    filter: blur(0.3px);
    background: var(--accent-blue);
    opacity: 0.4;
}

/* Snow fall */
@keyframes snowfall {
    0% {
        transform: translateY(-100px) translateX(0) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.7;
    }
    90% {
        opacity: 0.3;
    }
    100% {
        transform: translateY(100vh) translateX(100px) rotate(360deg);
        opacity: 0;
    }
}

@keyframes snowfall2 {
    0% {
        transform: translateY(-100px) translateX(50px) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.5;
    }
    90% {
        opacity: 0.2;
    }
    100% {
        transform: translateY(100vh) translateX(-50px) rotate(-360deg);
        opacity: 0;
    }
}

@keyframes snowfall3 {
    0% {
        transform: translateY(-100px) translateX(-30px) rotate(0deg);
        opacity: 0;
    }
    10% {
        opacity: 0.6;
    }
    90% {
        opacity: 0.1;
    }
    100% {
        transform: translateY(100vh) translateX(30px) rotate(180deg);
        opacity: 0;
    }
}

.pixel-decoration:nth-child(4n) {
    animation: snowfall 12s linear infinite;
}

.pixel-decoration:nth-child(4n+1) {
    animation: snowfall2 15s linear infinite;
    animation-delay: 1s;
}

.pixel-decoration:nth-child(4n+2) {
    animation: snowfall3 10s linear infinite;
    animation-delay: 2s;
}

.pixel-decoration:nth-child(4n+3) {
    animation: snowfall 8s linear infinite;
    animation-delay: 3s;
}

/* Responsive design */
@media (max-width: 768px) {
    .section {
        padding: 1.5rem;
    }
    
    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
    }

    .pixel-decoration {
        display: none;
    }
    
    .pixel-decoration:nth-child(-n+20) {
        display: block;
    }
}