* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --win11-primary: #667eea;
    --win11-secondary: #764ba2;
    --win11-accent: #8a2be2;
    --win11-background: #f5f5f7;
    --win11-card-bg: rgba(255, 255, 255, 0.85);
    --win11-text: #1f1f1f;
    --win11-text-secondary: #666666;
    --win11-border: rgba(102, 126, 234, 0.1);
    --win11-shadow: 0 8px 32px rgba(102, 126, 234, 0.1);
    --win11-radius: 16px;
    --win11-input-radius: 12px;
    --win11-btn-radius: 12px;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: var(--win11-text);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
    position: relative;
    overflow: hidden;
}

/* 星空背景 */
.stars {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #0a0a23 0%, #1a1a40 50%, #0a0a23 100%);
    z-index: -2;
}

.star {
    position: absolute;
    background: white;
    border-radius: 50%;
    animation: twinkle 3s infinite ease-in-out;
}

@keyframes twinkle {
    0%, 100% { opacity: 0.3; }
    50% { opacity: 1; }
}

/* 星云效果 */
.nebula {
    position: absolute;
    border-radius: 50%;
    filter: blur(50px);
    z-index: -1;
}

.nebula:nth-child(1) {
    top: 20%;
    left: 10%;
    width: 300px;
    height: 300px;
    background: rgba(102, 126, 234, 0.3);
}

.nebula:nth-child(2) {
    bottom: 10%;
    right: 15%;
    width: 400px;
    height: 400px;
    background: rgba(118, 75, 162, 0.2);
}

.win11-404-card {
    background: var(--win11-card-bg);
    border-radius: var(--win11-radius);
    box-shadow: var(--win11-shadow);
    backdrop-filter: blur(20px);
    border: 1px solid var(--win11-border);
    overflow: hidden;
    transition: all 0.3s ease;
    max-width: 600px;
    width: 100%;
    text-align: center;
    padding: 4rem;
    animation: slideUp 0.8s ease;
}

.win11-404-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(102, 126, 234, 0.15);
}

.win11-404-header {
    margin-bottom: 3rem;
}

.win11-404-header h1 {
    color: var(--win11-primary);
    margin-bottom: 1rem;
    font-size: 6rem;
    font-weight: 700;
    letter-spacing: -2px;
    text-shadow: 0 4px 8px rgba(102, 126, 234, 0.3);
}

.win11-404-header h2 {
    color: var(--win11-primary);
    margin-bottom: 1.5rem;
    font-size: 2rem;
    font-weight: 600;
}

.subtitle {
    color: var(--win11-text-secondary);
    margin-bottom: 3rem;
    font-size: 1.2rem;
    font-weight: 400;
    line-height: 1.6;
}

.win11-btn {
    display: inline-block;
    padding: 1.25rem 2.5rem;
    background: linear-gradient(135deg, var(--win11-primary) 0%, var(--win11-secondary) 100%);
    color: white;
    border: none;
    border-radius: var(--win11-btn-radius);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.win11-btn::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.win11-btn:hover::before {
    left: 100%;
}

.win11-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 24px rgba(102, 126, 234, 0.3);
}

.win11-btn:active {
    transform: translateY(0);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.2);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.home-link {
    display: block;
    margin-top: 2rem;
    color: var(--win11-text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.3s ease;
}

.home-link:hover {
    color: var(--win11-primary);
    text-decoration: underline;
}

@media (max-width: 768px) {
    body {
        padding: 1rem;
    }
    
    .win11-404-card {
        padding: 2.5rem;
    }
    
    .win11-404-header h1 {
        font-size: 4rem;
    }
    
    .win11-404-header h2 {
        font-size: 1.5rem;
    }
    
    .subtitle {
        font-size: 1rem;
    }
    
    .win11-btn {
        padding: 1.125rem 2rem;
    }
}