@import url('https://fonts.googleapis.com/css2?family=Orbitron:wght@400;500;600;700;800;900&display=swap');

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

body {
    background: linear-gradient(180deg, #0a0a20 0%, #1a0a2e 50%, #0d0d1a 100%);
    min-height: 100vh;
    font-family: 'Orbitron', sans-serif;
    overflow: hidden;
}

/* Back Link */
.back-link {
    position: fixed;
    top: 20px;
    left: 20px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    font-size: 12px;
    font-weight: 500;
    padding: 10px 16px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    transition: all 0.3s ease;
    z-index: 100;
}

.back-link:hover {
    color: #fff;
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(-4px);
}

/* Stars Background */
section {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 40px 20px;
}

section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background:
        radial-gradient(2px 2px at 20px 30px, rgba(255, 255, 255, 0.8), transparent),
        radial-gradient(2px 2px at 40px 70px, rgba(255, 255, 255, 0.5), transparent),
        radial-gradient(1px 1px at 90px 40px, rgba(255, 255, 255, 0.7), transparent),
        radial-gradient(2px 2px at 130px 80px, rgba(255, 255, 255, 0.6), transparent),
        radial-gradient(1px 1px at 160px 120px, rgba(255, 255, 255, 0.8), transparent),
        radial-gradient(2px 2px at 200px 50px, rgba(255, 255, 255, 0.5), transparent),
        radial-gradient(1px 1px at 250px 150px, rgba(255, 255, 255, 0.9), transparent),
        radial-gradient(2px 2px at 300px 100px, rgba(255, 255, 255, 0.4), transparent);
    background-size: 350px 200px;
    animation: twinkle 5s ease-in-out infinite;
    pointer-events: none;
}

@keyframes twinkle {

    0%,
    100% {
        opacity: 1;
    }

    50% {
        opacity: 0.6;
    }
}

/* Solar System Visual */
.visual-solar-system {
    position: relative;
    width: 200px;
    height: 200px;
    margin: 0 auto 40px;
}

.sun {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    width: 40px;
    height: 40px;
    background: radial-gradient(#ffd700, #ff8c00);
    border-radius: 50%;
    box-shadow: 0 0 30px rgba(255, 165, 0, 0.6);
    z-index: 10;
    animation: sunPulse 3s infinite alternate;
}

@keyframes sunPulse {
    from {
        box-shadow: 0 0 20px rgba(255, 165, 0, 0.4);
        transform: translate(-50%, -50%) scale(1);
    }

    to {
        box-shadow: 0 0 40px rgba(255, 165, 0, 0.8);
        transform: translate(-50%, -50%) scale(1.1);
    }
}

.orbit {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    animation: spin linear infinite;
}

.planet {
    position: absolute;
    top: -50%;
    left: 50%;
    transform: translate(-50%, -50%);
    /* Center on orbit */
    border-radius: 50%;
    top: 0;
    /* Align to top of orbit */
}

.mercury-orbit {
    width: 70px;
    height: 70px;
    animation-duration: 4s;
}

.mercury {
    width: 8px;
    height: 8px;
    background: #8b8b8b;
}

.venus-orbit {
    width: 100px;
    height: 100px;
    animation-duration: 7s;
}

.venus {
    width: 12px;
    height: 12px;
    background: #e6e600;
}

.earth-orbit {
    width: 140px;
    height: 140px;
    animation-duration: 10s;
}

.earth {
    width: 14px;
    height: 14px;
    background: #4169e1;
}

.mars-orbit {
    width: 180px;
    height: 180px;
    animation-duration: 15s;
}

.mars {
    width: 10px;
    height: 10px;
    background: #ff4500;
}

@keyframes spin {
    from {
        transform: translate(-50%, -50%) rotate(0deg);
    }

    to {
        transform: translate(-50%, -50%) rotate(360deg);
    }
}

/* Header */
.page-header {
    text-align: center;
    margin-bottom: 30px;
    position: relative;
    z-index: 10;
}

.page-header h1 {
    font-size: 36px;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 10px;
    background: linear-gradient(135deg, #fff, #6366f1, #a855f7);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 5px;
}

.page-header p {
    color: rgba(255, 255, 255, 0.5);
    font-size: 12px;
    letter-spacing: 4px;
    text-transform: uppercase;
}

/* Planet Menu */
ul {
    text-align: center;
    position: relative;
    z-index: 10;
}

ul:hover li a {
    opacity: 0.3;
}

ul li {
    list-style: none;
    margin: 16px 0;
    position: relative;
}

ul li a {
    color: white;
    text-decoration: none;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 6px;
    padding: 12px 25px;
    border-radius: 30px;
    display: inline-block;
    min-width: 160px;
    transition: all 0.4s ease;
    text-transform: uppercase;
    position: relative;
    z-index: 100;
    border: 2px solid transparent;
}

/* Planet Colors */
ul li:nth-child(1) a {
    background: linear-gradient(135deg, #ffd700, #ff8c00);
    box-shadow: 0 5px 30px rgba(255, 215, 0, 0.3);
}

ul li:nth-child(2) a {
    background: linear-gradient(135deg, #8b8b8b, #5a5a5a);
    box-shadow: 0 5px 30px rgba(139, 139, 139, 0.3);
}

ul li:nth-child(3) a {
    background: linear-gradient(135deg, #e6b800, #cc9900);
    box-shadow: 0 5px 30px rgba(230, 184, 0, 0.3);
}

ul li:nth-child(4) a {
    background: linear-gradient(135deg, #4169e1, #1e90ff);
    box-shadow: 0 5px 30px rgba(65, 105, 225, 0.3);
}

ul li:nth-child(5) a {
    background: linear-gradient(135deg, #ff4500, #ff6347);
    box-shadow: 0 5px 30px rgba(255, 69, 0, 0.3);
}

ul li:nth-child(6) a {
    background: linear-gradient(135deg, #daa520, #b8860b);
    box-shadow: 0 5px 30px rgba(218, 165, 32, 0.3);
}

ul li:nth-child(7) a {
    background: linear-gradient(135deg, #40e0d0, #00ced1);
    box-shadow: 0 5px 30px rgba(64, 224, 208, 0.3);
}

ul li:nth-child(8) a {
    background: linear-gradient(135deg, #4169e1, #0000cd);
    box-shadow: 0 5px 30px rgba(65, 105, 225, 0.3);
}

ul li a:hover {
    transform: scale(1.3);
    opacity: 1 !important;
    border-color: rgba(255, 255, 255, 0.5);
}

/* Sun glow effect */
ul li:nth-child(1) a:hover {
    box-shadow: 0 0 60px rgba(255, 215, 0, 0.8);
}

ul li:nth-child(2) a:hover {
    box-shadow: 0 0 60px rgba(139, 139, 139, 0.8);
}

ul li:nth-child(3) a:hover {
    box-shadow: 0 0 60px rgba(230, 184, 0, 0.8);
}

ul li:nth-child(4) a:hover {
    box-shadow: 0 0 60px rgba(65, 105, 225, 0.8);
}

ul li:nth-child(5) a:hover {
    box-shadow: 0 0 60px rgba(255, 69, 0, 0.8);
}

ul li:nth-child(6) a:hover {
    box-shadow: 0 0 60px rgba(218, 165, 32, 0.8);
}

ul li:nth-child(7) a:hover {
    box-shadow: 0 0 60px rgba(64, 224, 208, 0.8);
}

ul li:nth-child(8) a:hover {
    box-shadow: 0 0 60px rgba(65, 105, 225, 0.8);
}

/* Large Text Effect */
ul li::after {
    content: attr(data-text);
    color: white;
    position: fixed;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);
    font-size: 120px;
    font-weight: 900;
    text-transform: uppercase;
    opacity: 0;
    pointer-events: none;
    letter-spacing: 80px;
    transition: all 0.5s ease;
    z-index: 1;
}

ul li:hover::after {
    opacity: 0.1;
    letter-spacing: 30px;
}

/* Footer */
footer {
    position: fixed;
    bottom: 20px;
    left: 0;
    right: 0;
    text-align: center;
    color: rgba(255, 255, 255, 0.3);
    font-size: 11px;
    letter-spacing: 2px;
}

/* Responsive */
@media (max-width: 768px) {
    .back-link {
        top: 10px;
        left: 10px;
        padding: 8px 12px;
        font-size: 10px;
    }

    .page-header h1 {
        font-size: 28px;
        letter-spacing: 8px;
    }

    ul li a {
        font-size: 12px;
        min-width: 140px;
        padding: 10px 20px;
        letter-spacing: 4px;
    }

    ul li::after {
        font-size: 60px;
        letter-spacing: 30px;
    }

    ul li:hover::after {
        letter-spacing: 10px;
    }
}