:root {
    --bg-color: #05050f;
    --text-primary: #e0e6ed;
    --text-secondary: #a0aec0;
    --neon-blue: #00f3ff;
    --neon-purple: #bc13fe;
    --glass-bg: rgba(16, 20, 36, 0.6);
    --glass-border: rgba(0, 243, 255, 0.2);
    --box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

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

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: 'Roboto', sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    position: relative;
}

/* Background effects */
.stars, .twinkling {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.stars {
    background: transparent url('data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSI0MDAiIGhlaWdodD0iNDAwIj48cmVjdCB3aWR0aD0iNDAwIiBoZWlnaHQ9IjQwMCIgZmlsbD0iIzAwMCIvPjxjaXJjbGUgY3g9IjEwMCIgY3k9IjEwMCIgcj0iMSIgZmlsbD0iI2ZmZiIvPjxjaXJjbGUgY3g9IjMwMCIgY3k9IjIwMCIgcj0iMC41IiBmaWxsPSIjZmZmIi8+PGNpcmNsZSBjeD0iMjUwIiBjeT0iMzUwIiByPSIxLjUiIGZpbGw9IiNmZmIiLz48L3N2Zz4=') repeat;
}

.glass-header, .glass-footer {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--glass-border);
    padding: 1.5rem;
    text-align: center;
}

.glass-header h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 2rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    background: linear-gradient(90deg, var(--neon-blue), var(--neon-purple));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-shadow: 0 0 10px rgba(0, 243, 255, 0.3);
}

.container {
    flex: 1;
    max-width: 800px;
    margin: 2rem auto;
    padding: 0 1rem;
    width: 100%;
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.glass-panel {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2rem;
    box-shadow: var(--box-shadow);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.glass-panel:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 40px 0 rgba(0, 243, 255, 0.1);
    border-color: rgba(0, 243, 255, 0.4);
}

.hidden {
    display: none !important;
}

/* Form Controls */
.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

label {
    font-family: 'Orbitron', sans-serif;
    font-size: 0.9rem;
    color: var(--neon-blue);
    letter-spacing: 1px;
}

select, input {
    width: 100%;
    padding: 1rem;
    background: rgba(0, 0, 0, 0.5);
    border: 1px solid rgba(0, 243, 255, 0.3);
    border-radius: 8px;
    color: white;
    font-size: 1.1rem;
    font-family: 'Roboto', sans-serif;
    outline: none;
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

select:focus, input:focus {
    border-color: var(--neon-blue);
    box-shadow: 0 0 15px rgba(0, 243, 255, 0.3);
}

select option {
    background: #101424;
    color: white;
}

.loading {
    margin-top: 1rem;
    color: var(--neon-purple);
    font-style: italic;
    text-align: center;
    animation: pulse 1.5s infinite;
}

.error {
    margin-top: 1rem;
    color: #ff3366;
    text-align: center;
}

/* Data Card */
.data-card h2 {
    font-family: 'Orbitron', sans-serif;
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: var(--text-primary);
}

.glow-text {
    text-shadow: 0 0 15px rgba(0, 243, 255, 0.5);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.5rem;
}

.stat-item {
    background: rgba(0, 0, 0, 0.4);
    padding: 1.5rem;
    border-radius: 12px;
    border-left: 3px solid var(--neon-purple);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--neon-blue);
}

/* Calculator */
.calculator-section h3 {
    font-family: 'Orbitron', sans-serif;
    margin-bottom: 1.5rem;
    color: var(--text-primary);
    text-align: center;
}

.calc-result {
    margin-top: 2rem;
    text-align: center;
    background: rgba(0, 0, 0, 0.4);
    padding: 1.5rem;
    border-radius: 12px;
    border-top: 3px solid var(--neon-blue);
}

.calc-result h4 {
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: normal;
}

.weight-display {
    font-family: 'Orbitron', sans-serif;
    font-size: 3rem;
    color: var(--neon-blue);
}

.glass-footer {
    border-bottom: none;
    border-top: 1px solid var(--glass-border);
    margin-top: auto;
}

.glass-footer p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.glass-footer a {
    color: var(--neon-blue);
    text-decoration: none;
    transition: color 0.3s ease;
}

.glass-footer a:hover {
    color: var(--neon-purple);
}

@keyframes pulse {
    0% { opacity: 0.6; }
    50% { opacity: 1; }
    100% { opacity: 0.6; }
}

@media (max-width: 600px) {
    .glass-header h1 {
        font-size: 1.5rem;
    }
    
    .data-card h2 {
        font-size: 2rem;
    }
    
    .glass-panel {
        padding: 1.5rem;
    }
}