:root {
    --linen-bg: #f8f9fa;
    --crystal-white: rgba(255, 255, 255, 0.8);
    --anchor-gray: #4a4a4a;
    --spectrum-blue: #007bff;
    --soft-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.15);
}

body {
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--linen-bg);
    color: var(--anchor-gray);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    align-items: center;
}

header {
    width: 100%;
    padding: 2rem 0;
    text-align: center;
    background: var(--crystal-white);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.18);
    box-shadow: var(--soft-shadow);
}

h1 {
    font-weight: 300;
    letter-spacing: 2px;
    margin-bottom: 1rem;
}

nav .prism-toggle {
    background: transparent;
    border: 1px solid var(--anchor-gray);
    padding: 0.5rem 1rem;
    cursor: pointer;
    margin: 0 5px;
    border-radius: 20px;
    transition: all 0.3s ease;
}

nav .prism-toggle:hover {
    background: var(--anchor-gray);
    color: white;
}

main {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 90%;
    max-width: 600px;
}

.crystalline-card {
    background: var(--crystal-white);
    backdrop-filter: blur(8px);
    border-radius: 15px;
    padding: 2.5rem;
    box-shadow: var(--soft-shadow);
    border: 1px solid rgba(255, 255, 255, 0.4);
    text-align: center;
    min-height: 150px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#refraction-display {
font-size: 1.2rem;
line-height: 1.6;
font-style: italic;
transition: opacity 0.3s ease;
}

.controls {
    margin-top: 2rem;
}

button[onclick] {
    background: var(--anchor-gray);
    color: white;
    border: none;
    padding: 1rem 2rem;
    font-size: 1rem;
    border-radius: 30px;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
    transition: transform 0.2s ease;
    margin: 10px;
}

button[onclick]:hover {
    transform: translateY(-2px);
}

footer {
    padding: 2rem;
    font-size: 0.8rem;
    opacity: 0.6;
}