/* relativity.quest - Sci-Fi Spacetime Observatory */
* { margin: 0; padding: 0; box-sizing: border-box; }
:root {
    --deep-space: #060614;
    --space-mid: #101030;
    --cosmic-blue: #3040A0;
    --hawking-gold: #FFD700;
    --redshift: #FF4444;
    --blueshift: #00B4D8;
    --starlight: #F0F0FA;
    --nebula-gray: #7080A0;
}
body {
    background: var(--deep-space);
    color: var(--starlight);
    font-family: 'Exo 2', sans-serif;
    font-weight: 400;
    overflow-x: hidden;
}

/* Spacetime Grid */
#spacetime-grid {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
    pointer-events: none;
    background:
        repeating-linear-gradient(90deg, rgba(48,64,160,0.08) 0px, transparent 1px, transparent 40px),
        repeating-linear-gradient(0deg, rgba(48,64,160,0.08) 0px, transparent 1px, transparent 40px);
}

/* Time Dilation Clock */
#time-clock {
    position: fixed;
    top: 1.5rem;
    right: 1.5rem;
    z-index: 10;
    font-family: 'Fira Code', monospace;
    font-size: 0.85rem;
    color: var(--hawking-gold);
    opacity: 0.6;
}
.clock-label { opacity: 0.5; }

/* Sections */
.section {
    position: relative;
    z-index: 1;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 4rem 2rem;
}
.section-content {
    max-width: 620px;
    text-align: center;
    background: rgba(6,6,20,0.8);
    border: 1px solid rgba(48,64,160,0.2);
    padding: 3rem;
    border-radius: 4px;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s ease, transform 0.8s ease;
    box-shadow: 0 0 60px rgba(48,64,160,0.08);
}
.section-content.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Light Cones */
.light-cone {
    width: 0;
    height: 0;
    position: relative;
    z-index: 0;
}
.top-cone {
    border-left: 60px solid transparent;
    border-right: 60px solid transparent;
    border-bottom: 80px solid rgba(255,215,0,0.06);
    margin-bottom: 2rem;
}
.bottom-cone {
    border-left: 60px solid transparent;
    border-right: 60px solid transparent;
    border-top: 80px solid rgba(255,215,0,0.06);
    margin-top: 2rem;
}

/* Typography */
.display-title {
    font-size: clamp(2rem, 5vw, 4rem);
    font-weight: 700;
    color: var(--hawking-gold);
    letter-spacing: 0.02em;
    text-shadow: 0 0 40px rgba(255,215,0,0.2);
}
.equation {
    font-family: 'Fira Code', monospace;
    font-size: 1.2rem;
    color: var(--blueshift);
    margin-top: 1rem;
    opacity: 0.8;
}
.hero-sub {
    font-size: 1rem;
    color: var(--nebula-gray);
    margin-top: 0.75rem;
    font-style: italic;
}
.section-title {
    font-size: clamp(1.5rem, 3.5vw, 2.5rem);
    font-weight: 700;
    color: var(--hawking-gold);
    margin-bottom: 1.5rem;
}
.section-body {
    font-size: 1rem;
    line-height: 1.75;
    color: var(--starlight);
    opacity: 0.85;
}
.data-note {
    font-family: 'Fira Code', monospace;
    font-size: 0.9rem;
    color: var(--blueshift);
    margin-top: 1.5rem;
    opacity: 0.5;
}

/* Section-specific glow */
#hero .section-content { border-color: rgba(255,215,0,0.15); }
#spacetime .section-content { border-color: rgba(0,180,216,0.15); }
#dilation .section-content { border-color: rgba(255,68,68,0.15); }
#lensing .section-content { border-color: rgba(48,64,160,0.25); }
#horizon .section-content { border-color: rgba(255,68,68,0.2); background: rgba(6,6,20,0.9); }

/* Footer */
#footer {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: 4rem 2rem;
}
.footer-text {
    font-size: 0.8rem;
    color: var(--nebula-gray);
    opacity: 0.3;
}

@media (max-width: 600px) {
    .section { padding: 3rem 1.5rem; }
    .section-content { padding: 2rem 1.5rem; }
    .light-cone { border-left-width: 40px; border-right-width: 40px; }
    .top-cone { border-bottom-width: 55px; }
    .bottom-cone { border-top-width: 55px; }
}