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

body {
    font-family: 'Orbitron', sans-serif;
    background: #000000;
    overflow: hidden;
    width: 100vw;
    height: 100vh;
    color: white;
}

.container {
    position: relative;
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    align-items: center;
    padding: 50px;
}

.title {
    font-size: 3rem;
    font-weight: 900;
    text-transform: uppercase;
    letter-spacing: 10px;
    z-index: 10;
    transition: all 4s ease;
}

.title.hidden {
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
}

/* Singularity - 5px white dot */
.singularity {
    position: absolute;
    width: 5px;
    height: 5px;
    background: #ffffff;
    border-radius: 50%;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    box-shadow: 0 0 10px #ffffff;
    z-index: 5;
    transition: transform 0.5s ease-in, opacity 0.5s;
}

.singularity.hidden {
    opacity: 0;
}

/* Start Button */
.start-button {
    padding: 15px 50px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.2rem;
    font-weight: 700;
    color: #000000;
    background: white;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 4s ease;
    text-transform: uppercase;
    letter-spacing: 2px;
    z-index: 10;
}

.start-button:hover {
    background: #eeeeee;
    transform: scale(1.05);
}

.start-button.hidden {
    opacity: 0;
    pointer-events: none;
    visibility: hidden;
    transform: scale(0.8);
}

/* Particles */
.particles {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 1;
}

.particle {
    position: absolute;
    border-radius: 50%;
    background: white;
    will-change: transform;
}

.particle.yellow {
    background: #ffff00;
    box-shadow: 0 0 5px #ffff00;
}

.particle.white {
    background: #ffffff;
    box-shadow: 0 0 5px #ffffff;
}

.particle.fading-out {
    opacity: 0 !important;
    transition: opacity 2s ease;
}

/* Navigation Buttons (Urknalltheorie etc.) */
.nav-button {
    position: absolute;
    left: 40px;
    top: 30vh;
    /* Mitte des 2. Segments (20vh bis 40vh) */
    transform: translateY(-50%);
    padding: 18px 38px;
    background: rgba(255, 255, 255, 0.1);
    color: white;
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 4px;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.35rem;
    cursor: pointer;
    transition: all 2s ease;
    z-index: 20;
    backdrop-filter: blur(5px);
    opacity: 1;
    visibility: visible;
}

.nav-button:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: white;
    box-shadow: 0 0 15px rgba(255, 255, 255, 0.2);
}

.nav-button.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-50%) translateX(-20px);
}

/* Info Label & Line */
.info-label {
    position: absolute;
    left: 40px;
    top: 10vh;
    /* Mitte des 1. Segments (0vh bis 20vh) */
    transform: translateY(-50%);
    font-size: 1.5rem;
    font-weight: 400;
    letter-spacing: 5px;
    text-transform: uppercase;
    color: white;
    transition: opacity 2s ease;
    z-index: 15;
}

.info-line-svg {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 14;
}

.info-line {
    stroke: white;
    stroke-width: 1;
    opacity: 0.6;
    transition: opacity 2s ease;
}

.info-label.hidden,
.info-line.hidden,
.description-text.hidden,
.time-box.hidden,
#startInfoBox.hidden,
#tempInfoBox.hidden {
    opacity: 0;
}

.description-text {
    position: absolute;
    left: 75%;
    /* Exakt in der Mitte zwischen 50% (Punkt) und 100% (Rand) */
    top: 50%;
    transform: translate(-50%, -50%);
    width: 320px;
    font-size: 1rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.8);
    transition: opacity 2s ease;
    z-index: 15;
    text-align: center;
    /* Zentrierter Text innerhalb der Box sieht bei dieser Position oft besser aus */
}

.time-box {
    position: absolute;
    bottom: 75px;
    /* User request: 75px from bottom */
    left: 50%;
    transform: translateX(-50%);
    width: 85%;
    max-width: 1000px;
    height: 30px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.15);
    display: flex;
    justify-content: center;
    align-items: center;
    color: white;
    font-size: 0.85rem;
    letter-spacing: 2px;
    text-transform: uppercase;
    transition: opacity 2s ease;
    z-index: 10;
}

.premium-box {
    background: rgba(0, 0, 0, 0.6);
    /* Dunklerer Hintergrund für Lesbarkeit */
    backdrop-filter: blur(15px);
    /* Stärkerer Blur */
    border: 1px solid rgba(255, 255, 255, 0.4);
    box-shadow: 0 0 30px rgba(255, 255, 255, 0.1);
    font-weight: 700;
}

.temperature-box {
    bottom: calc(75px + 40px);
    /* 75px + spacing */
}

/* Burning/Fire Effect for Particles */
.particle.fire {
    background: #ff4500 !important;
    /* Orangered */
    box-shadow: 0 0 8px #ff4500; /* Reduced shadow for performance */
    transition: background 2s ease, box-shadow 2s ease;
}