/* causality.club - Cyberpunk Causal Chain Traversal */

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

:root{
    --void:#0A0E17;
    --steel:#1B2838;
    --cyan:#00F0FF;
    --magenta:#FF2E63;
    --white:#C8D6E5;
    --ghost:#8B9BB4;
    --gold:#F7B731;
}

html{scroll-behavior:smooth}

body{
    background:var(--void);
    color:var(--white);
    font-family:'Exo 2',sans-serif;
    font-weight:300;
    font-size:clamp(0.875rem,1.2vw,1.1rem);
    line-height:1.75;
    letter-spacing:0.02em;
    overflow-x:hidden;
}

.svg-defs{position:absolute;width:0;height:0;overflow:hidden}

/* Interference pattern */
.interference{
    position:fixed;
    inset:0;
    z-index:0;
    pointer-events:none;
    background:
        repeating-linear-gradient(87deg,transparent,transparent 2px,rgba(0,240,255,0.03) 2px,rgba(0,240,255,0.03) 3px),
        repeating-linear-gradient(93deg,transparent,transparent 2px,rgba(0,240,255,0.03) 2px,rgba(0,240,255,0.03) 3px);
}

/* HUD overlay */
.hud{
    position:fixed;
    inset:0;
    z-index:100;
    pointer-events:none;
}

.hud-bracket{
    position:absolute;
    width:40px;height:40px;
    opacity:0.7;
}

.hud-tl{top:12px;left:12px}
.hud-tr{top:12px;right:12px}
.hud-bl{bottom:12px;left:12px}
.hud-br{bottom:12px;right:12px}

.hud-depth{
    position:absolute;
    top:20px;left:60px;
    font-family:'Fira Code',monospace;
    font-size:0.75rem;
    letter-spacing:0.08em;
    color:var(--cyan);
    opacity:0.7;
    text-transform:uppercase;
}

.hud-progress{
    position:absolute;
    top:0;right:0;bottom:0;
    width:2px;
    background:var(--void);
}

.hud-progress-fill{
    width:100%;
    height:0%;
    background:var(--magenta);
    transition:height 100ms linear;
}

/* Particle canvas */
.particle-canvas{
    position:fixed;
    inset:0;
    z-index:2;
    pointer-events:none;
}

/* Nodes */
.node{
    min-height:100vh;
    position:relative;
    z-index:5;
    display:flex;
    flex-direction:column;
    align-items:center;
    justify-content:center;
    padding:clamp(40px,8vh,80px) clamp(24px,6vw,80px);
}

.node-circle{
    position:absolute;
    width:clamp(200px,40vmin,400px);
    height:clamp(200px,40vmin,400px);
    border-radius:50%;
    border:2px solid var(--cyan);
    opacity:0;
    transform:scale(0.8);
    transition:opacity 800ms ease,transform 800ms ease;
}

.node-circle.drawn{
    opacity:0.15;
    transform:scale(1);
}

.node-content{
    position:relative;
    z-index:2;
    text-align:center;
    max-width:600px;
}

/* Reveal animation */
.reveal-node{
    opacity:0;
    transform:translateY(20px);
    transition:opacity 500ms cubic-bezier(0.22,1,0.36,1),transform 500ms cubic-bezier(0.22,1,0.36,1);
}

.reveal-node.visible{
    opacity:1;
    transform:translateY(0);
}

.node-heading{
    font-family:'Share Tech Mono',monospace;
    font-size:clamp(1.2rem,3vw,2.8rem);
    letter-spacing:0.12em;
    text-transform:uppercase;
    color:var(--white);
    margin-bottom:1rem;
}

.node-body{
    color:var(--ghost);
    max-width:45ch;
    margin:0 auto;
}

.causal-notation{
    display:block;
    margin-top:1rem;
    font-family:'Fira Code',monospace;
    font-size:0.75rem;
    letter-spacing:0.08em;
    color:var(--cyan);
    opacity:0.7;
}

/* Hero */
.hero-title{
    font-family:'Share Tech Mono',monospace;
    font-size:clamp(2rem,8vw,10rem);
    letter-spacing:0.12em;
    text-transform:uppercase;
    color:var(--white);
    line-height:0.95;
    white-space:nowrap;
    overflow:hidden;
    min-height:1.2em;
}

.hero-title .line{
    display:block;
}

.hero-title .line-club{
    font-size:0.4em;
    color:var(--magenta);
    text-align:right;
    margin-top:0.2em;
}

.hero-title .hchar{
    display:inline-block;
    opacity:0;
}

.hero-title .hchar.show{
    opacity:1;
}

.hero-sub{
    font-family:'Fira Code',monospace;
    font-size:0.75rem;
    letter-spacing:0.08em;
    color:var(--cyan);
    opacity:0.7;
    margin-top:2rem;
    text-transform:uppercase;
}

.origin-label,.terminus-label{
    position:absolute;
    font-family:'Fira Code',monospace;
    font-size:0.65rem;
    letter-spacing:0.12em;
    color:var(--ghost);
    opacity:0.5;
    text-transform:uppercase;
}

.origin-label{top:20px}
.terminus-label{bottom:20px}

/* Edge lines between nodes */
.edge-line{
    width:2px;
    height:clamp(60px,10vh,120px);
    margin:0 auto;
    position:relative;
    z-index:5;
    background:linear-gradient(to bottom,var(--cyan),transparent);
    opacity:0.3;
    animation:edgePulse 2s ease-in-out infinite;
}

@keyframes edgePulse{
    0%,100%{opacity:0.2}
    50%{opacity:0.5}
}

/* Return button */
.return-btn{
    display:flex;
    align-items:center;
    justify-content:center;
    margin:2rem auto 0;
    background:none;
    border:none;
    cursor:pointer;
    animation:returnPulse 2s ease-in-out infinite;
    transition:transform 200ms ease;
}

.return-btn:hover{
    transform:scale(1.15);
}

@keyframes returnPulse{
    0%,100%{opacity:0.7;transform:scale(1)}
    50%{opacity:1;transform:scale(1.08)}
}

/* Responsive */
@media(max-width:768px){
    .hud-bracket{width:24px;height:24px}
    .hud-depth{left:44px;font-size:0.6rem}

    .node-heading{
        font-size:clamp(1rem,5vw,1.8rem);
    }

    .hero-title{
        font-size:clamp(1.5rem,6vw,4rem);
    }
}