/* ==========================================================
   alth.ing  —  A monument to the Icelandic Althing.
   Dark-academia gravitas, Scandinavian austerity.
   ========================================================== */

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

:root {
    /* Palette from DESIGN.md */
    --volcanic-night:  #0d1117;   /* primary background */
    --obsidian:        #161b22;   /* surface */
    --basalt-gray:     #484f58;   /* muted, borders, rift */
    --arctic-silver:   #c9d1d9;   /* secondary text */
    --snow-white:      #e6edf3;   /* primary text */
    --glacier-blue:    #4a90d9;   /* accent */
    --manuscript-gold: #d4a84b;   /* warm accent */
    --lava-umber:      #6b4423;   /* hover earth */
    --aurora-green:    #2d8659;   /* aurora secondary */
    --aurora-violet:   #8b5cf6;   /* aurora tertiary */

    --reading-col: 680px;
    --rift-x: 48vw;

    --ease-geo: cubic-bezier(0.25, 0.1, 0.25, 1.0);
}

html { scroll-behavior: smooth; }

body {
    background: var(--volcanic-night);
    color: var(--snow-white);
    font-family: 'Lora', Georgia, serif;
    font-size: 1.1rem;
    line-height: 1.9;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    position: relative;
    min-height: 100vh;
}

/* Vellum noise texture overlay - covers everything subtly */
.vellum-overlay {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 1;
    opacity: 0.55;
    mix-blend-mode: overlay;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='220' height='220'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' seed='7'/><feColorMatrix values='0 0 0 0 0.85   0 0 0 0 0.82   0 0 0 0 0.74   0 0 0 0.04 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

.vellum-defs { position: absolute; width: 0; height: 0; }

/* ----------------------------------------------------------
   Tectonic Rift Spine
   ---------------------------------------------------------- */
.rift-spine {
    position: fixed;
    top: 0;
    left: var(--rift-x);
    width: 2px;
    height: 100vh;
    pointer-events: none;
    z-index: 2;
    transform: translateX(-50%);
}

.rift-svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

.rift-svg path {
    stroke-dasharray: 1;
    stroke-dashoffset: 1;
    transition: stroke 1200ms var(--ease-geo);
}

.rift-spine.alive .rift-svg path {
    stroke: var(--basalt-gray);
}

.rift-spine.gold .rift-svg path {
    stroke: var(--manuscript-gold);
}

/* ----------------------------------------------------------
   Aurora flash — transient luminous edge
   ---------------------------------------------------------- */
.aurora-flash {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--glacier-blue) 25%,
        var(--aurora-green) 50%,
        var(--aurora-violet) 75%,
        transparent 100%);
    opacity: 0;
    z-index: 100;
    pointer-events: none;
    transition: opacity 1500ms var(--ease-geo);
    filter: blur(0.5px);
}

.aurora-flash.flash {
    opacity: 0.85;
    transition: opacity 200ms ease-in;
}

/* ----------------------------------------------------------
   "Enter the Assembly" link — sole top affordance
   ---------------------------------------------------------- */
.enter-link {
    position: fixed;
    top: 28px;
    left: 50%;
    transform: translateX(-50%);
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
    font-size: 0.75rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--basalt-gray);
    text-decoration: none;
    z-index: 50;
    transition: color 800ms var(--ease-geo), opacity 1200ms var(--ease-geo);
    border-bottom: 1px solid transparent;
    padding-bottom: 4px;
}

.enter-link:hover {
    color: var(--manuscript-gold);
    border-bottom-color: var(--manuscript-gold);
}

.enter-link.faded { opacity: 0.18; }

/* ----------------------------------------------------------
   HERO — The Law Rock
   ---------------------------------------------------------- */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    position: relative;
    z-index: 3;
    padding: 0 5vw;
}

.hero-inner {
    width: 100%;
    max-width: 1100px;
    text-align: center;
    position: relative;
}

.hero-mark {
    width: 100%;
    height: auto;
    max-height: 40vh;
    opacity: 0;
    animation: heroFade 2400ms var(--ease-geo) 600ms forwards;
}

.hero-mark text {
    paint-order: stroke fill;
}

.hero-rift {
    width: 100%;
    height: 6px;
    margin-top: 3.5rem;
    display: block;
}

#heroRiftLine {
    transition: x1 3000ms var(--ease-geo) 1400ms,
                x2 3000ms var(--ease-geo) 1400ms,
                stroke 1200ms var(--ease-geo);
}

.hero.rift-drawn #heroRiftLine {
    /* expanded inline by JS */
}

.hero-coord {
    display: block;
    margin-top: 4rem;
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
    font-size: 0.75rem;
    letter-spacing: 0.22em;
    text-transform: uppercase;
    color: var(--basalt-gray);
    opacity: 0;
    animation: heroFade 1800ms var(--ease-geo) 3200ms forwards;
}

.hero-scroll-hint {
    position: absolute;
    bottom: 6vh;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 14px;
    font-family: 'Space Grotesk', sans-serif;
    font-size: 0.7rem;
    letter-spacing: 0.3em;
    text-transform: uppercase;
    color: var(--basalt-gray);
    opacity: 0;
    animation: heroFade 1800ms var(--ease-geo) 4000ms forwards;
}

.hint-line {
    width: 1px;
    height: 56px;
    background: linear-gradient(to bottom, var(--basalt-gray), transparent);
    animation: hintPulse 4s var(--ease-geo) infinite;
}

@keyframes heroFade {
    from { opacity: 0; transform: translateY(12px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes hintPulse {
    0%, 100% { opacity: 0.4; transform: scaleY(0.6); transform-origin: top; }
    50%      { opacity: 1;   transform: scaleY(1);   transform-origin: top; }
}

/* ----------------------------------------------------------
   Runic palimpsest watermark layer
   ---------------------------------------------------------- */
.rune-layer {
    position: absolute;
    top: 100vh;
    left: 0;
    right: 0;
    height: calc(100% - 100vh);
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.rune {
    position: absolute;
    width: 12vh;
    height: 20vh;
    opacity: 0.03;
    color: var(--arctic-silver);
}

.rune-1 { top: 8%;  left: 12%; transform: rotate(-3deg); }
.rune-2 { top: 22%; left: 78%; transform: rotate(4deg);  width: 14vh; height: 22vh; }
.rune-3 { top: 36%; left: 18%; transform: rotate(2deg);  }
.rune-4 { top: 48%; left: 70%; transform: rotate(-5deg); width: 16vh; height: 26vh; }
.rune-5 { top: 60%; left: 22%; transform: rotate(3deg);  }
.rune-6 { top: 72%; left: 76%; transform: rotate(-2deg); }
.rune-7 { top: 84%; left: 16%; transform: rotate(5deg);  width: 14vh; height: 22vh; }
.rune-8 { top: 92%; left: 72%; transform: rotate(-4deg); }

/* ----------------------------------------------------------
   SESSION sections — the Assembly Scroll
   ---------------------------------------------------------- */
.session {
    position: relative;
    padding: 28vh 6vw 28vh;
    z-index: 3;
    background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='240' height='276'><polygon points='120,8 232,72 232,204 120,268 8,204 8,72' fill='none' stroke='%23c9d1d9' stroke-width='0.5' stroke-opacity='0.025'/><polygon points='240,144 352,208 352,340 240,404 128,340 128,208' fill='none' stroke='%23c9d1d9' stroke-width='0.5' stroke-opacity='0.02'/><polygon points='0,144 112,208 112,340 0,404 -112,340 -112,208' fill='none' stroke='%23c9d1d9' stroke-width='0.5' stroke-opacity='0.02'/></svg>");
    background-repeat: repeat;
}

.session.coda {
    padding: 32vh 6vw 18vh;
}

.session-inner {
    max-width: var(--reading-col);
    margin: 0 auto;
    position: relative;
}

/* Timeline marker — sticky vertical year tag */
.session-marker {
    position: absolute;
    left: max(2vw, calc(50vw - var(--reading-col) / 2 - 130px));
    top: 28vh;
    height: calc(100% - 40vh);
    pointer-events: none;
}

.session-marker span {
    position: sticky;
    top: 30vh;
    display: inline-block;
    writing-mode: vertical-lr;
    transform: rotate(180deg);
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
    font-size: 0.75rem;
    letter-spacing: 0.28em;
    text-transform: uppercase;
    color: var(--basalt-gray);
    opacity: 0.4;
    transition: color 1200ms var(--ease-geo), opacity 1200ms var(--ease-geo);
}

.session.in-view .session-marker span {
    opacity: 0.85;
    color: var(--manuscript-gold);
}

/* Proclamation headings — the Logberg voice */
.proclamation {
    font-family: 'Cormorant Garamond', 'EB Garamond', Georgia, serif;
    font-weight: 600;
    font-size: clamp(2rem, 5vw, 5rem);
    line-height: 1.08;
    letter-spacing: 0.5em;
    text-transform: uppercase;
    color: var(--snow-white);
    text-align: center;
    opacity: 0;
    margin-bottom: 4rem;
    transition: opacity 1200ms var(--ease-geo),
                letter-spacing 1200ms var(--ease-geo);
    text-wrap: balance;
}

.session.in-view .proclamation {
    opacity: 1;
    letter-spacing: 0.12em;
}

.coda-mark {
    font-style: italic;
    font-weight: 500;
    font-size: clamp(1.5rem, 3.4vw, 2.6rem);
    letter-spacing: 0.06em;
    color: var(--manuscript-gold);
    text-transform: none;
}

.session.in-view .coda-mark {
    letter-spacing: 0.04em;
}

/* Tectonic divider — fracture beneath each heading */
.tectonic-divider {
    width: 100%;
    max-width: 540px;
    height: 80px;
    margin: 0 auto 3.5rem;
    opacity: 0;
    transform: scaleX(0.4);
    transform-origin: center;
    transition: opacity 1600ms var(--ease-geo) 400ms,
                transform 2400ms var(--ease-geo) 400ms;
}

.tectonic-divider svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

.session.in-view .tectonic-divider {
    opacity: 1;
    transform: scaleX(1);
}

.tectonic-divider.final {
    max-width: 220px;
    height: 40px;
}

/* Deliberation passage — narrow reading column, Lora */
.deliberation {
    font-family: 'Lora', Georgia, serif;
    font-size: 1.1rem;
    line-height: 1.95;
    color: var(--snow-white);
}

.deliberation p {
    margin-bottom: 1.6rem;
    opacity: 0;
    transform: translateY(8px);
    transition: opacity 800ms var(--ease-geo),
                transform 1200ms var(--ease-geo);
}

.session.in-view .deliberation p { opacity: 1; transform: translateY(0); }
.session.in-view .deliberation p:nth-child(1) { transition-delay: 600ms; }
.session.in-view .deliberation p:nth-child(2) { transition-delay: 800ms; }
.session.in-view .deliberation p:nth-child(3) { transition-delay: 1000ms; }
.session.in-view .deliberation p:nth-child(4) { transition-delay: 1200ms; }

.deliberation em {
    font-style: italic;
    color: var(--arctic-silver);
}

.deliberation strong {
    font-weight: 700;
    color: var(--manuscript-gold);
}

.marginalia {
    font-style: italic;
    font-weight: 700;
    color: var(--arctic-silver);
    border-left: 1px solid var(--basalt-gray);
    padding-left: 1.4rem;
    margin-top: 2.4rem !important;
    font-size: 1rem;
    opacity: 0.78;
    line-height: 1.7;
}

/* ----------------------------------------------------------
   Coda / colophon
   ---------------------------------------------------------- */
.coda .colophon {
    text-align: center;
    margin-top: 6rem;
    opacity: 0;
    transition: opacity 1600ms var(--ease-geo) 1400ms;
}

.session.in-view.coda .colophon { opacity: 1; }

.colophon p:first-child {
    font-family: 'Cormorant Garamond', serif;
    font-weight: 300;
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--snow-white);
    margin-bottom: 1.4rem;
}

.colophon .meta {
    font-family: 'Space Grotesk', sans-serif;
    font-weight: 500;
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--basalt-gray);
    line-height: 1.8;
}

/* ----------------------------------------------------------
   Section-entry aurora glow
   ---------------------------------------------------------- */
.session::before {
    content: "";
    position: absolute;
    top: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 60%;
    height: 1px;
    background: linear-gradient(90deg,
        transparent 0%,
        var(--glacier-blue) 25%,
        var(--aurora-green) 50%,
        var(--aurora-violet) 75%,
        transparent 100%);
    opacity: 0;
    transition: opacity 1500ms var(--ease-geo);
    pointer-events: none;
    filter: blur(1px);
}

.session.in-view.fresh::before {
    opacity: 0.7;
    transition: opacity 200ms ease-in;
}

/* ----------------------------------------------------------
   Responsive
   ---------------------------------------------------------- */
@media (max-width: 900px) {
    :root { --rift-x: 50vw; --reading-col: 92vw; }

    .session { padding: 18vh 5vw; }
    .session.coda { padding: 24vh 5vw 14vh; }

    .session-marker {
        position: static;
        margin: 0 auto 2rem;
        height: auto;
        text-align: center;
    }
    .session-marker span {
        position: static;
        writing-mode: horizontal-tb;
        transform: none;
    }

    .proclamation { font-size: clamp(1.6rem, 7vw, 2.6rem); margin-bottom: 2.6rem; }
    .tectonic-divider { margin-bottom: 2.4rem; }
    .deliberation { font-size: 1rem; line-height: 1.85; }

    .rune-layer { display: none; }
    .enter-link { font-size: 0.65rem; top: 18px; }
    .hero-coord { font-size: 0.65rem; margin-top: 2.5rem; }
}

@media (max-width: 520px) {
    .proclamation { font-size: 1.4rem; letter-spacing: 0.32em; }
    .session.in-view .proclamation { letter-spacing: 0.08em; }
}