/* whitepapers.xyz - Japanese research pavilion at twilight */

:root {
    --bg: #0F0F12;
    --surface: #1A1A22;
    --paper: #FFF3E0;
    --amber: #E8913A;
    --coral: #D4654A;
    --aurora-green: #78DCB4;
    --aurora-violet: #9B7ED8;
    --saffron: #C4842D;

    --ease: cubic-bezier(0.25, 0.1, 0.25, 1);

    --left-channel: 48px;
    --right-channel: 64px;
    --gutter: 24px;
}

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

html, body {
    background-color: var(--bg);
    color: var(--paper);
    font-family: "Noto Serif JP", Georgia, serif;
    font-weight: 400;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    min-height: 100vh;
    overflow-x: hidden;
    position: relative;
    background-image:
        repeating-linear-gradient(
            to right,
            transparent 0,
            transparent calc((100vw - var(--left-channel) - var(--right-channel)) / 6 - 1px),
            rgba(120, 220, 180, 0.04) calc((100vw - var(--left-channel) - var(--right-channel)) / 6 - 1px),
            rgba(120, 220, 180, 0.04) calc((100vw - var(--left-channel) - var(--right-channel)) / 6)
        ),
        radial-gradient(circle at 12% 18%, rgba(232, 145, 58, 0.025) 0px, transparent 1px),
        radial-gradient(circle at 67% 41%, rgba(155, 126, 216, 0.022) 0px, transparent 1px),
        radial-gradient(circle at 33% 76%, rgba(120, 220, 180, 0.02) 0px, transparent 1px),
        radial-gradient(circle at 88% 92%, rgba(212, 101, 74, 0.018) 0px, transparent 1px);
    background-size:
        100% 100%,
        3px 3px,
        4px 4px,
        5px 5px,
        3px 3px;
}

/* ----- Aurora border strips ----- */
.aurora-strip {
    position: fixed;
    top: 0;
    bottom: 0;
    width: 3px;
    z-index: 50;
    background: linear-gradient(
        180deg,
        var(--aurora-green) 0%,
        var(--aurora-violet) 50%,
        var(--aurora-green) 100%
    );
    background-size: 100% 200%;
    animation: aurora-cycle 20s linear infinite;
    opacity: 0.85;
    pointer-events: none;
}

.aurora-strip--left {
    left: 0;
}

.aurora-strip--right {
    right: 0;
}

@keyframes aurora-cycle {
    0% { background-position: 0% 0%; }
    100% { background-position: 0% -200%; }
}

/* ----- Top bar ----- */
.topbar {
    position: relative;
    z-index: 20;
    padding: 22px var(--right-channel) 22px var(--left-channel);
    border-bottom: 1px solid rgba(255, 243, 224, 0.08);
}

.topbar__inner {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    font-family: "Jost", "Helvetica Neue", Arial, sans-serif;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.18em;
    font-size: 0.78rem;
}

.topbar__brand {
    color: var(--paper);
}

.topbar__toggle {
    color: var(--aurora-green);
    cursor: pointer;
    transition: color 300ms var(--ease);
}

.topbar__toggle:hover {
    color: var(--amber);
}

/* ----- Hero ----- */
.hero {
    position: relative;
    height: 60vh;
    min-height: 420px;
    width: 100%;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    border-bottom: 1px solid rgba(255, 243, 224, 0.06);
}

.hero__inner {
    position: relative;
    z-index: 2;
    text-align: center;
    padding: 0 var(--right-channel) 0 var(--left-channel);
    max-width: 1200px;
    width: 100%;
}

.hero__meta {
    font-family: "IBM Plex Mono", "Courier New", monospace;
    font-size: 0.72rem;
    color: var(--saffron);
    letter-spacing: 0.3em;
    margin-bottom: 28px;
    text-transform: uppercase;
}

.hero__title {
    font-family: "Jost", "Helvetica Neue", Arial, sans-serif;
    font-weight: 700;
    font-size: clamp(2.4rem, 7vw, 5.6rem);
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--paper);
    line-height: 1;
    margin-bottom: 28px;
    text-shadow: 0 0 40px rgba(232, 145, 58, 0.08);
}

.hero__rotator {
    position: relative;
    height: 2.2em;
    margin-bottom: 36px;
}

.hero__phrase {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    font-family: "Noto Serif JP", Georgia, serif;
    font-style: italic;
    font-weight: 400;
    font-size: clamp(0.95rem, 1.2vw, 1.1rem);
    color: rgba(255, 243, 224, 0.72);
    letter-spacing: 0.04em;
    opacity: 0;
    transition: opacity 1200ms var(--ease);
}

.hero__phrase.is-active {
    opacity: 1;
}

.hero__footnote {
    display: inline-flex;
    align-items: center;
    gap: 12px;
    font-family: "IBM Plex Mono", "Courier New", monospace;
    font-size: 0.7rem;
    letter-spacing: 0.3em;
    color: var(--aurora-green);
    text-transform: uppercase;
}

.hero__pulse {
    width: 6px;
    height: 6px;
    background: var(--aurora-green);
    display: inline-block;
    box-shadow: 0 0 8px var(--aurora-green);
    animation: pulse 2.4s var(--ease) infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.25; }
}

/* ----- Leaf-fall particles ----- */
.leaffall {
    position: absolute;
    inset: 0;
    pointer-events: none;
    z-index: 1;
}

.leaf {
    position: absolute;
    top: -20px;
    width: 8px;
    height: 8px;
    background: var(--amber);
    opacity: 0.2;
    transform: rotate(45deg);
    animation: leaf-fall 14s linear infinite;
}

.leaf--1 { left: 8%;  animation-delay: 0s;    animation-duration: 14s; width: 6px; height: 6px; }
.leaf--2 { left: 20%; animation-delay: 2.5s;  animation-duration: 16s; width: 8px; height: 8px; }
.leaf--3 { left: 35%; animation-delay: 5s;    animation-duration: 13s; width: 7px; height: 7px; }
.leaf--4 { left: 48%; animation-delay: 1.2s;  animation-duration: 18s; width: 9px; height: 9px; }
.leaf--5 { left: 64%; animation-delay: 3.8s;  animation-duration: 15s; width: 6px; height: 6px; }
.leaf--6 { left: 78%; animation-delay: 6.5s;  animation-duration: 17s; width: 10px; height: 10px; }
.leaf--7 { left: 90%; animation-delay: 4.2s;  animation-duration: 14s; width: 7px; height: 7px; }

@keyframes leaf-fall {
    0% {
        transform: translateY(0) translateX(0) rotate(45deg);
        opacity: 0;
    }
    8% { opacity: 0.22; }
    50% {
        transform: translateY(50vh) translateX(20px) rotate(135deg);
        opacity: 0.18;
    }
    92% { opacity: 0.18; }
    100% {
        transform: translateY(80vh) translateX(-12px) rotate(225deg);
        opacity: 0;
    }
}

/* ----- Pavilion / sections ----- */
.pavilion {
    position: relative;
}

.stack {
    position: relative;
    padding: 96px var(--right-channel) 96px calc(var(--left-channel) + 56px);
}

.waypoint {
    position: absolute;
    left: 0;
    top: 96px;
    width: var(--left-channel);
    transform-origin: left top;
    transform: rotate(-90deg) translateX(-100%);
    font-family: "Jost", "Helvetica Neue", Arial, sans-serif;
    font-weight: 500;
    font-size: 0.72rem;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--saffron);
    white-space: nowrap;
    opacity: 0;
    transition: opacity 600ms var(--ease) 300ms, transform 600ms var(--ease) 300ms;
}

.stack.is-visible .waypoint {
    opacity: 1;
    transform: rotate(-90deg) translateX(-100%);
}

/* ----- Masonry ----- */
.masonry {
    column-count: 3;
    column-gap: var(--gutter);
}

@media (max-width: 960px) {
    .masonry { column-count: 2; }
}

@media (max-width: 600px) {
    .masonry { column-count: 1; }
    .stack {
        padding-left: calc(var(--left-channel) + 16px);
        padding-right: 28px;
    }
}

/* ----- Card ----- */
.card {
    break-inside: avoid;
    margin-bottom: var(--gutter);
    background: rgba(255, 243, 224, 0.06);
    border: 1px solid rgba(120, 220, 180, 0.15);
    padding: 0;
    position: relative;
    perspective: 1000px;
    transform-style: preserve-3d;
    opacity: 0;
    transform: translateY(30px);
    transition:
        opacity 500ms var(--ease),
        transform 500ms var(--ease),
        border-color 600ms var(--ease);
    will-change: transform;
}

.card.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.card.is-pulsing {
    border-color: rgba(120, 220, 180, 0.4);
}

.card--tall .card__inner {
    min-height: 360px;
}

.card--wide .card__inner {
    min-height: 200px;
}

.card__inner {
    position: relative;
    padding: 28px 26px 24px;
    transform-style: preserve-3d;
    transition: transform 200ms var(--ease);
    background: linear-gradient(
        180deg,
        rgba(232, 145, 58, 0.04) 0%,
        rgba(255, 243, 224, 0.0) 100%
    );
}

.card__meta {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    font-family: "IBM Plex Mono", "Courier New", monospace;
    font-size: 0.72rem;
    letter-spacing: 0.18em;
    color: var(--aurora-green);
    text-transform: uppercase;
    padding-bottom: 14px;
    margin-bottom: 18px;
    border-bottom: 1px solid rgba(255, 243, 224, 0.07);
    transform: translateZ(0);
}

.card__cls {
    color: var(--amber);
}

.card__date {
    color: rgba(255, 243, 224, 0.55);
}

.card__title {
    font-family: "Jost", "Helvetica Neue", Arial, sans-serif;
    font-weight: 500;
    font-size: clamp(1.05rem, 1.4vw, 1.32rem);
    letter-spacing: 0.06em;
    text-transform: uppercase;
    line-height: 1.25;
    color: var(--paper);
    margin-bottom: 16px;
    transition: color 300ms var(--ease);
    transform: translateZ(20px);
}

.card:hover .card__title {
    color: var(--amber);
}

.card__body {
    font-family: "Noto Serif JP", Georgia, serif;
    font-size: clamp(0.92rem, 1vw, 1rem);
    line-height: 1.85;
    letter-spacing: 0.01em;
    color: rgba(255, 243, 224, 0.78);
    margin-bottom: 22px;
    transform: translateZ(10px);
}

.card__tags {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 8px 10px;
    margin-bottom: 22px;
    transform: translateZ(14px);
}

.card__tags li {
    font-family: "IBM Plex Mono", "Courier New", monospace;
    font-size: 0.66rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    color: var(--aurora-violet);
    border: 1px solid rgba(155, 126, 216, 0.28);
    padding: 4px 9px;
}

.card__footer {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    padding-top: 16px;
    border-top: 1px solid rgba(255, 243, 224, 0.07);
    font-family: "IBM Plex Mono", "Courier New", monospace;
    font-size: 0.7rem;
    letter-spacing: 0.14em;
    color: var(--saffron);
    text-transform: uppercase;
}

.card__author {
    color: rgba(255, 243, 224, 0.6);
}

.card__pages {
    color: var(--coral);
}

/* ----- Footer ----- */
.footer {
    padding: 48px var(--right-channel) 56px var(--left-channel);
    margin-top: 32px;
}

.footer__rule {
    height: 1px;
    background: rgba(255, 243, 224, 0.08);
    margin-bottom: 28px;
}

.footer__mark {
    display: block;
    text-align: center;
    font-family: "Jost", "Helvetica Neue", Arial, sans-serif;
    font-weight: 500;
    font-size: 0.78rem;
    letter-spacing: 0.32em;
    text-transform: uppercase;
    color: var(--saffron);
}

/* ----- Responsive: rotate waypoint inline on small screens ----- */
@media (max-width: 600px) {
    .waypoint {
        position: relative;
        transform: none;
        display: block;
        margin-bottom: 18px;
        margin-left: -28px;
    }
    .stack.is-visible .waypoint { transform: none; }
    .topbar {
        padding-left: 28px;
        padding-right: 28px;
    }
    .footer {
        padding-left: 28px;
        padding-right: 28px;
    }
    .hero__inner {
        padding-left: 28px;
        padding-right: 28px;
    }
}

/* ----- Reduced motion ----- */
@media (prefers-reduced-motion: reduce) {
    .aurora-strip { animation: none; }
    .leaf { animation: none; opacity: 0; }
    .hero__pulse { animation: none; }
    .card,
    .card.is-visible,
    .waypoint {
        opacity: 1;
        transform: none;
        transition: none;
    }
}