/* ==========================================================================
   site.css — shared design system
   Víctor Busqué · Living Engineering Notes
   Landing page specifics live inline in index.html; figure specifics live
   inline in each blog post. This file is the shared skeleton.
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=DM+Mono:wght@300;400;500&family=Instrument+Serif:ital@0;1&family=Newsreader:ital,opsz,wght@0,6..72,400;0,6..72,500;0,6..72,600;1,6..72,400&family=Unbounded:wght@400;500;600;700&display=swap');

/* ── Tokens ─────────────────────────────────────────────── */
:root {
    --ink: #101010;
    --paper: #f2f0e9;
    --paper-2: #ece9de;
    --acid: #c7ff3d;
    --blue: #546cff;
    --orange: #ff6b2c;
    --muted: #716f68;
    --line: #111111;

    /* stages (dark diagram canvases) */
    --stage: #121212;
    --stage-2: #1a1a1a;
    --grid: #ffffff0d;

    /* motion system — premium editorial */
    --ease-out: cubic-bezier(.16, 1, .3, 1);       /* entrances: decelerate */
    --ease-in: cubic-bezier(.55, 0, .85, .36);     /* exits: accelerate */
    --ease-snap: cubic-bezier(.2, 0, 0, 1);        /* micro-interactions */
    --ease-swift: cubic-bezier(.4, 0, .2, 1);      /* on-screen state */
    --t-fast: 180ms;
    --t-med: 400ms;
    --t-slow: 800ms;
    --t-dramatic: 1100ms;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 84px;
}

body {
    background: var(--paper);
    color: var(--ink);
    font-family: "Newsreader", Georgia, serif;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

::selection {
    background: var(--acid);
    color: var(--ink);
}

a {
    color: inherit;
    text-decoration: none;
}

:focus-visible {
    outline: 2px solid var(--blue);
    outline-offset: 3px;
}

.mono { font-family: "DM Mono", monospace; }
.serif { font-family: "Instrument Serif", serif; }

/* ── Scroll progress ────────────────────────────────────── */
.progress {
    position: fixed;
    top: 0;
    left: 0;
    height: 3px;
    width: 100%;
    background: var(--acid);
    transform-origin: 0 50%;
    transform: scaleX(0);
    z-index: 60;
    pointer-events: none;
}

/* ── Cursor ─────────────────────────────────────────────── */
.cursor-dot,
.cursor-ring {
    position: fixed;
    top: 0;
    left: 0;
    border-radius: 50%;
    pointer-events: none;
    z-index: 70;
    transform: translate(-50%, -50%);
}
.cursor-dot {
    width: 6px;
    height: 6px;
    background: var(--acid);
}
.cursor-ring {
    width: 30px;
    height: 30px;
    border: 1px solid #10101055;
    transition: width var(--t-fast) var(--ease-snap), height var(--t-fast) var(--ease-snap),
        border-color var(--t-fast) var(--ease-snap), opacity var(--t-fast) var(--ease-snap);
}
.cursor-ring.is-hot {
    width: 46px;
    height: 46px;
    border-color: var(--orange);
}
@media (hover: none), (pointer: coarse) {
    .cursor-dot, .cursor-ring { display: none; }
}

/* ── Nav ────────────────────────────────────────────────── */
nav {
    height: 70px;
    border-bottom: 1px solid var(--line);
    display: flex;
    align-items: center;
    padding: 0 4vw;
    position: sticky;
    top: 0;
    background: #f2f0e9e8;
    backdrop-filter: blur(16px);
    z-index: 50;
}

.logo {
    font-family: "Unbounded", sans-serif;
    font-size: 18px;
    font-weight: 600;
    letter-spacing: -.06em;
    display: inline-flex;
    align-items: center;
}
.logo i {
    display: inline-block;
    width: 8px;
    height: 8px;
    background: var(--acid);
    border-radius: 50%;
    margin-left: 6px;
    animation: blink 1.8s var(--ease-snap) infinite, ping 2.4s var(--ease-out) infinite;
}

nav .links {
    margin-left: auto;
    display: flex;
    gap: 30px;
    font-size: 13px;
}
nav .links a {
    position: relative;
    padding: 6px 0;
    transition: color var(--t-fast) var(--ease-snap);
}
nav .links a::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 1px;
    background: var(--ink);
    transform: scaleX(0);
    transform-origin: 100% 50%;
    transition: transform var(--t-med) var(--ease-out);
}
nav .links a:hover::after {
    transform: scaleX(1);
    transform-origin: 0 50%;
}

.status {
    margin-left: 30px;
    padding-left: 30px;
    border-left: 1px solid #11111133;
    font: 10px "DM Mono";
    color: #777;
}
.status b {
    color: var(--ink);
    font-weight: 500;
}

/* Nav toggle — injected by site.js, only visible on small screens.
   The burger morphs into an X; the menu drops from the nav. */
.nav-toggle {
    display: none;
    margin-left: auto;
    width: 42px;
    height: 42px;
    place-items: center;
    border: 1px solid var(--line);
    background: transparent;
    cursor: pointer;
    transition: background var(--t-fast) var(--ease-snap),
        transform var(--t-fast) var(--ease-snap);
}
.nav-toggle:hover { background: var(--ink); }
.nav-toggle:active { transform: scale(.92); }
.nav-toggle-icon {
    position: relative;
    display: block;
    width: 16px;
    height: 10px;
}
.nav-toggle-icon i {
    position: absolute;
    left: 0;
    width: 100%;
    height: 1.6px;
    background: var(--ink);
    transition: transform var(--t-med) var(--ease-out),
        opacity var(--t-fast) var(--ease-snap),
        background var(--t-fast) var(--ease-snap);
}
.nav-toggle-icon i:nth-child(1) { top: 0; }
.nav-toggle-icon i:nth-child(2) { top: 4px; }
.nav-toggle-icon i:nth-child(3) { top: 8px; }
.nav-toggle:hover .nav-toggle-icon i { background: var(--acid); }
.nav-toggle.is-open .nav-toggle-icon i:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.nav-toggle.is-open .nav-toggle-icon i:nth-child(2) { opacity: 0; }
.nav-toggle.is-open .nav-toggle-icon i:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }

/* ── Marquee strip ──────────────────────────────────────── */
.marquee {
    border-bottom: 1px solid var(--line);
    overflow: hidden;
    background: var(--ink);
    color: var(--paper);
    padding: 14px 0;
}
.marquee-track {
    display: flex;
    width: max-content;
    animation: marquee 30s linear infinite;
    will-change: transform;
}
.marquee span {
    font: 11px "DM Mono";
    letter-spacing: .2em;
    text-transform: uppercase;
    white-space: nowrap;
    padding: 0 22px;
}
.marquee span i {
    font-style: normal;
    color: var(--acid);
}

/* ── Masked line reveals (scroll-triggered) ─────────────── */
.mask .row {
    display: block;
    overflow: hidden;
    padding-bottom: .06em;
    margin-bottom: -.06em;
}
.mask .row > span {
    display: block;
    transform: translateY(112%);
    transition: transform 1s var(--ease-out);
    transition-delay: calc(var(--i, 0) * .12s);
}
.mask.seen .row > span {
    transform: translateY(0);
}

/* ── Load-time line reveals (heroes) ────────────────────── */
.h-line {
    display: block;
    overflow: hidden;
    padding-bottom: .08em;
    margin-bottom: -.08em;
}
.h-line > span {
    display: block;
    transform: translateY(112%);
    animation: rise var(--t-dramatic) var(--ease-out) both;
}
.h-line:nth-child(1) > span { animation-delay: .1s; }
.h-line:nth-child(2) > span { animation-delay: .22s; }
.h-line:nth-child(3) > span { animation-delay: .34s; }

/* ── Scroll reveals ─────────────────────────────────────── */
.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity var(--t-slow) var(--ease-out), transform var(--t-slow) var(--ease-out);
    transition-delay: var(--d, 0s);
}
.reveal.seen {
    opacity: 1;
    transform: none;
}
.stagger > * {
    opacity: 0;
    transform: translateY(24px);
    transition: opacity var(--t-slow) var(--ease-out), transform var(--t-slow) var(--ease-out);
}
.stagger.seen > * {
    opacity: 1;
    transform: none;
}
.stagger > *:nth-child(1) { transition-delay: .05s; }
.stagger > *:nth-child(2) { transition-delay: .15s; }
.stagger > *:nth-child(3) { transition-delay: .25s; }
.stagger > *:nth-child(4) { transition-delay: .35s; }
.stagger > *:nth-child(5) { transition-delay: .45s; }

/* ── Buttons / tags ─────────────────────────────────────── */
.btn {
    display: inline-block;
    font: 10px "DM Mono";
    letter-spacing: .16em;
    text-transform: uppercase;
    border: 1px solid var(--line);
    padding: 12px 18px;
    background: transparent;
    cursor: pointer;
    transition: background var(--t-fast) var(--ease-snap), color var(--t-fast) var(--ease-snap);
}
.btn:hover {
    background: var(--ink);
    color: var(--paper);
}

.tag {
    border: 1px solid #aaa;
    padding: 6px 9px;
    font: 10px "DM Mono";
    background: var(--paper);
    transition: border-color var(--t-fast) var(--ease-snap), transform var(--t-fast) var(--ease-snap);
    cursor: default;
}

/* ── Figure system ──────────────────────────────────────── */
/*
   Every figure is a dark animated canvas with a head bar and a caption.
   Two kinds:
     · looping figures — pure CSS choreography, get PAUSE / REPLAY controls
     · scripted figures — driven by a draw(i) function registered in
       window.__figScripts, get PREV / PLAY / NEXT / RESET controls.
   See blog/template.html for the recipe.
*/
.fig {
    margin: 11vh auto;
    width: 100%;
}
.fig-head {
    display: flex;
    align-items: center;
    gap: 16px;
    border: 1px solid var(--line);
    border-bottom: 0;
    background: var(--paper-2);
    padding: 12px 16px;
}
.fig-no {
    font: 10px "DM Mono";
    letter-spacing: .14em;
    color: var(--orange);
}
.fig-name {
    font: 10px "DM Mono";
    letter-spacing: .18em;
}
.fig-readout {
    font: 10px "DM Mono";
    color: #666;
    margin-left: auto;
    text-align: right;
    max-width: 46%;
    line-height: 1.5;
}
.fig-controls {
    display: flex;
    gap: 6px;
    flex-shrink: 0;
}
.fig-btn {
    font: 9px "DM Mono";
    letter-spacing: .12em;
    border: 1px solid var(--line);
    background: var(--paper);
    padding: 8px 10px;
    cursor: pointer;
    transition: background var(--t-fast) var(--ease-snap), color var(--t-fast) var(--ease-snap),
        transform var(--t-fast) var(--ease-snap);
}
.fig-btn:hover {
    background: var(--ink);
    color: var(--paper);
}
.fig-btn:active {
    transform: scale(.94);
}
.fig-btn.is-active {
    background: var(--ink);
    color: var(--acid);
}
.fig-btn:disabled {
    opacity: .3;
    cursor: default;
    transform: none;
}

.fig-body {
    border: 1px solid var(--line);
    background-color: var(--stage);
    background-image: linear-gradient(var(--grid) 1px, transparent 1px),
        linear-gradient(90deg, var(--grid) 1px, transparent 1px);
    background-size: 32px 32px;
    position: relative;
    overflow: hidden;
    min-height: 380px;
    color: #fff;
}
.fig-body::after {
    content: "";
    position: absolute;
    width: 200px;
    height: 200px;
    border: 1px solid #ffffff12;
    border-radius: 50%;
    right: -100px;
    bottom: -100px;
    pointer-events: none;
}

/* pause / restart mechanics */
.fig.is-paused .fig-body *,
.fig.is-paused .fig-body *::before,
.fig.is-paused .fig-body *::after {
    animation-play-state: paused !important;
}
.fig.is-restarting .fig-body *,
.fig.is-restarting .fig-body *::before,
.fig.is-restarting .fig-body *::after {
    animation: none !important;
    transition: none !important;
}

.fig-caption {
    margin-top: 16px;
    font-size: 13.5px;
    line-height: 1.65;
    color: var(--muted);
    max-width: 760px;
}
.fig-caption b {
    font-family: "DM Mono";
    font-size: 9.5px;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: var(--orange);
    font-weight: 500;
    margin-right: 8px;
}

/* ── Blog post layout ───────────────────────────────────── */
.post-hero {
    border-bottom: 1px solid var(--line);
    padding: 9vh 4vw 7vh;
    position: relative;
    overflow: hidden;
}
.post-hero .ghost {
    position: absolute;
    right: -1vw;
    top: 2vh;
    font: italic 160px/1 "Instrument Serif";
    color: #1111110d;
    pointer-events: none;
    animation: floaty 9s var(--ease-swift) infinite;
}
.crumb {
    font: 10px "DM Mono";
    letter-spacing: .18em;
    text-transform: uppercase;
    color: #777;
    margin-bottom: 34px;
}
.crumb a {
    border-bottom: 1px solid #777;
    padding-bottom: 2px;
    transition: color var(--t-fast) var(--ease-snap), border-color var(--t-fast) var(--ease-snap);
}
.crumb a:hover {
    color: var(--ink);
    border-color: var(--ink);
}
.post-hero h1 {
    font-family: "Unbounded", sans-serif;
    font-weight: 500;
    font-size: clamp(46px, 7.5vw, 116px);
    letter-spacing: -.07em;
    line-height: .86;
    margin: 0 0 34px;
}
.post-hero h1 em {
    font-family: "Instrument Serif";
    font-style: italic;
    font-weight: 400;
    letter-spacing: -.04em;
}
.post-hero .dek {
    font-size: 18px;
    line-height: 1.6;
    max-width: 620px;
    color: #45433f;
    opacity: 0;
    transform: translateY(20px);
    animation: fade-rise var(--t-slow) var(--ease-out) .55s both;
}
.post-meta {
    margin-top: 40px;
    display: flex;
    gap: 26px;
    flex-wrap: wrap;
    font: 10px "DM Mono";
    letter-spacing: .14em;
    text-transform: uppercase;
    color: #777;
}
.post-meta b {
    color: var(--ink);
    font-weight: 500;
}

.post-prose {
    max-width: 700px;
    margin: 0 auto;
    padding: 5vh 4vw 0;
}
.post-prose > p {
    font-size: 18px;
    line-height: 1.74;
    color: #33322e;
    margin-bottom: 1.5em;
}
.post-prose > p strong {
    font-weight: 600;
}
.post-prose h2 {
    font-family: "Unbounded", sans-serif;
    font-weight: 500;
    font-size: clamp(25px, 3.4vw, 38px);
    letter-spacing: -.045em;
    line-height: 1.05;
    margin: 11vh 0 20px;
    display: flex;
    align-items: baseline;
    gap: 18px;
}
.post-prose h2 .sec-no {
    font: 10px "DM Mono";
    letter-spacing: .14em;
    color: var(--orange);
    align-self: center;
}
.post-prose .callout {
    border-left: 4px solid var(--acid);
    background: var(--paper-2);
    padding: 22px 26px;
    margin: 5vh 0;
    font: italic 23px/1.45 "Instrument Serif";
}
.post-prose .callout em {
    font-style: normal;
}
.post-prose .aside {
    font: 11px/1.7 "DM Mono";
    color: #777;
    border-top: 1px solid #d8d4c6;
    padding-top: 12px;
    margin: 6vh 0;
}

/* ── Post navigation ────────────────────────────────────── */
.post-nav {
    display: grid;
    grid-template-columns: 1fr 1fr;
    border-top: 1px solid var(--line);
    margin-top: 12vh;
}
.post-nav a {
    padding: 44px 4vw;
    position: relative;
}
.post-nav a + a {
    border-left: 1px solid var(--line);
    text-align: right;
}
.post-nav .dir {
    font: 10px "DM Mono";
    letter-spacing: .18em;
    text-transform: uppercase;
    color: #777;
}
.post-nav .t {
    font-family: "Unbounded", sans-serif;
    font-weight: 500;
    font-size: clamp(18px, 2.4vw, 26px);
    letter-spacing: -.03em;
    margin-top: 12px;
    display: block;
    transition: color var(--t-fast) var(--ease-snap);
}
.post-nav a:hover .t {
    color: var(--blue);
}

/* ── Footer ─────────────────────────────────────────────── */
footer {
    padding: 6vw 4vw 3vw;
    background: var(--ink);
    color: white;
    position: relative;
    overflow: hidden;
}
footer::after {
    content: "VB";
    position: absolute;
    right: -2vw;
    bottom: -8vw;
    font: 500 30vw/1 "Unbounded";
    letter-spacing: -.12em;
    color: #ffffff05;
    pointer-events: none;
    animation: floaty 10s var(--ease-swift) infinite;
}
.footer-big {
    font-family: "Unbounded", sans-serif;
    font-weight: 600;
    font-size: clamp(65px, 10vw, 170px);
    line-height: .78;
    letter-spacing: -.07em;
}
.footer-big em {
    font-family: "Instrument Serif";
    font-weight: 400;
    color: var(--acid);
}
.foot {
    margin-top: 80px;
    padding-top: 18px;
    border-top: 1px solid #555;
    display: flex;
    justify-content: space-between;
    gap: 20px;
    flex-wrap: wrap;
    font: 10px "DM Mono";
    color: #999;
}

/* ── Keyframes ──────────────────────────────────────────── */
@keyframes rise { to { transform: translateY(0); } }
@keyframes fade-rise { to { opacity: 1; transform: none; } }
@keyframes blink { 50% { opacity: .2; } }
@keyframes ping {
    0% { box-shadow: 0 0 0 0 #c7ff3d55; }
    70% { box-shadow: 0 0 0 9px #c7ff3d00; }
    100% { box-shadow: 0 0 0 0 #c7ff3d00; }
}
@keyframes marquee { to { transform: translateX(-50%); } }
@keyframes floaty {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-14px); }
}
@keyframes pop {
    0%, 12% { transform: scale(1); }
    30% { transform: scale(1.18); }
    40%, 100% { transform: scale(1); }
}

/* ── Responsive ─────────────────────────────────────────── */
@media (max-width: 850px) {
    .nav-toggle { display: grid; }
    .status { display: none; }

    /* dropdown panel — closes fast (accelerate), opens staggered (decelerate) */
    nav .links {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        margin: 0;
        padding: 8px 4vw 16px;
        flex-direction: column;
        gap: 0;
        background: var(--paper);
        border-bottom: 1px solid var(--line);
        box-shadow: 0 30px 46px -34px #11111180;
        transform-origin: 50% 0;
        transform: scaleY(0);
        visibility: hidden;
        transition: transform var(--t-med) var(--ease-in),
            visibility 0s linear var(--t-med);
    }
    nav.is-open .links {
        transform: scaleY(1);
        visibility: visible;
        transition: transform var(--t-med) var(--ease-out),
            visibility 0s;
    }
    nav .links a {
        padding: 13px 2px;
        font-size: 15px;
        border-bottom: 1px solid #11111114;
        opacity: 0;
        transform: translateY(10px);
        transition: opacity var(--t-fast) var(--ease-out),
            transform var(--t-fast) var(--ease-out);
    }
    nav .links a:last-child { border-bottom: 0; }
    nav .links a::after { bottom: 6px; }
    nav.is-open .links a {
        opacity: 1;
        transform: none;
        transition: opacity var(--t-med) var(--ease-out),
            transform var(--t-med) var(--ease-out);
        transition-delay: calc(60ms + var(--i, 0) * 60ms);
    }
    .fig-body { min-height: 300px; }
    .fig-head { flex-wrap: wrap; gap: 10px; }
    .fig-readout { max-width: 100%; margin-left: 0; }
    .post-nav { grid-template-columns: 1fr; }
    .post-nav a + a { border-left: 0; border-top: 1px solid var(--line); text-align: left; }
    .post-hero .ghost { font-size: 100px; }
}

/* ── Reduced motion ─────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: .01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: .01ms !important;
        scroll-behavior: auto !important;
    }
    nav .links { transition-delay: 0s; }
    .reveal, .stagger > *, .h-line > span, .post-hero .dek {
        opacity: 1 !important;
        transform: none !important;
    }
    .fig.is-paused .fig-body *,
    .fig.is-paused .fig-body *::before,
    .fig.is-paused .fig-body *::after {
        animation-play-state: initial !important;
    }
}