/* hpekkan.com. The hero is always dark (a camera feed); the rest follows the visitor's theme. */
:root {
  --bg: #f6f5f1; --panel: #ffffff; --ink: #15171a; --ink2: #4d535b; --ink3: #767c84;
  --rule: #e2e0d8; --accent: #11784a; --accent-ink: #ffffff; --chip: #eef3ee;
  --feed: #07090c; --box: #b6ff3b; --you: #3be3ff; --out: #ff5c8a;
  --display: "Space Grotesk", "Inter", system-ui, sans-serif;
  --body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, monospace;
  --wrap: 1120px;
  color-scheme: light dark;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0c0e11; --panel: #13161a; --ink: #eceae4; --ink2: #b3b8be; --ink3: #8a9097;
    --rule: #252a30; --accent: #b6ff3b; --accent-ink: #0b0d10; --chip: #1a1f24;
  }
}
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 72px; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 17px/1.65 var(--body); -webkit-font-smoothing: antialiased; }
img { max-width: 100%; height: auto; }
a { color: var(--accent); text-underline-offset: 3px; }
h1, h2, h3 { font-family: var(--display); line-height: 1.1; letter-spacing: -.02em; margin: 0; }
h2 { font-size: clamp(30px, 4.2vw, 46px); margin-bottom: 28px; max-width: 20ch; }
h3 { font-size: 21px; }
p { margin: 0 0 16px; }
:focus-visible { outline: 2px solid var(--you); outline-offset: 3px; }
.sr-only, .hp { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.skip { position: absolute; left: 12px; top: -60px; z-index: 50; padding: 10px 14px; background: var(--box); color: #000; border-radius: 8px; }
.skip:focus { top: 12px; }

/* Top bar: dark glass, readable over the hero and the page. */
.bar {
  position: fixed; inset: 0 0 auto; z-index: 20; display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: calc(10px + env(safe-area-inset-top, 0px)) max(20px, env(safe-area-inset-right, 0px)) 10px max(20px, env(safe-area-inset-left, 0px));
  background: rgba(7, 9, 12, .72); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, .06); color: #eceae4;
}
.brand { display: flex; align-items: center; gap: 10px; color: inherit; text-decoration: none; font: 600 15px/1 var(--display); letter-spacing: -.01em; }
.bar nav { display: flex; align-items: center; gap: 22px; font: 500 13px/1 var(--mono); }
.bar nav a { color: #c9ccd0; text-decoration: none; }
.bar nav a:hover { color: #fff; }
.bar .bar-cta { color: #07090c; background: var(--box); padding: 9px 14px; border-radius: 999px; }
.bar .bar-cta:hover { color: #07090c; background: #ceff7a; }
@media (max-width: 720px) { .bar nav a:not(.bar-cta) { display: none; } }

/* Hero */
.hero { position: relative; min-height: max(600px, min(100svh, 860px)); background: var(--feed); color: #f2f1ec; overflow: hidden; display: flex; align-items: flex-end; }
.hero canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; cursor: crosshair; touch-action: pan-y; }
.hero::after { /* keeps the copy readable over the moving feed */
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background: radial-gradient(120% 90% at 0% 100%, rgba(7, 9, 12, .92) 0%, rgba(7, 9, 12, .55) 45%, rgba(7, 9, 12, 0) 75%);
}
.hero-copy { position: relative; z-index: 2; width: 100%; max-width: var(--wrap); margin: 0 auto; padding: 120px 24px clamp(56px, 9vh, 96px); pointer-events: none; }
.hero-copy a { pointer-events: auto; }
.eyebrow, .kicker { font: 500 12.5px/1 var(--mono); letter-spacing: .14em; text-transform: uppercase; margin-bottom: 18px; }
.eyebrow { color: var(--box); }
.kicker { color: var(--accent); }
.hero h1 { font-size: clamp(46px, 9.5vw, 112px); font-weight: 700; letter-spacing: -.035em; margin-bottom: 16px; }
.role { font: 500 clamp(17px, 2.2vw, 21px)/1.4 var(--display); margin-bottom: 14px; }
.role .tag { display: block; margin-top: 4px; font: 400 14px/1.5 var(--mono); color: #aeb3b8; }
.intro { font-size: clamp(17px, 2vw, 20px); color: #d9d8d2; max-width: 36ch; }
.actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 28px 0 0; }
.btn { display: inline-flex; align-items: center; justify-content: center; min-height: 46px; padding: 0 20px; border-radius: 999px; border: 1px solid currentColor;
  font: 600 15px/1 var(--body); text-decoration: none; color: inherit; background: transparent; cursor: pointer; }
.btn.primary { background: var(--box); border-color: var(--box); color: #07090c; }
.btn.primary:hover { background: #ceff7a; }
.hero .btn:not(.primary):hover { background: rgba(255, 255, 255, .08); }
.hud { position: absolute; z-index: 2; pointer-events: none; margin: 0; font: 500 12px/1 var(--mono); letter-spacing: .06em; color: #cfd3d6;
  padding: 9px 12px; border: 1px solid rgba(182, 255, 59, .28); border-radius: 8px; background: rgba(7, 9, 12, .6); }
.hero .hud { top: calc(76px + env(safe-area-inset-top, 0px)); left: 24px; }
.hud b { color: var(--box); font-weight: 500; }
.hud .rec { color: var(--out); animation: blink 1.6s steps(2, start) infinite; }
.hud .dot { color: var(--box); }
.hud .sep { color: #5d646b; }
@keyframes blink { to { visibility: hidden; } }
.hint { position: absolute; z-index: 2; pointer-events: none; right: 24px; bottom: 22px; margin: 0; font: 400 12px/1.4 var(--mono); color: #8d949a; max-width: 30ch; text-align: right; }
.hint-touch { display: none; }
@media (hover: none) { .hint-pointer { display: none; } .hint-touch { display: inline; } }
@media (max-width: 640px) { .hint { display: none; } .hero .hud { left: 20px; } .hero-copy { padding-inline: 20px; } }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } .hud .rec { animation: none; } .hint { display: none; } }

/* Sections */
.section { max-width: var(--wrap); margin: 0 auto; padding: clamp(72px, 11vw, 128px) 24px 0; }
@media (max-width: 640px) { .section { padding-inline: 20px; } }
.about { display: grid; grid-template-columns: minmax(0, 340px) minmax(0, 1fr); gap: clamp(32px, 6vw, 80px); align-items: start; }
.about p { color: var(--ink2); max-width: 62ch; }
@media (max-width: 800px) { .about { grid-template-columns: 1fr; } .portrait { max-width: 300px; } }
.portrait { position: relative; margin: 0; padding: 14px; }
.portrait img { display: block; width: 100%; aspect-ratio: 1; object-fit: cover; border-radius: 16px; }
.portrait::before { /* detection-box corners around the photo */
  content: ""; position: absolute; inset: 0; pointer-events: none;
  --c: var(--accent); --l: 26px; --t: 3px;
  background:
    linear-gradient(var(--c) 0 0) top left / var(--l) var(--t) no-repeat, linear-gradient(var(--c) 0 0) top left / var(--t) var(--l) no-repeat,
    linear-gradient(var(--c) 0 0) top right / var(--l) var(--t) no-repeat, linear-gradient(var(--c) 0 0) top right / var(--t) var(--l) no-repeat,
    linear-gradient(var(--c) 0 0) bottom left / var(--l) var(--t) no-repeat, linear-gradient(var(--c) 0 0) bottom left / var(--t) var(--l) no-repeat,
    linear-gradient(var(--c) 0 0) bottom right / var(--l) var(--t) no-repeat, linear-gradient(var(--c) 0 0) bottom right / var(--t) var(--l) no-repeat;
}
.portrait figcaption { position: absolute; left: 14px; top: -12px; padding: 5px 8px; border-radius: 4px; background: var(--accent); color: var(--accent-ink); font: 500 12px/1 var(--mono); }
.chips li { padding: 7px 12px; border-radius: 999px; background: var(--chip); color: var(--ink); font-size: 14px; line-height: 1.3; }

.cards { display: grid; gap: 18px; }
.built { grid-template-columns: minmax(0, 1fr); }
@media (min-width: 800px) { /* two cards side by side; the one with a demo spans the row, demo on the right */
  .built { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .built .has-visual { grid-column: 1 / -1; display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 380px); grid-template-rows: auto auto 1fr; column-gap: 40px; }
  .built .has-visual .chips { align-self: start; }
  .built .has-visual .demo { grid-column: 2; grid-row: 1 / 4; margin-top: 0; }
}
.card { background: var(--panel); border: 1px solid var(--rule); border-radius: 18px; padding: 26px; position: relative; transition: transform .2s ease, border-color .2s ease; }
.card:hover { transform: translateY(-3px); border-color: var(--accent); }
@media (prefers-reduced-motion: reduce) { .card, .card:hover { transition: none; transform: none; } }
.card h3 { margin-bottom: 14px; }
.chips { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: 7px; }
.chips li { font-size: 13px; }
.card p { color: var(--ink2); }
.card .chips { margin-top: 16px; }
.lede { color: var(--ink2); max-width: 62ch; font-size: 18px; }
.lede + .chips { margin-top: 20px; }

/* Simulated feeds: always dark like the hero, with real buttons in a bar below the canvas. */
.feed { margin-top: 32px; border-radius: 18px; overflow: hidden; background: var(--feed); color: #c9ccd0; border: 1px solid rgba(255, 255, 255, .06); }
.screen { position: relative; aspect-ratio: 2 / 1;
  background: linear-gradient(rgba(255, 255, 255, .045) 1px, transparent 1px) 0 0 / 48px 48px, linear-gradient(90deg, rgba(255, 255, 255, .045) 1px, transparent 1px) 0 0 / 48px 48px, var(--feed); }
@media (max-width: 640px) { .screen { aspect-ratio: 4 / 3; } .screen.tall { aspect-ratio: 3 / 4; } }
.screen canvas { position: absolute; inset: 0; width: 100%; height: 100%; display: block; cursor: crosshair; touch-action: pan-y; }
.screen .hud { top: 12px; left: 12px; font-size: 11.5px; padding: 8px 10px; }
@media (max-width: 400px) { .screen .hud .opt { display: none; } }
.ctrl { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; padding: 12px; border-top: 1px solid rgba(255, 255, 255, .07); background: #0d1116; }
.feed-hint { flex: 1 1 220px; margin: 0 4px; font: 400 12.5px/1.4 var(--mono); color: #8d949a; }
.chip-btn { min-height: 40px; padding: 0 16px; border-radius: 999px; border: 1px solid rgba(255, 255, 255, .2); background: transparent; color: #eceae4; font: 500 13px/1 var(--mono); cursor: pointer; }
.chip-btn:hover { border-color: var(--box); }
.chip-btn[aria-pressed="true"] { background: var(--box); border-color: var(--box); color: #07090c; }
.bands { display: flex; flex-wrap: wrap; gap: 8px; }
.sub { margin-top: 28px; padding: 26px; border: 1px dashed var(--rule); border-radius: 18px; }
.sub h3 { margin-bottom: 10px; }
.sub p { margin: 0; color: var(--ink2); max-width: 70ch; }

/* The mobile app card's demo (phone.js): the phone asks its API for a plan. */
.demo { display: flex; align-items: center; gap: 12px; margin-top: 20px; padding: 16px; border-radius: 14px; background: var(--feed); }
.phone { position: relative; flex: none; width: 88px; height: 168px; padding: 24px 9px 9px; border: 3px solid #2a3038; border-radius: 18px; background: #0d1116; cursor: pointer; overflow: hidden; }
.phone .notch { position: absolute; top: 7px; left: 50%; width: 28px; height: 5px; margin-left: -14px; border-radius: 3px; background: #2a3038; }
.phone .spin { position: absolute; top: 18px; left: 50%; width: 14px; height: 14px; margin-left: -7px; border: 2px solid var(--box); border-right-color: transparent; border-radius: 50%; opacity: 0; transition: opacity .2s; }
.phone .rows { display: grid; gap: 9px; transition: transform .3s ease; }
.phone .rows span { position: relative; height: 16px; border-radius: 4px; background: #1a1f24; overflow: hidden; }
.phone .rows span::after { content: ""; position: absolute; inset: 0 auto 0 0; width: 0; background: var(--box); transition: width .5s ease; }
.phone .rows span:nth-child(2)::after { transition-delay: .1s; } .phone .rows span:nth-child(3)::after { transition-delay: .2s; } .phone .rows span:nth-child(4)::after { transition-delay: .3s; }
.wire { position: relative; flex: 1; min-width: 36px; height: 2px; background: repeating-linear-gradient(90deg, #3a424b 0 6px, transparent 6px 12px); }
.wire .dot { position: absolute; top: -4px; left: 0; width: 10px; height: 10px; border-radius: 50%; background: var(--you); opacity: 0; }
.api { flex: none; display: grid; gap: 6px; padding: 10px 12px; border: 1px solid #2a3038; border-radius: 10px; font: 500 12px/1.2 var(--mono); color: #c9ccd0; text-align: center; }
.api b { font-weight: 500; color: #5d646b; }
.demo:not([data-state=""]) .spin { opacity: 1; animation: spin .8s linear infinite; }
.demo[data-state="done"] .spin { opacity: 0; animation: none; }
.demo[data-state="pull"] .rows { transform: translateY(18px); }
.demo[data-state="req"] .dot { opacity: 1; left: calc(100% - 10px); transition: left .6s ease-in-out; }
.demo[data-state="ok"] .dot { opacity: 1; left: calc(100% - 10px); }
.demo[data-state="res"] .dot { opacity: 1; left: 0; background: var(--box); transition: left .6s ease-in-out; }
.demo:is([data-state="ok"], [data-state="res"], [data-state="done"]) .api b { color: var(--box); }
.demo[data-state="done"] .rows span::after { width: 78%; }
.demo[data-state="done"] .rows span:nth-child(2)::after { width: 52%; }
.demo[data-state="done"] .rows span:nth-child(3)::after { width: 34%; }
.demo[data-state="done"] .rows span:nth-child(4)::after { width: 64%; }
@keyframes spin { to { transform: rotate(360deg); } }
@media (prefers-reduced-motion: reduce) { .demo *, .demo *::after { transition: none !important; animation: none !important; } }

/* Experience and education: one row each, dates on the left. */
.xp { list-style: none; margin: 0; padding: 0; }
.xp li { display: grid; grid-template-columns: 190px minmax(0, 1fr); gap: 4px 24px; padding: 18px 0; border-top: 1px solid var(--rule); }
.xp .when { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; margin: 0; font: 400 13.5px/1.7 var(--mono); color: var(--ink3); }
.xp h3 { font-size: 19px; line-height: 1.35; margin-bottom: 4px; }
.xp .as { font: 500 14px/1.4 var(--mono); color: var(--ink3); letter-spacing: 0; margin-left: 6px; }
.xp li p:not(.when) { margin: 0; color: var(--ink2); }
.xp-edu { margin-top: 48px; }
@media (max-width: 640px) { .xp li { grid-template-columns: 1fr; } .xp .as { display: block; margin: 4px 0 0; } }
.now { font: 500 11px/1 var(--mono); letter-spacing: .1em; text-transform: uppercase; padding: 5px 8px; border-radius: 999px; background: var(--accent); color: var(--accent-ink); }

/* Papers: each row opens the paper's page in a new tab. */
.pubs { list-style: none; margin: 0; padding: 0; counter-reset: pub; }
.pubs li { counter-increment: pub; display: grid; grid-template-columns: 44px minmax(0, 1fr); gap: 8px 16px; padding: 22px 0; border-top: 1px solid var(--rule); }
.pubs li::before { content: counter(pub, decimal-leading-zero); font: 500 14px/1.6 var(--mono); color: var(--accent); }
.pubs a { display: block; color: inherit; text-decoration: none; }
.pubs .t { display: block; font: 500 19px/1.4 var(--display); margin: 0 0 8px; }
.pubs a:hover .t { color: var(--accent); text-decoration: underline; text-underline-offset: 4px; }
.pubs .v { display: block; font: 400 13.5px/1.5 var(--mono); color: var(--ink3); }
.pubs .v b { font-weight: 500; color: var(--accent); }
.pubs .host { white-space: nowrap; color: var(--accent); margin-left: 6px; }

.contact { display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr); gap: clamp(32px, 6vw, 80px); padding-bottom: 40px; }
@media (max-width: 800px) { .contact { grid-template-columns: 1fr; } }
.contact > div > p { color: var(--ink2); }
.links { list-style: none; padding: 0; margin: 0; display: grid; gap: 10px; font: 500 15px/1.4 var(--mono); }
.links a { overflow-wrap: anywhere; }
.form { display: grid; gap: 8px; background: var(--panel); border: 1px solid var(--rule); border-radius: 18px; padding: clamp(22px, 4vw, 32px); }
.form label { font: 500 13px/1 var(--mono); letter-spacing: .04em; color: var(--ink2); margin-top: 8px; }
.form input, .form textarea { width: 100%; font: 16px/1.5 var(--body); color: var(--ink); background: var(--bg); border: 1px solid var(--rule); border-radius: 12px; padding: 12px 14px; }
.form textarea { resize: vertical; min-height: 140px; }
.form input:focus, .form textarea:focus { outline: 2px solid var(--accent); outline-offset: 1px; border-color: transparent; }
.form [aria-invalid="true"] { border-color: var(--out); }
.form .btn { margin-top: 14px; justify-self: start; }
.form .btn[disabled] { opacity: .6; cursor: progress; }
.status { margin: 6px 0 0; min-height: 1.6em; font-size: 15px; }
.status.ok { color: var(--accent); }
.status.err { color: var(--out); }

.foot { max-width: var(--wrap); margin: 64px auto 0; padding: 28px 24px calc(28px + env(safe-area-inset-bottom, 0px)); border-top: 1px solid var(--rule);
  display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px 24px; font: 400 13px/1.5 var(--mono); color: var(--ink3); }
.foot p { margin: 0; }
.foot a { color: inherit; }