/* ============================================================
   hkk.fyi — exactly three hues, everything else is a tint:
   paper (cream), ink (near-black), sig (smith-chart red)
   ============================================================ */
:root{
  --paper:#F4EFE4;
  --ink:#1C1B1A;
  --sig:#D9482B;
  --bg:var(--paper);
  --fg:var(--ink);
  --font-sans:"Space Grotesk",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"IBM Plex Mono",ui-monospace,"Cascadia Mono",Consolas,monospace;
  --maxw:1060px;
}
html.ink{ --bg:var(--ink); --fg:var(--paper); }

*,*::before,*::after{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
@media (prefers-reduced-motion: reduce){ html{ scroll-behavior:auto; } }

body{
  margin:0;
  background:var(--bg);
  color:var(--fg);
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
}

/* faint engineering-paper grid over the whole page */
body::before{
  content:"";
  position:fixed; inset:0;
  pointer-events:none;
  background-image:
    linear-gradient(color-mix(in srgb, var(--fg) 5%, transparent) 1px, transparent 1px),
    linear-gradient(90deg, color-mix(in srgb, var(--fg) 5%, transparent) 1px, transparent 1px);
  background-size:28px 28px;
  z-index:0;
}
body > *{ position:relative; z-index:1; }

::selection{ background:var(--sig); color:var(--paper); }

a{ color:inherit; text-decoration-color:var(--sig); text-decoration-thickness:2px; text-underline-offset:3px; }
a:hover{ color:var(--sig); }

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

.skip{
  position:absolute; left:-9999px; top:0;
  background:var(--sig); color:var(--paper);
  padding:.5rem 1rem; z-index:99; text-decoration:none;
}
.skip:focus{ left:0; }

.mono-label{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.14em;
  text-transform:uppercase;
  opacity:.88;
}

/* ================= topbar ================= */
.topbar{
  position:sticky; top:0; z-index:50;
  display:flex; align-items:center; gap:1.4rem;
  max-width:var(--maxw); margin:0 auto;
  padding:.7rem 1.2rem;
  background:color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter:blur(8px);
  border-bottom:1px solid color-mix(in srgb, var(--fg) 18%, transparent);
}
.brand{ display:flex; align-items:center; gap:.55rem; text-decoration:none; }
.brand-name{ font-weight:700; font-size:1.05rem; letter-spacing:.02em; }
.brand .dim{ opacity:.65; font-weight:400; }
.nav{ display:flex; gap:1.1rem; margin-left:auto; flex-wrap:wrap; }
.nav a{
  font-family:var(--font-mono); font-size:.8rem; letter-spacing:.08em; text-transform:uppercase;
  text-decoration:none; padding:.2rem 0;
  border-bottom:2px solid transparent;
}
.nav a:hover{ color:var(--sig); }
.nav a.active{ border-bottom-color:var(--sig); color:var(--sig); }
.theme-btn{
  display:inline-flex; align-items:center; justify-content:center;
  width:38px; height:34px; flex:none;
  background:none; border:1.5px solid var(--fg); color:var(--fg);
  padding:0; cursor:pointer; border-radius:5px;
}
.theme-btn svg{ width:18px; height:18px; }
.theme-btn:hover{ border-color:var(--sig); color:var(--sig); }
html.ink .theme-paper{ display:none; }
html:not(.ink) .theme-ink{ display:none; }

/* generic hover tooltip — attaches ONLY to the element carrying .tip (e.g. the ".fyi" span) */
.tip{ position:relative; cursor:help; }
.tip:hover{ color:var(--sig); }
.tip::after{
  content:attr(data-tip);
  position:absolute; top:calc(100% + 9px); left:50%; transform:translateX(-50%) translateY(4px);
  font-family:var(--font-mono); font-size:.68rem; letter-spacing:.06em; text-transform:none;
  white-space:nowrap; padding:.38rem .65rem;
  background:var(--fg); color:var(--bg); border-radius:5px;
  box-shadow:0 8px 22px rgba(0,0,0,.25);
  opacity:0; pointer-events:none; transition:opacity .16s ease, transform .16s ease;
  z-index:80;
}
.tip::before{
  content:""; position:absolute; top:calc(100% + 1px); left:50%;
  transform:translateX(-50%) translateY(4px);
  border:5px solid transparent; border-bottom-color:var(--fg);
  opacity:0; pointer-events:none; transition:opacity .16s ease, transform .16s ease;
  z-index:80;
}
.tip:hover::after, .brand:focus-visible .tip::after{ opacity:1; transform:translateX(-50%) translateY(0); }
.tip:hover::before, .brand:focus-visible .tip::before{ opacity:1; transform:translateX(-50%) translateY(0); }

/* ================= layout ================= */
main{ max-width:var(--maxw); margin:0 auto; padding:0 1.2rem; }
.section{ padding:4.2rem 0 1rem; scroll-margin-top:4.5rem; }
.section-intro{ max-width:56ch; opacity:.85; margin-top:.2rem; }

/* section headings: 01 · Name ——[symbol]—— */
.section h2{
  display:flex; align-items:center; gap:.7rem;
  font-size:1.9rem; font-weight:700; letter-spacing:.01em;
  margin:0 0 1.8rem;
}
.secnum{
  font-family:var(--font-mono); font-weight:500; font-size:1.1rem;
  color:var(--sig);
}
.secsym{ width:32px; height:19px; opacity:.75; flex:none; }
.secrule{ flex:1; height:1px; background:color-mix(in srgb, var(--fg) 25%, transparent); }

/* opaque so the page grid never shows through elements */
.card{
  border:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  border-radius:6px;
  background:color-mix(in srgb, var(--bg) 96%, var(--fg));
}

/* ================= hero ================= */
.hero{
  position:relative;
  padding:5.2rem 0 2.2rem;
  overflow:hidden;
}
.hero h1{
  font-size:clamp(2.6rem, 7vw, 4.6rem);
  line-height:1.04; letter-spacing:-.02em;
  margin:0 0 1.2rem; font-weight:700;
  position:relative;
}
.lede{ max-width:58ch; font-size:1.05rem; margin:0 0 1.05rem; position:relative; }

.hero-grid{
  display:grid; grid-template-columns:1.75fr 1fr; gap:2.6rem;
  align-items:center; position:relative;
}
.hero-grid .portrait{ justify-self:end; width:100%; }

/* standing wave */
.wave{ margin:1.6rem 0 0; position:relative; }
#waveSvg{ width:100%; height:130px; display:block; cursor:crosshair; }
.wave-env{ stroke:color-mix(in srgb, var(--sig) 45%, transparent); stroke-width:1.2; fill:none; stroke-dasharray:5 6; }
.wave-line{ stroke:var(--sig); stroke-width:2.4; fill:none; stroke-linecap:round; }
.wave-axis{ stroke:color-mix(in srgb, var(--fg) 30%, transparent); stroke-width:1; }
.wave-node{ fill:var(--fg); opacity:.5; }

/* ================= portrait ================= */
.portrait{
  position:relative; margin:0; max-width:340px;
  border:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  border-radius:6px; overflow:hidden;
  background:color-mix(in srgb, var(--fg) 6%, transparent);
}
.portrait img{ display:block; width:100%; aspect-ratio:1/1; object-fit:cover; }
.portrait-mono{
  display:none; aspect-ratio:1/1; align-items:center; justify-content:center;
  font-family:var(--font-mono); font-weight:700; font-size:4.5rem; color:var(--sig);
  letter-spacing:.05em;
}
.portrait.noimg img{ display:none; }
.portrait.noimg .portrait-mono{ display:flex; }
.portrait figcaption{
  position:absolute; left:0; right:0; bottom:0;
  padding:.5rem .7rem; opacity:1;
  color:var(--paper); background:linear-gradient(transparent, rgba(28,27,26,.82));
}
.portrait.noimg figcaption{ position:static; background:none; color:var(--fg); border-top:1px dashed color-mix(in srgb, var(--fg) 25%, transparent); }

/* ============ hover cards — UT, Smith chart, DBS, ICEE… ============ */
.hcard-link{
  position:relative; color:inherit; text-decoration:none;
  border-bottom:1px dashed color-mix(in srgb, var(--sig) 70%, transparent);
  white-space:nowrap; cursor:help;
}
.hcard-link:hover{ color:var(--sig); }
.hcard{
  position:absolute; left:0; top:calc(100% + 12px);
  width:300px; max-width:calc(100vw - 3rem);
  padding:14px 15px;
  display:grid; grid-template-columns:auto 1fr; gap:13px; align-items:center;
  background:var(--bg); color:var(--fg);
  font-family:var(--font-sans); font-weight:400; font-style:normal;
  white-space:normal; text-align:left;
  border:1.5px solid var(--fg); border-radius:9px;
  box-shadow:0 14px 34px rgba(0,0,0,.28);
  opacity:0; transform:translateY(6px); pointer-events:none;
  transition:opacity .18s ease, transform .18s ease; z-index:70;
  text-transform:none; letter-spacing:normal;
}
.hcard-link:hover .hcard, .hcard-link:focus-visible .hcard{ opacity:1; transform:translateY(0); }
.hcard::after{
  content:""; position:absolute; bottom:100%; left:34px;
  border:7px solid transparent; border-bottom-color:var(--fg);
}
.hcard.flip{ left:auto; right:0; }
.hcard.flip::after{ left:auto; right:34px; }
/* photo variant (University of Tehran) — image bleeds to the card edges */
.hcard.uni-card{ width:330px; grid-template-columns:1fr; gap:0; padding:0 0 14px; }
.hcard-img{
  display:block; width:100%; height:150px; object-fit:cover;
  border-radius:7.5px 7.5px 0 0;
  border-bottom:1.5px solid var(--fg);
  margin-bottom:11px;
}
.uni-card .hcard-body{ padding:0 15px; }

.hcard-icon{ width:58px; height:auto; flex:none; }
.hcard-icon .hc-fg{ fill:none; stroke:var(--fg); stroke-width:2.6; stroke-linecap:round; stroke-linejoin:round; }
.hcard-icon .hc-sig{ fill:none; stroke:var(--sig); stroke-width:2.6; stroke-linecap:round; stroke-linejoin:round; }
.uni-blade{ fill:none; stroke:var(--sig); stroke-width:7; stroke-linecap:round; }
.uni-ground{ fill:none; stroke:var(--fg); stroke-width:2.4; stroke-linecap:round; }
.uni-emblem{ fill:var(--sig); }
.hcard-body b{ font-weight:700; }
.hcard-body > b{ display:block; font-size:.98rem; margin-bottom:3px; }
.hcard-facts{ display:block; font-size:.76rem; opacity:.85; line-height:1.5; }
.hcard-more{ display:inline-block; margin-top:7px; font-family:var(--font-mono); font-size:.7rem; color:var(--sig); }

/* ================= lab ================= */
.project{
  display:grid; grid-template-columns:1.15fr 1fr;
  margin-top:1.6rem; /* no overflow:hidden — hover cards must escape */
}
.project-preview{
  position:relative; aspect-ratio:16/10; min-height:280px;
  border-right:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  background:var(--ink);
  overflow:hidden; border-radius:4.5px 0 0 4.5px;
}
.project-preview iframe{
  width:200%; height:200%;
  transform:scale(.5); transform-origin:0 0;
  border:0; pointer-events:none;
}
.preview-hit{
  position:absolute; inset:0;
  background:transparent; border:0; cursor:pointer;
  display:flex; align-items:flex-end; justify-content:flex-start;
  padding:1rem;
}
.preview-hit .mono-label{
  background:var(--sig); color:var(--paper); opacity:1;
  padding:.45rem .9rem; border-radius:3px;
  transition:transform .15s ease;
}
.preview-hit:hover .mono-label{ transform:scale(1.06); }
.project-info{ padding:1.5rem 1.6rem; }
.project-info h3{ margin:0 0 .3rem; font-size:1.35rem; }
.proj-tags{ color:var(--sig); opacity:1; margin:0 0 .8rem; }
.project-info p{ margin:0 0 1.1rem; }

.btn-row{ display:flex; gap:.6rem; flex-wrap:wrap; }
.btn{
  font-family:var(--font-mono); font-size:.8rem; letter-spacing:.05em;
  border:1.5px solid var(--fg); color:var(--fg); background:none;
  padding:.5rem 1rem; border-radius:3px; cursor:pointer;
  text-decoration:none; display:inline-block;
}
.btn:hover{ border-color:var(--sig); color:var(--sig); }
.btn.solid{
  background:var(--sig); border-color:var(--sig); color:var(--paper);
}
.btn.solid:hover{ background:color-mix(in srgb, var(--sig) 85%, var(--ink)); color:var(--paper); }

.project-slot{
  margin-top:1.2rem; padding:1.4rem 1.6rem;
  border-style:dashed;
  opacity:.8;
}
.project-slot p{ margin:.2rem 0; }

/* ================= cv ================= */
.cv-head{
  display:flex; align-items:center; justify-content:space-between; gap:1rem;
  flex-wrap:wrap;
  border:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  border-radius:6px 6px 0 0;
  padding:.7rem 1.2rem;
  background:color-mix(in srgb, var(--bg) 93%, var(--fg));
}
.cv-block{
  border:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  border-top:0;
  padding:1.3rem 1.4rem;
  background:var(--bg);
}
.cv-block:last-of-type{ border-radius:0 0 6px 6px; }
.cv-title{
  font-family:var(--font-mono); font-size:1.02rem; font-weight:700;
  letter-spacing:.1em; text-transform:uppercase;
  color:var(--fg); margin:0 0 1rem;
  display:flex; align-items:center; gap:.65rem;
  padding:.6rem .8rem;
  border-radius:5px;
  background:color-mix(in srgb, var(--fg) 9%, var(--bg));
}
.cv-title::before{
  content:""; width:12px; height:12px; flex:none;
  background:var(--sig); border-radius:2px;
}
/* collapsible CV blocks */
.cv-fold summary.cv-title{ cursor:pointer; list-style:none; }
.cv-fold summary.cv-title::-webkit-details-marker{ display:none; }
.cv-fold summary.cv-title:hover{ color:var(--sig); background:color-mix(in srgb, var(--fg) 14%, var(--bg)); }
.cv-fold:not([open]) summary.cv-title{ margin-bottom:0; }
.fold-hint{ margin-left:auto; color:var(--sig); transition:transform .2s ease; }
.cv-fold[open] > summary .fold-hint{ transform:rotate(180deg); }
.cv-head-actions{ display:flex; gap:.5rem; flex-wrap:wrap; }
.cv-entry > p{ margin:.4rem 0; }
.cv-row{ display:flex; justify-content:space-between; gap:1rem; align-items:baseline; flex-wrap:wrap; }
.cv-sub{ opacity:.8; font-size:.92rem; margin:.15rem 0 0; }
.cv-when{ font-family:var(--font-mono); font-size:.78rem; white-space:nowrap; opacity:.85; }
.cv-list{ margin:.4rem 0 0; padding-left:1.2rem; }
.cv-list.plain{ list-style:none; padding-left:0; }
.cv-list li{ margin:.4rem 0; }
.cv-list li::marker{ color:var(--sig); }

.courses{ margin-top:.8rem; }
.courses summary{ cursor:pointer; list-style:none; }
.courses summary::-webkit-details-marker{ display:none; }
.courses summary:hover{ color:var(--sig); opacity:1; }
.course-grid{
  display:grid; grid-template-columns:repeat(auto-fill, minmax(220px,1fr));
  gap:.25rem .9rem; list-style:none; margin:.8rem 0 .5rem; padding:0;
  font-size:.92rem;
}
.course-grid li{
  display:flex; justify-content:space-between; gap:.6rem;
  border-bottom:1px dashed color-mix(in srgb, var(--fg) 25%, transparent);
  padding:.22rem 0;
}
.course-grid b{ font-family:var(--font-mono); font-weight:500; color:var(--sig); }

.pub-list{ margin:0; padding-left:1.2rem; }
.pub-list li{ margin:.7rem 0; }
.pub-list li::marker{ color:var(--sig); font-weight:700; }
.pub-note{
  font-family:var(--font-mono); font-size:.7rem; letter-spacing:.08em; text-transform:uppercase;
  color:var(--sig); white-space:nowrap;
}

.cv-table{ width:100%; border-collapse:collapse; }
.cv-table td{
  padding:.5rem .6rem .5rem 0;
  border-bottom:1px dashed color-mix(in srgb, var(--fg) 25%, transparent);
  vertical-align:baseline;
}
.cv-table tr:last-child td{ border-bottom:0; }

.chips{ display:flex; flex-wrap:wrap; gap:.45rem; }
.chip{
  font-family:var(--font-mono); font-size:.78rem;
  border:1.5px solid color-mix(in srgb, var(--fg) 40%, transparent);
  padding:.28rem .7rem; border-radius:99px;
  display:inline-flex; align-items:center; gap:.42rem;
}
.sk{
  width:15px; height:15px; flex:none;
  stroke:currentColor; fill:none;
  stroke-width:1.7; stroke-linecap:round; stroke-linejoin:round;
}
.sk .f{ fill:currentColor; stroke:none; }
.chip.solid{ border-color:var(--sig); color:var(--sig); }

/* ================= contact ================= */
.ports{ display:grid; grid-template-columns:repeat(auto-fit, minmax(300px,1fr)); gap:1rem; margin-top:1.4rem; }
.port{
  padding:1.1rem 1.2rem; text-decoration:none;
  display:grid; grid-template-columns:auto 1fr; align-items:center; gap:.9rem;
  transition:transform .15s ease, border-color .15s ease;
}
.port:hover{ transform:translateY(-3px); border-color:var(--sig); color:inherit; }
.port:hover .port-val{ color:var(--sig); }
.port .mono-label{ color:var(--sig); opacity:1; }
.port-ic{ color:var(--sig); display:flex; align-items:center; }
.port-ic svg{ width:26px; height:26px; }
.port-body{ display:flex; flex-direction:column; gap:.35rem; min-width:0; }
.port-val{
  font-size:.95rem; font-weight:500;
  white-space:nowrap; overflow:hidden; text-overflow:ellipsis;
}

/* ================= footer ================= */
.footer{
  max-width:var(--maxw); margin:4rem auto 0;
  padding:1.4rem 1.2rem 2.2rem;
  border-top:1px solid color-mix(in srgb, var(--fg) 18%, transparent);
  display:flex; justify-content:space-between; gap:1rem; flex-wrap:wrap;
  font-size:.9rem;
}
.footer-love{ font-size:.9rem; opacity:.8; }
.footer-love .heart{ color:var(--sig); font-style:normal; }

/* ================= launcher dialog ================= */
#launcher{
  width:min(1280px, 96vw); height:92vh;
  padding:0; border:2px solid var(--fg); border-radius:8px;
  background:var(--bg); color:var(--fg);
  display:none; flex-direction:column; overflow:hidden;
}
#launcher[open]{ display:flex; }
#launcher::backdrop{ background:rgba(28,27,26,.72); backdrop-filter:blur(3px); }
.launcher-bar{
  display:flex; align-items:center; justify-content:space-between; gap:1rem;
  padding:.55rem .9rem;
  border-bottom:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent);
  background:color-mix(in srgb, var(--fg) 5%, transparent);
}
.launcher-actions{ display:flex; gap:.5rem; }
#launcherFrame{ flex:1; border:0; width:100%; background:var(--paper); }

/* small red labels get a lighter tint on the dark theme for legibility
   (still a mix of the same three hues) */
html.ink .secnum,
html.ink .proj-tags,
html.ink .pub-note,
html.ink .port .mono-label,
html.ink .course-grid b,
html.ink .hcard-more,
html.ink .fold-hint{
  color:color-mix(in srgb, var(--sig) 72%, var(--paper));
}
html.ink .chip.solid{
  color:color-mix(in srgb, var(--sig) 72%, var(--paper));
  border-color:color-mix(in srgb, var(--sig) 72%, var(--paper));
}

/* ================= responsive ================= */
@media (max-width: 860px){
  .section{ padding:5.4rem 0 1.4rem; }
  .hero{ padding-top:3.6rem; }
  /* photo tucks up beside the title; paragraphs run full width below */
  .hero-grid{
    grid-template-columns:1fr minmax(120px, 38%);
    grid-template-areas:
      "title photo"
      "body  body";
    column-gap:1.4rem; row-gap:1.6rem;
    align-items:center;
  }
  .hero-text{ display:contents; }
  .hero-text > h1{ grid-area:title; margin-bottom:0; }
  .hero-body{ grid-area:body; }
  .hero-grid .portrait{ grid-area:photo; justify-self:end; align-self:center; max-width:100%; margin:0; }
  .project{ grid-template-columns:1fr; }
  .project-preview{ border-right:0; border-bottom:1.5px solid color-mix(in srgb, var(--fg) 30%, transparent); }
  .topbar{ gap:.8rem; }
  .nav{ gap:.8rem; }
  .project-preview{ border-radius:4.5px 4.5px 0 0; }
}
@media (max-width: 560px){
  body{ font-size:16px; }
  .cv-table td:nth-child(2){ display:none; } /* drop professor column on tiny screens */
  .brand-name{ display:none; }
  .hero h1{ font-size:clamp(2rem, 10vw, 2.8rem); }
  .hero-grid{ column-gap:1rem; }
  .portrait figcaption{ display:none; } /* photo is too small for the caption here */
}
@media (max-width: 400px){
  .port-val{ font-size:.84rem; }
}

/* ================= print: only the CV, in ink on paper ================= */
@media print{
  :root, html.ink{ --bg:#fff; --fg:#000; }
  body::before{ display:none; }
  .topbar, .hero, #lab, #contact, .footer, .cv-head-actions, #launcher{ display:none !important; }
  .cv-title{ background:none; border-bottom:1.5px solid #000; border-radius:0; padding:.2rem 0 .35rem; }
  .section{ padding:0; }
  #cv h2 .secrule{ display:none; }
  #cv{ font-size:12px; }
  .courses summary{ display:none; } /* site.js opens every <details> on beforeprint */
  #cv .fold-hint{ display:none; }
  .cv-table td:nth-child(2){ display:table-cell; }
  .hcard{ display:none; }
  .hcard-link{ border-bottom:0; }
  a{ text-decoration:none; }
}