/* ===========================================================
   arpitvaghela.github.io
   Shares the design system of the project pages: paper ground,
   Literata for prose, Inter for interface, periwinkle accent.
   =========================================================== */

:root {
  --paper:   #FFFAFA;
  --paper-2: #F9F0F0;
  --plate:   #FFFFFF;
  --ink:     #1C1B16;
  --ink-2:   #56544A;
  --ink-3:   #8C8A7E;
  --rule:      rgba(28, 27, 22, .16);
  --rule-soft: rgba(28, 27, 22, .085);

  /* Periwinkle in two steps of one hue. The tint only reaches 1.5:1 on the
     paper, so it fills behind dark text while the deeper step is the text. */
  --accent:      #4D4DD5;
  --accent-tint: #CCCCFF;

  --serif: "Literata", Georgia, "Times New Roman", serif;
  --sans:  "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;

  --gutter: clamp(20px, 5vw, 56px);
  --max:    1000px;
  --measure: 68ch;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--serif);
  font-size: 17px;
  line-height: 1.62;
  font-optical-sizing: auto;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
}

.wrap { max-width: var(--max); margin-inline: auto; padding-inline: var(--gutter); }

p { margin: 0 0 1em; }
p:last-child { margin-bottom: 0; }

a {
  color: var(--ink);
  text-decoration-color: rgba(77, 77, 213, .5);
  text-underline-offset: .2em;
  text-decoration-thickness: 1px;
  transition: color .16s ease, text-decoration-color .16s ease;
}
a:hover { color: var(--accent); text-decoration-color: var(--accent); }

:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; border-radius: 2px; }
strong, b { font-weight: 600; }

.skip { position: absolute; left: -9999px; top: 0; background: var(--accent); color: #fff; padding: 10px 18px; z-index: 200; }
.skip:focus { left: 12px; top: 12px; }

.icon { width: 1em; height: 1em; flex: none; fill: currentColor; }

/* --- nav ---------------------------------------------------- */

.nav {
  position: sticky; top: 0; z-index: 100;
  display: flex; align-items: center; gap: 16px;
  padding: 10px var(--gutter);
  background: rgba(255, 250, 250, .88);
  backdrop-filter: blur(12px) saturate(140%);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  border-bottom: 1px solid var(--rule-soft);
  font-family: var(--sans);
}
.nav__mark {
  display: flex; align-items: center; gap: 8px;
  font-weight: 600; font-size: 13.5px;
  text-decoration: none; white-space: nowrap; flex: none;
}
.nav__mark:hover { color: var(--ink); }
.nav__glyph { width: 22px; height: 22px; flex: none; }
.nav__links { margin-left: auto; display: flex; gap: 7px; flex: none; }

.pill {
  display: inline-flex; align-items: center; gap: 7px;
  padding: 7px 14px;
  border: 1px solid var(--rule);
  border-radius: 999px;
  font-family: var(--sans);
  font-size: 13.5px; font-weight: 500;
  text-decoration: none; color: var(--ink);
  background: transparent; white-space: nowrap;
  transition: border-color .16s ease, background .16s ease, color .16s ease;
}
.pill:hover { border-color: var(--accent); background: rgba(77, 77, 213, .08); color: var(--accent); }
.pill--primary { background: var(--accent-tint); border-color: var(--accent-tint); color: var(--ink); font-weight: 600; }
.pill--primary:hover { background: #AAAAFA; border-color: #AAAAFA; color: var(--ink); }
.pill--sm { padding: 5px 11px; font-size: 12.5px; gap: 6px; }

@media (max-width: 620px) {
  .nav__mark span { display: none; }
  /* four pills no longer fit a phone width: drop to icons only */
  .nav__links { gap: 6px; }
  .nav__links .pill { padding: 7px; }
  .nav__links .pill span { display: none; }
}

/* --- hero ---------------------------------------------------- */

.hero { padding: clamp(34px, 5vw, 62px) 0 clamp(30px, 4.4vw, 50px); }

.hero__grid {
  display: grid;
  grid-template-columns: 220px minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}
@media (max-width: 720px) {
  .hero__grid { grid-template-columns: 1fr; gap: 24px; }
  .portrait { max-width: 190px; }
}

.portrait {
  margin: 0;
  background: var(--plate);
  border: 1px solid var(--rule-soft);
  border-radius: 3px;
  padding: 6px;
}
.portrait img { display: block; width: 100%; height: auto; border-radius: 2px; }

/* Given name and surname stack on two lines: the surname steps in by 0.3em and
   up by three weights, so the pair reads as one name rather than two words. */
.hero__name {
  font-weight: 300;
  font-size: clamp(36px, 6vw, 64px);
  line-height: .9;
  letter-spacing: -.032em;
  margin: 0 0 clamp(14px, 2vw, 18px);
}
.hero__name span { display: block; }
.hero__name .hero__surname { margin-left: .3em; font-weight: 600; }

.hero__role {
  font-size: clamp(18px, 2.2vw, 21px);
  line-height: 1.3;
  letter-spacing: -.014em;
  margin: 0 0 2px;
}
.hero__affil {
  font-family: var(--sans);
  font-size: 14px; font-weight: 500;
  letter-spacing: -.002em;
  color: var(--ink-2);
  margin: 0 0 clamp(18px, 2.6vw, 22px);
}
.hero__bio {
  font-family: var(--sans);
  font-size: 15.5px; line-height: 1.6; letter-spacing: -.004em;
  color: var(--ink-2);
  max-width: var(--measure);
  margin-bottom: clamp(20px, 2.8vw, 26px);
}
.hero__bio p { margin-bottom: .8em; }
/* Research focus on a tint band — the same periwinkle as the primary pill, so it
   reads as a highlight rather than a link. box-decoration-break keeps the padding
   on both fragments when the phrase wraps. */
.hero__bio .hero__key {
  background: var(--accent-tint);
  color: var(--ink);
  font-weight: 600;
  padding: .08em .3em;
  margin: 0 -.08em;
  border-radius: 2px;
  box-decoration-break: clone;
  -webkit-box-decoration-break: clone;
}
.hero__bio p:last-child { margin-bottom: 0; }

/* Closing line washed from the tint into the accent. Falls back to solid accent
   where background-clip: text is unsupported. */
.hero__bio .hero__say {
  font-weight: 600;
  color: var(--accent);
  background-image: linear-gradient(96deg, var(--accent-tint) 0%, var(--accent) 72%);
  -webkit-background-clip: text;
          background-clip: text;
}
@supports (-webkit-background-clip: text) or (background-clip: text) {
  .hero__bio .hero__say { color: transparent; }
}

.actions { display: flex; flex-wrap: wrap; gap: 8px; }

/* --- sections ------------------------------------------------ */

.section { padding: clamp(34px, 4.6vw, 58px) 0; border-top: 1px solid var(--rule-soft); }
[id] { scroll-margin-top: 66px; }

.section__eyebrow {
  font-family: var(--sans);
  font-size: 13px; font-weight: 600; color: var(--accent);
  margin: 0 0 10px;
}
.section__title {
  font-weight: 400;
  font-size: clamp(28px, 3.8vw, 40px);
  line-height: 1.17;
  letter-spacing: -.018em;
  margin: 0 0 clamp(20px, 2.6vw, 30px);
}

/* --- publications -------------------------------------------- */

.pub {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  gap: clamp(18px, 2.8vw, 32px);
  padding: clamp(20px, 2.6vw, 28px) 0;
  border-top: 1px solid var(--rule-soft);
  align-items: start;
}
@media (max-width: 720px) {
  .pub { grid-template-columns: 1fr; gap: 14px; }
  .pub__media { max-width: 320px; }
}

.pub__media {
  margin: 0;
  background: var(--plate);
  border: 1px solid var(--rule-soft);
  border-radius: 3px;
  padding: 5px;
  overflow: hidden;
  position: relative;
}
.pub__media img, .pub__media video { display: block; width: 100%; height: auto; border-radius: 2px; }
.pub__media video { display: none; }
.pub__media.has-video:hover video { display: block; }
.pub__media.has-video:hover img { display: none; }

/* Stands in when an entry has no thumbnail. Drawn in CSS rather than SVG: the
   slot changes shape between breakpoints, and a fixed viewBox would letterbox
   itself into a small square on the wide mobile band. */
.pub__media--empty {
  /* Rule and label share one token, so they can never drift apart. */
  --ph: rgba(77, 77, 213, .3);
  position: relative;
  aspect-ratio: 4 / 3;
  padding: 0;
  background: transparent;
  border: 1.5px solid var(--ph);
}
.pub__media--empty span {
  position: absolute;
  right: 14px;
  bottom: 10px;
  font-family: var(--serif);
  font-weight: 700;
  font-size: 27.5px;   /* 1.25x */
  letter-spacing: -.012em;
  line-height: 1;
  color: var(--ph);
}
/* Stacked on a phone the 4:3 box becomes a large void; flatten it to a band. */
@media (max-width: 720px) {
  .pub__media--empty { aspect-ratio: 16 / 5; max-width: 100%; }
}

/* Title leads. Venue sits between it and the authors, underlined in the accent
   at regular weight. Authors are the lightest thing in the card. */
.pub__title {
  font-size: 20px;
  font-weight: 500;
  line-height: 1.26;
  letter-spacing: -.016em;
  margin: 0 0 7px;
}
.pub__venue {
  font-family: var(--sans);
  font-size: 12px; font-weight: 400;
  color: var(--accent);
  line-height: 1.5;
  margin: 0 0 5px;
}
/* Named, not a bare `span` -- that also matched the award badge sitting
   beside it and underlined the pill. */
.pub__venue-name {
  text-decoration: underline;
  text-decoration-color: rgba(77, 77, 213, .45);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}
.pub__award {
  display: inline-block;
  margin-left: 7px;
  padding: 1.5px 8px;
  border-radius: 999px;
  background: var(--accent);
  color: #fff;
  font-size: 10.5px; font-weight: 600;
  letter-spacing: .01em;
  text-decoration: none;
  vertical-align: 1px;
}

.pub__authors {
  font-family: var(--sans);
  font-size: 12px; line-height: 1.55;
  color: var(--ink-3);
  margin: 0;
}
.pub__authors a { color: var(--ink-3); text-decoration: none; }
.pub__authors a:hover { color: var(--accent); text-decoration: underline; }
.pub__authors .me { font-weight: 700; color: var(--ink); }

.pub__desc { font-size: 13.5px; color: var(--ink-2); margin: 8px 0 0; max-width: var(--measure); }
.pub__links { display: flex; flex-wrap: wrap; gap: 5px; margin-top: 9px; }

/* --- footer --------------------------------------------------- */

.foot {
  border-top: 1px solid var(--rule-soft);
  padding: 28px 0 44px;
  font-family: var(--sans);
  font-size: 13px; color: var(--ink-3);
}
.foot__links { display: flex; gap: 10px; margin-bottom: 16px; }
.foot__links a {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px;
  border: 1px solid var(--rule); border-radius: 999px;
  color: var(--ink); font-size: 15px;
  transition: border-color .16s ease, background .16s ease, color .16s ease;
}
.foot__links a:hover { border-color: var(--accent); background: rgba(77, 77, 213, .08); color: var(--accent); }

@media (max-width: 620px) { body { font-size: 16.5px; } }