/* ---------------------------------------------------------------
   Medha Hira — site styles

   Theming has three states:
     - no data-theme attribute  -> follow the OS (prefers-color-scheme)
     - data-theme="light"       -> forced light, even if the OS is dark
     - data-theme="dark"        -> forced dark, even if the OS is light
   The light palette is the base on bare :root so no colour is ever
   defined only inside a media query. Dark tokens are declared twice:
   once for the system default and once for the explicit override.
   --------------------------------------------------------------- */

:root {
  color-scheme: light;
  --bg: #fefdf9;
  --header-bg: rgba(254, 253, 249, 0.86);
  --ink: #253342;
  --heading: #2a3545;
  --accent: #1a3a5c;
  --text: #5c6a79;
  --muted: #87919c;
  --line: rgba(39, 55, 70, 0.105);
  --rule: rgba(39, 55, 70, 0.28);
  --link: #244e76;
  --nav-link: #4f5d6b;
  --chip-bg: rgba(229, 239, 248, 0.62);
  --chip-stroke: #86abdd;
  --code-bg: rgba(39, 55, 70, 0.06);
  --portrait-ring: rgba(255, 255, 255, 0.92);
  --portrait-shadow: rgba(41, 58, 72, 0.14);

  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, Georgia, serif;
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

/* Dark palette — system default (unless light is explicitly forced). */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    color-scheme: dark;
    --bg: #14181d;
    --header-bg: rgba(20, 24, 29, 0.86);
    --ink: #e3e9f0;
    --heading: #edf1f6;
    --accent: #a9c8ee;
    --text: #a6b2bf;
    --muted: #7d8894;
    --line: rgba(200, 215, 230, 0.13);
    --rule: rgba(200, 215, 230, 0.3);
    --link: #8ab4e8;
    --nav-link: #aab6c3;
    --chip-bg: rgba(120, 160, 210, 0.14);
    --chip-stroke: #7ba3d6;
    --code-bg: rgba(200, 215, 230, 0.09);
    --portrait-ring: rgba(255, 255, 255, 0.14);
    --portrait-shadow: rgba(0, 0, 0, 0.5);
  }
}

/* Dark palette — explicitly chosen via the header toggle. */
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #14181d;
  --header-bg: rgba(20, 24, 29, 0.86);
  --ink: #e3e9f0;
  --heading: #edf1f6;
  --accent: #a9c8ee;
  --text: #a6b2bf;
  --muted: #7d8894;
  --line: rgba(200, 215, 230, 0.13);
  --rule: rgba(200, 215, 230, 0.3);
  --link: #8ab4e8;
  --nav-link: #aab6c3;
  --chip-bg: rgba(120, 160, 210, 0.14);
  --chip-stroke: #7ba3d6;
  --code-bg: rgba(200, 215, 230, 0.09);
  --portrait-ring: rgba(255, 255, 255, 0.14);
  --portrait-shadow: rgba(0, 0, 0, 0.5);
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  line-height: 1.6;
  text-rendering: optimizeLegibility;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--link); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 0.16em; }

img { max-width: 100%; }

/* --- Header ---------------------------------------------------- */

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: var(--header-bg);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--line);
}

.header-inner,
.hero-inner,
.section,
.footer,
.page-shell {
  width: min(1240px, calc(100% - 56px));
  margin: 0 auto;
}

.header-inner {
  min-height: 74px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
}

.brand {
  color: var(--ink);
  font-family: var(--serif);
  font-size: 1.82rem;
  letter-spacing: -0.035em;
}
.brand:hover { text-decoration: none; }

.nav {
  display: flex;
  align-items: center;
  gap: 11px;
  font-size: 0.98rem;
  text-transform: lowercase;
}

.nav a { color: var(--nav-link); }
.nav-sep { color: var(--muted); opacity: 0.7; }

/* --- Theme toggle ----------------------------------------------- */

.theme-toggle {
  display: inline-flex;
  align-items: center;
  flex: none;
  margin-left: 4px;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--rule);
  border-radius: 999px;
  background: transparent;
  color: var(--nav-link);
  font: inherit;
  font-size: 0.95rem;
  line-height: 1;
  text-transform: lowercase;
  cursor: pointer;
  transition: border-color 160ms ease, color 160ms ease, background 160ms ease;
}

.theme-toggle:hover {
  border-color: var(--link);
  color: var(--link);
  background: var(--chip-bg);
}

.theme-toggle:focus-visible {
  outline: 2px solid var(--link);
  outline-offset: 2px;
}

.tt-face {
  display: inline-flex;
  align-items: center;
  gap: 0.4em;
}

.theme-toggle svg {
  width: 15px;
  height: 15px;
  flex: none;
  fill: none;
  stroke: currentColor;
  stroke-width: 1.7;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Show the face for the mode the button switches TO: a moon reading "dark"
   while light, a sun reading "light" while dark. Mirrors the token logic. */
.tt-to-light { display: none; }

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .tt-to-light { display: inline-flex; }
  :root:not([data-theme="light"]) .tt-to-dark { display: none; }
}

:root[data-theme="dark"] .tt-to-light { display: inline-flex; }
:root[data-theme="dark"] .tt-to-dark { display: none; }

:root[data-theme="light"] .tt-to-light { display: none; }
:root[data-theme="light"] .tt-to-dark { display: inline-flex; }

/* --- Hero ------------------------------------------------------ */

.hero {
  position: relative;
  border-bottom: 1px solid var(--line);
}

.hero-inner {
  padding-top: 78px;
  padding-bottom: 72px;
  max-width: 860px;
  margin-left: auto;
  margin-right: auto;
}

.identity-row {
  display: grid;
  grid-template-columns: 204px 1fr;
  gap: 28px;
  align-items: start;
  margin-bottom: 30px;
}

.portrait {
  width: 204px;
  height: 204px;
  display: block;
  object-fit: cover;
  object-position: 50% 30%;
  border-radius: 50%;
  border: 5px solid var(--portrait-ring);
  box-shadow: 0 18px 42px var(--portrait-shadow);
}

.identity-text { padding-top: 10px; }

h1,
.section-label,
.section-head h2,
.page-head h1 {
  font-family: var(--serif);
  font-weight: 400;
  letter-spacing: -0.045em;
  color: var(--heading);
}

.identity-text h1 {
  margin: 0 0 14px;
  font-size: clamp(2.7rem, 4vw, 4.1rem);
  line-height: 0.98;
}

.email-line {
  display: inline-block;
  color: var(--link);
  font-size: 1.03rem;
  margin-bottom: 6px;
}

.identity-links {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  color: var(--muted);
  font-size: 0.94rem;
  line-height: 1.4;
}

.identity-links-row {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.hero-lead {
  margin: 0 0 17px;
  color: var(--ink);
  font-size: 1.19rem;
  line-height: 1.54;
}

.hero-note {
  margin: 0;
  color: var(--text);
  font-size: 1.04rem;
}

/* --- Sections -------------------------------------------------- */

.section {
  display: grid;
  grid-template-columns: 220px 1fr;
  gap: 60px;
  padding: 84px 0;
  border-bottom: 1px solid var(--line);
}

.section-label {
  font-size: 3.05rem;
  line-height: 1;
}

.section-body {
  max-width: 760px;
  padding-left: 44px;
  border-left: 1px solid var(--line);
  color: var(--text);
  font-size: 1.18rem;
}

.section-body > :first-child { margin-top: 0; }
.section-body > :last-child { margin-bottom: 0; }
.section-body p { margin: 0 0 1.35rem; }

/* --- News ------------------------------------------------------ */

.news-list {
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 1.02rem;
}

.news-list li {
  display: grid;
  grid-template-columns: 150px 1fr;
  gap: 18px;
  padding: 13px 0;
  border-top: 1px solid var(--line);
}

.news-list li:first-child { border-top: 0; padding-top: 0; }

.news-date {
  color: var(--muted);
  font-size: 0.95rem;
  font-variant-numeric: tabular-nums;
  padding-top: 0.15em;
}

.news-text { color: var(--text); }

/* --- Publications ---------------------------------------------- */

.publications { display: block; }

.section-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 26px;
}

.section-head h2 {
  margin: 0;
  font-size: 3.05rem;
  line-height: 1;
}

.view-all {
  color: var(--link);
  font-size: 1rem;
  white-space: nowrap;
}

.pub-list { margin-top: 10px; }

.pub-item {
  display: grid;
  grid-template-columns: 70px 1fr auto;
  gap: 26px;
  align-items: center;
  padding: 26px 0;
  border-top: 1px solid var(--line);
}

.pub-icon {
  width: 50px;
  height: 50px;
  display: grid;
  place-items: center;
  border-radius: 999px;
  background: var(--chip-bg);
}

.pub-icon svg {
  width: 24px;
  height: 24px;
  fill: none;
  stroke: var(--chip-stroke);
  stroke-width: 1.6;
  stroke-linecap: round;
  stroke-linejoin: round;
}

/* Compound selectors here so these win over the generic .prose rules
   below when a publication list is rendered inside a .prose block. */
.pub-item .pub-main h3 {
  margin: 0 0 5px;
  font-family: var(--serif);
  font-size: 1.72rem;
  font-weight: 400;
  line-height: 1.14;
  letter-spacing: -0.03em;
  color: var(--heading);
}

.pub-item .pub-main h3 a { color: inherit; }
.pub-item .pub-main h3 a:hover { color: var(--link); }

.pub-item .pub-main p {
  margin: 0 0 4px;
  color: var(--text);
  font-size: 1rem;
}

.pub-item .pub-main span {
  color: var(--muted);
  font-size: 0.98rem;
  font-style: italic;
}

.pub-links {
  display: flex;
  gap: 10px;
  font-size: 1rem;
  white-space: nowrap;
}

/* --- Inner pages ----------------------------------------------- */

.page-shell {
  max-width: 900px;
  padding: 64px 0 80px;
}

.page-head { margin-bottom: 34px; }

.page-head h1 {
  margin: 0;
  font-size: clamp(2.4rem, 5vw, 3.4rem);
  line-height: 1;
}

.page-subtitle {
  margin: 12px 0 0;
  color: var(--text);
  font-size: 1.1rem;
}

.pdf-button {
  display: inline-flex;
  align-items: center;
  margin-top: 18px;
  border: 1px solid var(--line);
  border-radius: 999px;
  padding: 0.48rem 0.95rem;
  color: var(--accent);
  font-size: 0.95rem;
}
.pdf-button:hover {
  text-decoration: none;
  border-color: var(--rule);
}

/* --- Prose (markdown body copy) -------------------------------- */

.prose {
  color: var(--text);
  font-size: 1.05rem;
  line-height: 1.7;
}

.prose > :first-child { margin-top: 0; }
.prose > :last-child { margin-bottom: 0; }

.prose h1 {
  margin: 52px 0 14px;
  padding-bottom: 7px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.85rem;
  letter-spacing: -0.03em;
  color: var(--heading);
  border-bottom: 1px solid var(--line);
}

.prose h2 {
  margin: 40px 0 12px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.5rem;
  letter-spacing: -0.022em;
  color: var(--heading);
}

.prose h3 {
  margin: 30px 0 8px;
  font-family: var(--serif);
  font-weight: 400;
  font-size: 1.28rem;
  letter-spacing: -0.015em;
  color: var(--heading);
}

.prose p { margin: 0 0 1.05rem; }

.prose ul,
.prose ol {
  margin: 0 0 1.1rem;
  padding-left: 1.4rem;
}

.prose li { margin-bottom: 0.45rem; }
.prose li:last-child { margin-bottom: 0; }
.prose ul ul,
.prose ol ol,
.prose ul ol,
.prose ol ul { margin: 0.45rem 0 0.2rem; }

.prose li::marker { color: var(--muted); }

.prose strong { color: var(--ink); font-weight: 600; }

.prose hr {
  margin: 34px 0;
  border: 0;
  border-top: 1px solid var(--line);
}

.prose blockquote {
  margin: 24px 0;
  padding: 12px 18px;
  border-left: 3px solid var(--rule);
  color: var(--text);
}

.prose code {
  background: var(--code-bg);
  border-radius: 3px;
  padding: 0.06em 0.32em;
  font-family: var(--mono);
  font-size: 0.92em;
}

.prose pre {
  overflow-x: auto;
  padding: 12px 14px;
  background: var(--code-bg);
  border: 1px solid var(--line);
  border-radius: 4px;
  font-family: var(--mono);
  font-size: 0.85rem;
}
.prose pre code { background: none; padding: 0; }

.prose table {
  width: 100%;
  border-collapse: collapse;
  margin: 0 0 1.2rem;
  font-size: 0.98rem;
}
.prose th,
.prose td {
  text-align: left;
  padding: 0.5rem 0.6rem;
  border-bottom: 1px solid var(--line);
}

/* Wide content must scroll inside itself, never the page. */
.prose .table-wrap { overflow-x: auto; }

/* The About block is a .section-body that is also .prose; keep the larger
   section type scale rather than the smaller inner-page prose scale. */
.section-body.prose { font-size: 1.18rem; }
.section-body.prose p { margin: 0 0 1.35rem; }

/* --- Footer ---------------------------------------------------- */

.footer {
  display: flex;
  justify-content: space-between;
  gap: 20px;
  padding: 34px 0 46px;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.footer p { margin: 0; }

/* --- Scroll-in animation (progressive enhancement) --------------
   Gated on .anim, which the script adds only when it will actually
   run. Kept separate from .js so the theme toggle never depends on
   whether animations are enabled. */

.anim [data-animate] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 700ms ease, transform 700ms ease;
}

.anim [data-animate].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive ------------------------------------------------ */

@media (max-width: 1080px) {
  .section {
    grid-template-columns: 1fr;
    gap: 26px;
    padding: 64px 0;
  }

  .section-body {
    padding-left: 0;
    border-left: 0;
  }
}

@media (max-width: 760px) {
  .header-inner,
  .hero-inner,
  .section,
  .footer,
  .page-shell {
    width: min(100% - 28px, 1240px);
  }

  .header-inner {
    min-height: 66px;
    flex-direction: column;
    align-items: flex-start;
    justify-content: center;
    padding: 12px 0;
    gap: 4px;
  }

  .brand { font-size: 1.6rem; }

  .nav {
    gap: 7px;
    flex-wrap: wrap;
    font-size: 0.93rem;
  }

  .hero-inner {
    padding-top: 42px;
    padding-bottom: 48px;
  }

  .identity-row {
    grid-template-columns: 112px 1fr;
    gap: 18px;
  }

  .portrait {
    width: 112px;
    height: 112px;
    border-width: 4px;
  }

  .identity-text { padding-top: 0; }

  .identity-text h1 { font-size: clamp(2.1rem, 9vw, 3rem); }

  .email-line { font-size: 0.94rem; }

  .section-label,
  .section-head h2 { font-size: 2.35rem; }

  .section-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
  }

  .news-list li {
    grid-template-columns: 1fr;
    gap: 2px;
  }

  .pub-item {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .pub-icon { display: none; }

  .pub-main h3 { font-size: 1.45rem; }

  .page-shell { padding: 40px 0 56px; }

  .footer { flex-direction: column; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}