/* ==========================================================================
   Abhiram Nair - personal site
   Single shared stylesheet. No external dependencies, no web fonts:
   everything is served from public_html so the page works on a cold cache.
   ========================================================================== */

/* --- Design tokens ------------------------------------------------------ */
:root {
  --bg:          #ffffff;
  --surface:     #f7f8fa;
  --surface-2:   #ffffff;
  --text:        #15181c;
  --muted:       #5b626b;
  --faint:       #868e98;
  --accent:      #bf5700;          /* UT Austin burnt orange */
  --accent-text: #9c4700;
  --accent-soft: rgba(191, 87, 0, 0.09);
  --border:      #e3e6ea;
  --border-firm: #d2d7dd;
  --shadow-sm:   0 1px 2px rgba(16, 20, 26, 0.05);
  --shadow-md:   0 4px 16px rgba(16, 20, 26, 0.07);

  --maxw:   74rem;
  --readw:  40rem;
  --radius: 12px;
  --gutter: 1.5rem;

  --sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue",
          Arial, "Noto Sans", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas,
          "Liberation Mono", monospace;
}

/* Dark theme: follow the OS unless the visitor has picked a theme by hand. */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg:          #0e1013;
    --surface:     #15181d;
    --surface-2:   #181c22;
    --text:        #e8eaed;
    --muted:       #9aa2ac;
    --faint:       #79828d;
    --accent:      #ff8a3d;
    --accent-text: #ff9a56;
    --accent-soft: rgba(255, 138, 61, 0.12);
    --border:      #262b32;
    --border-firm: #343a43;
    --shadow-sm:   0 1px 2px rgba(0, 0, 0, 0.4);
    --shadow-md:   0 4px 16px rgba(0, 0, 0, 0.45);
  }
}

:root[data-theme="dark"] {
  --bg:          #0e1013;
  --surface:     #15181d;
  --surface-2:   #181c22;
  --text:        #e8eaed;
  --muted:       #9aa2ac;
  --faint:       #79828d;
  --accent:      #ff8a3d;
  --accent-text: #ff9a56;
  --accent-soft: rgba(255, 138, 61, 0.12);
  --border:      #262b32;
  --border-firm: #343a43;
  --shadow-sm:   0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md:   0 4px 16px rgba(0, 0, 0, 0.45);
}

/* --- Base --------------------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
  }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: var(--sans);
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4 {
  margin: 0 0 0.5em;
  line-height: 1.2;
  font-weight: 650;
  letter-spacing: -0.018em;
}

h1 { font-size: clamp(2.1rem, 6vw, 3.1rem); letter-spacing: -0.03em; }
h2 { font-size: clamp(1.45rem, 3.4vw, 1.8rem); }
h3 { font-size: 1.08rem; letter-spacing: -0.01em; }

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

a {
  color: var(--accent-text);
  text-decoration-color: color-mix(in srgb, var(--accent) 40%, transparent);
  text-underline-offset: 3px;
}
a:hover { text-decoration-color: var(--accent); }

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

ul { margin: 0 0 1rem; padding-left: 1.15rem; }
li { margin-bottom: 0.35rem; }
li:last-child { margin-bottom: 0; }

hr {
  border: 0;
  border-top: 1px solid var(--border);
  margin: 2.5rem 0;
}

/* --- Layout helpers ----------------------------------------------------- */
.wrap {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 100;
  background: var(--accent);
  color: #fff;
  padding: 0.6rem 1rem;
  border-radius: 0 0 var(--radius) 0;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

section { padding-block: clamp(2.75rem, 7vw, 4.5rem); }
section + section { border-top: 1px solid var(--border); }

.section-head { margin-bottom: 2rem; max-width: var(--readw); }
.section-head p { color: var(--muted); margin-bottom: 0; }

.eyebrow {
  display: block;
  font-size: 0.74rem;
  font-weight: 700;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--accent-text);
  margin-bottom: 0.65rem;
}

.lead {
  font-size: 1.12rem;
  color: var(--muted);
  max-width: var(--readw);
}

.prose { max-width: var(--readw); }
.prose p { color: var(--muted); }
.prose strong { color: var(--text); font-weight: 620; }

/* --- Header / navigation ------------------------------------------------ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: saturate(180%) blur(12px);
  -webkit-backdrop-filter: saturate(180%) blur(12px);
  border-bottom: 1px solid var(--border);
}

.site-header .wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  min-height: 4rem;
  flex-wrap: wrap;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 680;
  color: var(--text);
  text-decoration: none;
  letter-spacing: -0.015em;
}

.brand-mark {
  display: grid;
  place-items: center;
  width: 2rem;
  height: 2rem;
  flex: none;
  border-radius: 8px;
  background: var(--accent);
  color: #fff;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.nav {
  display: flex;
  align-items: center;
  gap: 0.25rem;
  flex-wrap: wrap;
}

.nav a {
  display: inline-block;
  padding: 0.4rem 0.7rem;
  border-radius: 8px;
  color: var(--muted);
  font-size: 0.93rem;
  font-weight: 540;
  text-decoration: none;
}
.nav a:hover { color: var(--text); background: var(--surface); }
.nav a[aria-current="page"] {
  color: var(--accent-text);
  background: var(--accent-soft);
  font-weight: 620;
}

.theme-toggle {
  display: grid;
  place-items: center;
  width: 2.1rem;
  height: 2.1rem;
  margin-left: 0.3rem;
  padding: 0;
  border: 1px solid var(--border-firm);
  border-radius: 8px;
  background: transparent;
  color: var(--muted);
  cursor: pointer;
  font-size: 0.95rem;
  line-height: 1;
}
.theme-toggle:hover { color: var(--text); background: var(--surface); }

/* `display: grid` above would otherwise beat the UA rule for [hidden], leaving a
   dead empty button for visitors with JavaScript disabled. */
.theme-toggle[hidden] { display: none; }

/* --- Hero --------------------------------------------------------------- */
.hero {
  padding-block: clamp(3rem, 9vw, 5.5rem);
  border-top: 0;
}

.hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 2.5rem;
  align-items: start;
}

@media (min-width: 56rem) {
  .hero-grid { grid-template-columns: minmax(0, 1fr) 15rem; gap: 3.5rem; }
}

.hero h1 { margin-bottom: 0.4rem; }

.hero-sub {
  font-size: 1.05rem;
  font-weight: 560;
  color: var(--text);
  margin-bottom: 1.1rem;
}

/* Portrait slot. Swap .portrait-fallback for <img class="portrait"> later. */
.portrait-frame {
  width: 11rem;
  height: 11rem;
  border-radius: 16px;
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
  background: var(--surface);
}

.portrait { width: 100%; height: 100%; object-fit: cover; display: block; }

.portrait-fallback {
  width: 100%;
  height: 100%;
  display: grid;
  place-items: center;
  background:
    radial-gradient(120% 120% at 25% 15%,
      color-mix(in srgb, var(--accent) 22%, transparent) 0%,
      transparent 62%),
    var(--surface);
  color: var(--accent-text);
  font-size: 2.6rem;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.facts {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.5rem;
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
}

.facts li {
  margin: 0;
  padding: 0.3rem 0.7rem;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.84rem;
  font-weight: 540;
}

/* --- Buttons ------------------------------------------------------------ */
.actions { display: flex; flex-wrap: wrap; gap: 0.65rem; margin-top: 1.5rem; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.6rem 1.1rem;
  border: 1px solid transparent;
  border-radius: 9px;
  font-size: 0.94rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.12s ease, background 0.12s ease, border-color 0.12s ease;
}
.btn:hover { transform: translateY(-1px); }

.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: color-mix(in srgb, var(--accent) 88%, #000); }

/* The generated email link must not pick up the global anchor colour. */
.btn a, .btn a:hover { color: inherit; text-decoration: none; }

/* Email slot before JavaScript upgrades it to a button. */
.email-slot:not(.btn) {
  align-self: center;
  color: var(--muted);
  font-size: 0.94rem;
}

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-firm);
}
.btn-ghost:hover { background: var(--surface); border-color: var(--accent); }

/* --- Cards -------------------------------------------------------------- */
.grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 17rem), 1fr));
}

.card {
  padding: 1.4rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-2);
  box-shadow: var(--shadow-sm);
}

.card h3 { margin-bottom: 0.4rem; }
.card p { color: var(--muted); font-size: 0.95rem; margin-bottom: 0; }

.card-num {
  display: block;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-text);
  margin-bottom: 0.7rem;
}

/* --- Entry list (experience, awards, education) ------------------------- */
.entries { display: grid; gap: 1.5rem; }

.entry {
  display: grid;
  gap: 0.2rem 2rem;
  grid-template-columns: minmax(0, 1fr);
  padding-bottom: 1.5rem;
  border-bottom: 1px solid var(--border);
}
.entry:last-child { padding-bottom: 0; border-bottom: 0; }

@media (min-width: 46rem) {
  .entry { grid-template-columns: 11rem minmax(0, 1fr); }
  .entry-when { text-align: left; padding-top: 0.15rem; }
}

.entry-when {
  color: var(--faint);
  font-size: 0.84rem;
  font-weight: 560;
  font-variant-numeric: tabular-nums;
}

.entry-body h3 { margin-bottom: 0.15rem; }

.entry-role {
  display: block;
  color: var(--accent-text);
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
}

.entry-body p, .entry-body li { color: var(--muted); font-size: 0.95rem; }

/* --- Project cards ------------------------------------------------------ */
.projects { display: grid; gap: 1.25rem; }

@media (min-width: 52rem) {
  .projects { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

.project {
  display: flex;
  flex-direction: column;
  padding: 1.6rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-2);
  box-shadow: var(--shadow-sm);
  transition: border-color 0.15s ease, box-shadow 0.15s ease;
}
.project:hover { border-color: var(--border-firm); box-shadow: var(--shadow-md); }

.project-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.1rem;
}

.project-when {
  flex: none;
  color: var(--faint);
  font-size: 0.8rem;
  font-weight: 560;
  font-variant-numeric: tabular-nums;
}

.project h3 { margin-bottom: 0; }

.project-role {
  display: block;
  color: var(--accent-text);
  font-size: 0.86rem;
  font-weight: 600;
  margin: 0.3rem 0 0.7rem;
}

.project p { color: var(--muted); font-size: 0.95rem; flex-grow: 1; }

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin: 1rem 0 0;
  padding: 0;
  list-style: none;
}

.tags li {
  margin: 0;
  padding: 0.18rem 0.55rem;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface);
  color: var(--muted);
  font-family: var(--mono);
  font-size: 0.74rem;
}

.badge {
  display: inline-block;
  margin-top: 0.9rem;
  padding: 0.22rem 0.6rem;
  border-radius: 6px;
  background: var(--accent-soft);
  color: var(--accent-text);
  font-size: 0.8rem;
  font-weight: 620;
  align-self: flex-start;
}

/* --- Callout ------------------------------------------------------------ */
.callout {
  max-width: var(--readw);
  padding: 1.1rem 1.3rem;
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--surface);
  color: var(--muted);
  font-size: 0.95rem;
}
.callout strong { color: var(--text); font-weight: 620; }
.callout :last-child { margin-bottom: 0; }

/* --- Skills ------------------------------------------------------------- */
.skills { display: grid; gap: 1.25rem; }

@media (min-width: 44rem) {
  .skills { grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr)); }
}

.skill-group h3 {
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--faint);
  margin-bottom: 0.7rem;
}

.chips { display: flex; flex-wrap: wrap; gap: 0.35rem; margin: 0; padding: 0; list-style: none; }

.chips li {
  margin: 0;
  padding: 0.25rem 0.6rem;
  border: 1px solid var(--border);
  border-radius: 7px;
  background: var(--surface);
  font-size: 0.85rem;
  color: var(--muted);
}

/* --- Footer ------------------------------------------------------------- */
.site-footer {
  border-top: 1px solid var(--border);
  background: var(--surface);
  padding-block: 2.25rem;
  color: var(--muted);
  font-size: 0.9rem;
}

.site-footer .wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem 2rem;
  align-items: center;
  justify-content: space-between;
}

.footer-links { display: flex; flex-wrap: wrap; gap: 0.25rem 1.2rem; }
.footer-links a { color: var(--muted); text-decoration: none; }
.footer-links a:hover { color: var(--accent-text); text-decoration: underline; }

.footer-note { color: var(--faint); font-size: 0.83rem; margin: 0; }