/* ============================================================
   adithya rajesh pillai — personal site
   ============================================================ */

:root {
  --bg:        #FAF0E6;
  --cream:     #F1D5BA;
  --tan:       #E8BB8D;
  --orange:    #DFA061;
  --brown:     #593512;
  --green:     #84B067;
  --brown-50:  rgba(89, 53, 18, 0.5);
  --brown-15:  rgba(89, 53, 18, 0.15);
  --brown-08:  rgba(89, 53, 18, 0.08);

  --font-display: "Newsreader", Georgia, serif;
  --font-body:    "Manrope", "Helvetica Neue", sans-serif;
}

/* ============================================================
   DARK MODE
   ============================================================ */

[data-theme="dark"] {
  --bg:        #13100c;
  --cream:     #1f1710;
  --tan:       #2d2015;
  --orange:    #DFA061;
  --brown:     #e9c99a;
  --green:     #84B067;
  --brown-50:  rgba(233, 201, 154, 0.5);
  --brown-15:  rgba(233, 201, 154, 0.15);
  --brown-08:  rgba(233, 201, 154, 0.08);
}

[data-theme="dark"] body::before {
  opacity: 0.06;
  mix-blend-mode: screen;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--brown);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

/* subtle paper texture — no dot grid */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  opacity: 0.22;
  mix-blend-mode: multiply;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='200' height='200'><filter id='n'><feTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='2' stitchTiles='stitch'/><feColorMatrix values='0 0 0 0 0.35  0 0 0 0 0.21  0 0 0 0 0.07  0 0 0 0.18 0'/></filter><rect width='100%' height='100%' filter='url(%23n)'/></svg>");
}

a { color: inherit; text-decoration: none; }

/* ============================================================
   HEADER / NAV
   ============================================================ */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg);
  border-bottom: 1px solid var(--brown-15);
}

.header-inner {
  position: relative;
  max-width: 720px;
  margin: 0 auto;
  padding: 1.1rem 2rem;
  display: flex;
  justify-content: center;
  align-items: center;
}

.theme-toggle {
  position: absolute;
  right: 2rem;
  top: 50%;
  transform: translateY(-50%);
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.3rem;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--brown);
  opacity: 0.45;
  transition: opacity 0.2s;
  border-radius: 4px;
  line-height: 0;
}

.theme-toggle:hover { opacity: 1; }

.theme-toggle svg {
  width: 17px;
  height: 17px;
}

.brand {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  color: var(--brown);
  opacity: 0.85;
  transition: opacity 0.2s;
}

.brand:hover { opacity: 1; }

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  align-items: center;
}

.nav-list a {
  font-family: var(--font-body);
  font-size: 0.875rem;
  color: var(--brown);
  opacity: 0.55;
  white-space: nowrap;
  transition: opacity 0.2s;
}

.nav-list a:hover { opacity: 0.9; }

.nav-list a.is-current {
  opacity: 1;
  text-decoration: underline;
  text-underline-offset: 4px;
  text-decoration-thickness: 1px;
}

/* ============================================================
   MAIN CONTENT
   ============================================================ */

.content-col {
  position: relative;
  z-index: 1;
  max-width: 680px;
  margin: 0 auto;
  padding: 4.5rem 2rem 6rem;
}

.section { display: none; }

.section.is-active {
  display: block;
  animation: fade-up 0.28s ease;
}

@keyframes fade-up {
  from { opacity: 0; transform: translateY(6px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   HOME / HERO
   ============================================================ */

.hero-photo-wrap {
  width: 120px;
  height: 120px;
  border-radius: 50%;
  overflow: hidden;
  background: radial-gradient(circle at 30% 30%, var(--tan), var(--orange) 70%);
  display: grid;
  place-items: center;
  margin: 0 auto 2.2rem;
}

.hero-photo-wrap img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-photo-placeholder {
  font-family: var(--font-display);
  font-size: 3rem;
  font-weight: 400;
  color: var(--brown);
  user-select: none;
}

.name {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.02em;
  font-size: clamp(2.2rem, 5vw, 3.2rem);
  line-height: 1.1;
  margin: 0 0 0.55rem;
  color: var(--brown);
  text-align: center;
}

.role {
  font-size: 1rem;
  color: var(--brown);
  opacity: 0.6;
  margin: 0 0 1.4rem;
  text-align: center;
}

.bio {
  max-width: 46ch;
  font-size: 0.975rem;
  line-height: 1.72;
  color: var(--brown);
  opacity: 0.82;
  margin: 0 auto 2rem;
  text-align: center;
}

.research-bio {
  max-width: 50ch;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--brown);
  opacity: 0.6;
  margin: 1.8rem auto 0;
  text-align: center;
  border-top: 1px solid var(--brown-15);
  padding-top: 1.6rem;
}

/* ============================================================
   SOCIAL ICONS
   ============================================================ */

.socials {
  display: flex;
  gap: 1.5rem;
  align-items: flex-start;
  justify-content: center;
}

.social-link {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.4rem;
  color: var(--brown);
  opacity: 0.5;
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.social-link:hover {
  opacity: 1;
  transform: translateY(-2px);
}

.social-link svg {
  height: 28px;
  width: auto;
  max-width: 44px;
}

.social-label {
  font-family: var(--font-body);
  font-size: 0.7rem;
  letter-spacing: 0.04em;
  color: var(--brown);
}

.hero-email {
  display: block;
  margin-top: 1.6rem;
  font-size: 0.875rem;
  color: var(--brown);
  opacity: 0.6;
  text-align: center;
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--orange);
  text-decoration-thickness: 1px;
  transition: opacity 0.2s;
}

.hero-email:hover { opacity: 1; }

/* ============================================================
   SECTION TITLES
   ============================================================ */

.page-title {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.02em;
  font-size: clamp(2rem, 4.5vw, 2.8rem);
  line-height: 1.1;
  margin: 0 0 0.45rem;
  color: var(--brown);
}

.page-intro {
  font-size: 0.92rem;
  line-height: 1.68;
  color: var(--brown);
  opacity: 0.6;
  margin-bottom: 2.2rem;
  max-width: 54ch;
}

.section-subhead {
  font-family: var(--font-body);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  opacity: 0.45;
  margin: 2.5rem 0 0;
  font-weight: 600;
}

/* ============================================================
   ENTRIES
   ============================================================ */

.entry {
  padding: 1.35rem 0;
  border-top: 1px solid var(--brown-15);
}

.entry:last-child {
  border-bottom: 1px solid var(--brown-15);
}

.entry-date {
  font-size: 0.78rem;
  letter-spacing: 0.05em;
  color: var(--brown);
  opacity: 0.45;
  margin-bottom: 0.25rem;
}

.entry-title {
  font-family: var(--font-display);
  font-weight: 400;
  letter-spacing: -0.01em;
  font-size: 1.08rem;
  line-height: 1.3;
  margin: 0 0 0.2rem;
  color: var(--brown);
}

.entry-org {
  font-size: 0.86rem;
  margin: 0 0 0.6rem;
  color: var(--brown);
  opacity: 0.6;
}

.entry-org .pill {
  display: inline-block;
  font-size: 0.7rem;
  letter-spacing: 0.06em;
  padding: 0.1rem 0.45rem;
  border-radius: 999px;
  background: var(--cream);
  margin-left: 0.35rem;
  vertical-align: middle;
  text-decoration: none;
}

a.pill:hover {
  text-decoration: underline;
}

.entry-body {
  font-size: 0.91rem;
  line-height: 1.68;
  color: var(--brown);
  opacity: 0.82;
}

.entry-body p { margin: 0 0 0.4rem; }

.entry-body ul {
  padding-left: 1.1rem;
  margin: 0.4rem 0 0;
}

.entry-body li { margin-bottom: 0.3rem; }

.entry-body li::marker { color: var(--orange); }

.tag-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  margin-top: 0.75rem;
}

.tag {
  font-size: 0.72rem;
  letter-spacing: 0.04em;
  padding: 0.18rem 0.55rem;
  background: transparent;
  border: 1px solid var(--brown-15);
  border-radius: 999px;
  color: var(--brown);
  opacity: 0.7;
}

.tag.tag-accent {
  background: var(--cream);
  border-color: transparent;
  opacity: 0.85;
}

/* ============================================================
   INLINE LINKS
   ============================================================ */

.inline-link {
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--orange);
  text-decoration-thickness: 1px;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */

@media (max-width: 600px) {
  .header-inner {
    padding: 0.85rem 1.25rem;
    padding-right: 3rem;
    gap: 0.75rem;
    flex-wrap: wrap;
  }

  .theme-toggle {
    right: 1.25rem;
  }

  .nav-list {
    gap: 0.9rem;
    flex-wrap: wrap;
  }

  .nav-list a { font-size: 0.8rem; }

  .content-col {
    padding: 2.5rem 1.25rem 4rem;
  }
}