/* ============================================================
   Siva Karthik Parimi — executive editorial
   Palette: ink · warm ivory · muted gold
   Type:    Fraunces (display) · Inter (text) · Spline Sans Mono (labels)
   ============================================================ */
:root {
  --bg:        #0a0c10;
  --bg-soft:   #0d1016;
  --surface:   #12151d;
  --line:      #20242e;
  --line-soft: #1a1e27;
  --text:      #eceae4;
  --body:      #b9bcc4;
  --muted:     #82879273;
  --muted-2:   #7e8490;
  --gold:      #d4af6a;
  --gold-soft: #b89557;
  --gold-dim:  rgba(212, 175, 106, .14);
  --maxw:      1120px;
  --shadow-photo: 0 30px 80px -30px rgba(0,0,0,.8);
  --shadow-book:  0 24px 60px -24px rgba(0,0,0,.8);
  --press-name: #9aa0ab;
  --serif:     'Fraunces', Georgia, serif;
  --sans:      'Inter', system-ui, -apple-system, sans-serif;
  --mono:      'Spline Sans Mono', ui-monospace, monospace;
}

html[data-theme="light"] {
  --bg:        #f7f4ec;
  --bg-soft:   #f1ecdf;
  --surface:   #fdfbf6;
  --line:      #d9d1bd;
  --line-soft: #e6e0d0;
  --text:      #181a1f;
  --body:      #3d424b;
  --muted:     #6b7280;
  --muted-2:   #5f6671;
  --gold:      #8a6322;
  --gold-soft: #7d5a1f;
  --gold-dim:  rgba(154, 116, 52, .22);
  --shadow-photo: 0 24px 60px -28px rgba(60, 45, 15, .30);
  --shadow-book:  0 18px 44px -20px rgba(60, 45, 15, .28);
  --press-name: #565d68;
}
html[data-theme="light"] .btn--solid { background: #b8924a; color: #14100a; }
html[data-theme="light"] .hero__caption span,
html[data-theme="light"] .kicker { color: #7d5a1f; }

* { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 92px; }
body {
  transition: background .35s ease, color .35s ease;
  font-family: var(--sans);
  font-weight: 400;
  background: var(--bg);
  color: var(--body);
  line-height: 1.7;
  font-size: 1.0rem;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; height: auto; display: block; }
::selection { background: var(--gold); color: #14100a; }

.container { width: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 28px; }

.skip-link { position: absolute; left: -999px; top: 0; z-index: 100; background: var(--gold); color: #14100a; padding: 10px 16px; }
.skip-link:focus { left: 0; }

/* ---------- KICKER (mono section label) ---------- */
.kicker {
  font-family: var(--mono);
  font-size: .78rem;
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--gold);
  margin-bottom: 22px;
}

/* ---------- NAV ---------- */
.nav {
  position: fixed; inset: 0 0 auto 0; z-index: 50;
  background: color-mix(in srgb, var(--bg) 86%, transparent);
  backdrop-filter: blur(16px) saturate(1.2);
  border-bottom: 1px solid transparent;
  transition: border-color .35s;
}
.nav.is-scrolled { border-bottom-color: var(--line-soft); }
.nav__inner { display: flex; align-items: center; justify-content: space-between; gap: 40px; height: 76px; }
.nav__brand {
  display: flex; align-items: center; gap: 14px;
  white-space: nowrap; flex-shrink: 0;
  font-family: var(--serif);
  font-weight: 520;
  font-size: 1.12rem;
  letter-spacing: .01em;
  color: var(--text);
}
.nav__logo { color: var(--gold); flex-shrink: 0; }
.nav__links { display: flex; align-items: center; gap: clamp(16px, 2.2vw, 30px); }
.nav__links a {
  font-size: .88rem; font-weight: 450; color: var(--muted-2);
  letter-spacing: .02em; transition: color .2s;
}
.nav__links a:hover { color: var(--text); }
.nav__contact { color: var(--gold) !important; }
.nav__contact:hover { color: var(--text) !important; }
.nav__toggle { display: none; flex-direction: column; gap: 6px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__toggle span { width: 22px; height: 1.5px; background: var(--text); transition: .3s; }
.nav__toggle[aria-expanded="true"] span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.nav__toggle[aria-expanded="true"] span:nth-child(2) { transform: translateY(-3.5px) rotate(-45deg); }

/* ---------- THEME TOGGLE ---------- */
.theme-toggle {
  display: inline-flex; align-items: center; justify-content: center;
  width: 38px; height: 38px; border-radius: 999px;
  background: none; border: 1px solid var(--line); color: var(--muted-2);
  cursor: pointer; transition: color .2s, border-color .2s, transform .3s;
  margin-left: 20px; flex-shrink: 0;
}
.theme-toggle:hover { color: var(--gold); border-color: var(--gold); transform: rotate(15deg); }
.theme-toggle svg { width: 17px; height: 17px; }
.theme-toggle .icon-sun { display: block; }
.theme-toggle .icon-moon { display: none; }
html[data-theme="light"] .theme-toggle .icon-sun { display: none; }
html[data-theme="light"] .theme-toggle .icon-moon { display: block; }

/* ---------- BUTTONS ---------- */
.btn {
  display: inline-flex; align-items: center;
  padding: 14px 28px;
  font-size: .92rem; font-weight: 500; letter-spacing: .02em;
  border: 1px solid transparent;
  transition: background .25s, border-color .25s, color .25s;
}
.btn--solid { background: var(--gold); color: #15110a; }
.btn--solid:hover { background: var(--text); }
.btn--line { border-color: var(--line); color: var(--text); }
.btn--line:hover { border-color: var(--gold); color: var(--gold); }

/* ---------- HERO ---------- */
.hero { padding: 170px 0 0; position: relative; }
.hero::before {
  content: ""; position: absolute; top: 0; right: 8%; width: 1px; height: 100%;
  background: linear-gradient(180deg, transparent, var(--line-soft) 30%, transparent);
  pointer-events: none;
}
.hero__inner {
  display: grid; grid-template-columns: 1.18fr .82fr;
  gap: 72px; align-items: center;
}
.hero__title {
  font-family: var(--serif);
  font-weight: 520;
  font-size: clamp(2.4rem, 4.6vw, 3.7rem);
  line-height: 1.12;
  letter-spacing: -.015em;
  color: var(--text);
  margin-bottom: 28px;
}
.hero__lead {
  font-size: 1.12rem; line-height: 1.75; max-width: 33em;
  color: var(--body); margin-bottom: 38px;
}
.hero__actions { display: flex; gap: 16px; flex-wrap: wrap; margin-bottom: 56px; }
.hero__stats {
  display: grid; grid-template-columns: repeat(4, auto);
  gap: 40px; padding-top: 30px;
  border-top: 1px solid var(--line-soft);
}
.hero__stats div { display: flex; flex-direction: column; gap: 2px; }
.hero__stats dt {
  font-family: var(--serif); font-weight: 520; font-size: 1.65rem;
  color: var(--text); letter-spacing: -.01em;
}
.hero__stats dd { font-size: .8rem; color: var(--muted-2); letter-spacing: .01em; }

.hero__photo { justify-self: end; margin: 0; position: relative; }
.hero__photo picture { display: block; }
.hero__photo img {
  width: 100%; max-width: 380px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-photo);
}
.hero__photo::before {
  content: ""; position: absolute; top: 18px; left: -18px; right: 18px; bottom: -18px;
  border: 1px solid var(--gold-dim); pointer-events: none;
}
.hero__caption {
  margin-top: 18px;
  font-size: .8rem; color: var(--muted-2); letter-spacing: .02em;
}
.hero__caption span {
  color: var(--gold); font-weight: 500; margin-right: 8px;
  font-family: var(--mono); font-size: .76rem; letter-spacing: .12em; text-transform: uppercase;
}

.hero__press {
  display: flex; align-items: baseline; gap: 34px; flex-wrap: wrap;
  margin-top: 86px; padding: 26px 28px;
  border-top: 1px solid var(--line-soft);
}
.hero__press span, .hero__press a { color: var(--muted-2); font-size: .9rem; letter-spacing: .04em; }
.hero__press span:not(.hero__press-label), .hero__press a { font-family: var(--serif); font-weight: 520; color: var(--press-name); }
.hero__press a { transition: color .2s; border-bottom: 1px solid transparent; }
.hero__press a:hover { color: var(--gold); border-bottom-color: var(--gold-dim); }
.hero__press-label {
  font-family: var(--mono); font-size: .72rem !important; letter-spacing: .2em !important;
  text-transform: uppercase; color: var(--muted-2);
}

/* ---------- SECTIONS ---------- */
.section { padding: 110px 0 30px; }
.section--rule .container { border-top: 1px solid var(--line-soft); padding-top: 84px; }
.section--rule { padding-top: 30px; }
.section__head { max-width: 760px; margin-bottom: 64px; }
.section__title {
  font-family: var(--serif); font-weight: 520;
  font-size: clamp(1.7rem, 3.2vw, 2.4rem);
  line-height: 1.2; letter-spacing: -.01em; color: var(--text);
}
.section__sub { margin-top: 16px; color: var(--muted-2); font-size: 1rem; }
.section__sub a { color: var(--gold); border-bottom: 1px solid var(--gold-dim); }
.section__sub a:hover { border-bottom-color: var(--gold); }

/* ---------- FEATURE (signature work) ---------- */
.feature {
  display: grid; grid-template-columns: 1.5fr .9fr; gap: 64px;
  padding: 52px 0; border-top: 1px solid var(--line-soft);
}
.feature:last-child { border-bottom: 0; }
.feature__main h3 {
  font-family: var(--serif); font-weight: 520; font-size: 1.7rem;
  color: var(--text); letter-spacing: -.01em; margin-bottom: 6px;
}
.feature__role {
  font-family: var(--mono); font-size: .76rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--gold); margin-bottom: 22px;
}
.feature__main p + p { margin-top: 16px; }
.feature__facts {
  display: flex; flex-direction: column; gap: 26px;
  padding-left: 40px; border-left: 1px solid var(--line-soft);
  align-self: center;
}
.feature__facts strong {
  display: block; font-family: var(--serif); font-weight: 520;
  font-size: 1.55rem; color: var(--gold); letter-spacing: -.01em;
}
.feature__facts span { font-size: .84rem; color: var(--muted-2); }

/* ---------- EXPERTISE ---------- */
.expertise {
  display: grid; grid-template-columns: repeat(3, 1fr);
  gap: 0; border-top: 1px solid var(--line-soft); border-left: 1px solid var(--line-soft);
}
.expertise > div {
  padding: 34px 32px 38px;
  border-right: 1px solid var(--line-soft); border-bottom: 1px solid var(--line-soft);
}
.expertise dt {
  font-family: var(--serif); font-weight: 520; font-size: 1.14rem;
  color: var(--text); margin-bottom: 12px;
}
.expertise dd { font-size: .92rem; line-height: 1.7; color: var(--muted-2); }

/* ---------- EXPERIENCE ---------- */
.xp { list-style: none; }
.xp li {
  display: grid; grid-template-columns: 200px 1fr; gap: 40px;
  padding: 38px 0; border-top: 1px solid var(--line-soft);
}
.xp__when {
  font-family: var(--mono); font-size: .8rem; letter-spacing: .1em;
  color: var(--gold-soft); padding-top: 6px;
}
.xp__what h3 {
  font-family: var(--serif); font-weight: 520; font-size: 1.28rem;
  color: var(--text); margin-bottom: 4px;
}
.xp__org { font-size: .86rem; color: var(--muted-2); margin-bottom: 12px; letter-spacing: .02em; }
.xp__what p:last-child { font-size: .96rem; color: var(--body); max-width: 56em; }

/* ---------- PATENTS ---------- */
.patents { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; }
.patent__role {
  font-family: var(--mono); font-size: .76rem; letter-spacing: .16em;
  text-transform: uppercase; color: var(--muted-2); margin-bottom: 18px;
}
.patent__role--sole { color: var(--gold); }
.patent h3 {
  font-family: var(--serif); font-weight: 520; font-size: 1.22rem; line-height: 1.4;
  color: var(--text); margin-bottom: 16px;
}
.patent p { font-size: .95rem; color: var(--body); }
.patent__cite {
  margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line-soft);
  font-size: .82rem !important; color: var(--muted-2) !important; letter-spacing: .02em;
}

/* ---------- RESEARCH ---------- */
.rgroup {
  font-family: var(--mono); font-size: .76rem; font-weight: 500;
  letter-spacing: .18em; text-transform: uppercase; color: var(--muted-2);
  margin: 44px 0 8px;
}
.pubs { list-style: none; counter-reset: pub; }
.pubs li {
  display: grid; grid-template-columns: 1fr auto; gap: 30px; align-items: baseline;
  padding: 18px 0; border-bottom: 1px solid var(--line-soft);
}
.pubs__t { color: var(--text); font-size: .98rem; font-weight: 450; line-height: 1.55; }
.pubs__m { font-family: var(--mono); font-size: .78rem; color: var(--gold-soft); letter-spacing: .04em; white-space: nowrap; }

/* ---------- BOOK ---------- */
.book { display: grid; grid-template-columns: 240px 1fr; gap: 56px; align-items: center; }
.book__cover { position: relative; display: block; }
.book__cover img {
  width: 100%; border: 1px solid var(--line);
  box-shadow: var(--shadow-book);
  transition: transform .3s;
}
.book__cover:hover img { transform: translateY(-4px); }
.book__cover::before {
  content: ""; position: absolute; top: 14px; left: -14px; right: 14px; bottom: -14px;
  border: 1px solid rgba(212, 175, 106, .25); pointer-events: none;
}
.book__body h3 {
  font-family: var(--serif); font-weight: 520; font-size: 1.6rem; line-height: 1.25;
  color: var(--text); margin-bottom: 6px; letter-spacing: -.01em;
}
.book__sub {
  font-family: var(--serif); font-size: 1.05rem; color: var(--muted-2);
  font-style: italic; margin-bottom: 18px;
}
.book__body > p:not(.book__sub):not(.feature__role) { max-width: 54em; }
.book__actions { margin-top: 26px; }

/* ---------- SPEAKING ---------- */
.cols { display: grid; grid-template-columns: 1fr 1fr; gap: 64px; }
.rlist { list-style: none; }
.rlist li { padding: 14px 0; border-bottom: 1px solid var(--line-soft); font-size: .95rem; color: var(--muted-2); line-height: 1.6; }
.rlist strong { color: var(--text); font-weight: 500; }
.note {
  margin-top: 48px; padding: 24px 30px;
  border-left: 2px solid var(--gold); background: var(--bg-soft);
  font-size: .95rem; color: var(--body);
}

/* ---------- RECOGNITION ---------- */
.honors { display: grid; grid-template-columns: repeat(3, 1fr); gap: 56px; }
.honor h3 {
  font-family: var(--serif); font-weight: 520; font-size: 1.16rem; line-height: 1.4;
  color: var(--text); margin-bottom: 12px;
}
.honor p { font-size: .92rem; color: var(--muted-2); }
.honor__link {
  display: inline-block; margin-top: 14px;
  font-family: var(--mono); font-size: .78rem; letter-spacing: .04em;
  color: var(--gold-soft); transition: color .2s;
}
.honor__link:hover { color: var(--gold); }
.honor__link:hover .press__arrow { opacity: 1; transform: translate(2px, -2px); }

/* ---------- PRESS ---------- */
.press { display: grid; }
.press__row {
  display: grid; grid-template-columns: 1fr auto; gap: 30px; align-items: baseline;
  padding: 18px 0; border-bottom: 1px solid var(--line-soft);
  transition: padding-left .25s;
}
a.press__row:hover { padding-left: 10px; }
a.press__row:hover .press__t { color: var(--gold); }
a.press__row:hover .press__arrow { opacity: 1; transform: translate(2px, -2px); }
.press__t { color: var(--text); font-size: .98rem; font-weight: 450; line-height: 1.55; transition: color .2s; }
.press__m { font-family: var(--mono); font-size: .78rem; color: var(--gold-soft); letter-spacing: .04em; white-space: nowrap; }
.press__arrow { display: inline-block; opacity: .35; transition: opacity .2s, transform .2s; margin-left: 4px; }
.press__row--static .press__t { color: var(--body); }

/* ---------- CONTACT ---------- */
.section--contact { padding-bottom: 130px; }
.contact__title {
  font-family: var(--serif); font-weight: 520;
  font-size: clamp(1.5rem, 2.9vw, 2.15rem);
  line-height: 1.35; letter-spacing: -.01em; color: var(--text);
  max-width: 26em; margin-bottom: 44px;
}
.contact__row { display: flex; gap: 16px; flex-wrap: wrap; }

/* ---------- FOOTER ---------- */
.footer { border-top: 1px solid var(--line-soft); padding: 30px 0; }
.footer__inner {
  display: flex; justify-content: space-between;
  font-size: .82rem; color: var(--muted-2); letter-spacing: .03em;
}

/* ---------- REVEAL ---------- */
.reveal { opacity: 0; transform: translateY(18px); transition: opacity .8s cubic-bezier(.2,.6,.2,1), transform .8s cubic-bezier(.2,.6,.2,1); }
.reveal.is-visible { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  .reveal { opacity: 1; transform: none; transition: none; }
  html { scroll-behavior: auto; }
}

/* ---------- RESPONSIVE ---------- */
@media (max-width: 980px) {
  .hero__inner { grid-template-columns: 1fr; gap: 56px; }
  .hero__photo { justify-self: start; }
  .feature { grid-template-columns: 1fr; gap: 34px; }
  .feature__facts { flex-direction: row; gap: 40px; padding-left: 0; border-left: 0; padding-top: 26px; border-top: 1px solid var(--line-soft); }
  .expertise { grid-template-columns: 1fr 1fr; }
  .patents { grid-template-columns: 1fr; gap: 48px; }
  .book { grid-template-columns: 1fr; gap: 40px; }
  .book__cover { max-width: 240px; }
  .honors { grid-template-columns: 1fr; gap: 36px; }
  .cols { grid-template-columns: 1fr; gap: 40px; }
}
@media (max-width: 680px) {
  .nav__links {
    position: fixed; top: 76px; left: 0; right: 0; flex-direction: column; align-items: stretch; gap: 0;
    background: var(--bg-soft); border-bottom: 1px solid var(--line);
    padding: 10px 0; transform: translateY(-130%); transition: transform .35s;
  }
  .nav__links.is-open { transform: translateY(0); }
  .nav__links a { padding: 15px 28px; }
  .nav__toggle { display: flex; }
  .theme-toggle { margin-left: auto; margin-right: 14px; }
  .hero { padding-top: 130px; }
  .hero__stats { grid-template-columns: 1fr 1fr; gap: 26px; }
  .hero__photo img { max-width: 100%; }
  .hero__photo::before { display: none; }
  .hero__press { gap: 18px; margin-top: 60px; }
  .expertise { grid-template-columns: 1fr; }
  .xp li { grid-template-columns: 1fr; gap: 8px; padding: 30px 0; }
  .feature__facts { flex-direction: column; gap: 22px; }
  .pubs li { grid-template-columns: 1fr; gap: 4px; }
  .pubs__m { white-space: normal; }
  .press__row { grid-template-columns: 1fr; gap: 4px; }
  .press__m { white-space: normal; }
  .section { padding: 80px 0 20px; }
  .section--rule .container { padding-top: 64px; }
  .footer__inner { flex-direction: column; gap: 6px; }
}