/* =============================================================
   Raj Jayaraman — Speaker Portfolio
   Confident-minimal, enterprise-credible. Dark-first with light theme.
   Accent: refined teal/cyan-green. Tinted neutrals throughout.
   ============================================================= */

/* -------------------------------------------------------------
   1. Design tokens (theme-agnostic) + color palettes
   ------------------------------------------------------------- */
:root {
  /* Fonts */
  --font-display: "Sora", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;

  /* Fluid type scale */
  --fs-eyebrow: clamp(0.72rem, 0.68rem + 0.2vw, 0.8rem);
  --fs-small: clamp(0.82rem, 0.78rem + 0.2vw, 0.9rem);
  --fs-body: clamp(1rem, 0.96rem + 0.25vw, 1.075rem);
  --fs-lead: clamp(1.1rem, 1rem + 0.7vw, 1.3rem);
  --fs-h3: clamp(1.2rem, 1.05rem + 0.7vw, 1.45rem);
  --fs-h2: clamp(1.9rem, 1.4rem + 2.2vw, 3rem);
  --fs-stat: clamp(2.6rem, 1.9rem + 3.2vw, 4rem);
  --fs-hero: clamp(2.4rem, 1.3rem + 5.2vw, 4.6rem);

  /* Fluid spacing tokens */
  --space-2xs: clamp(0.35rem, 0.3rem + 0.2vw, 0.5rem);
  --space-xs: clamp(0.6rem, 0.5rem + 0.4vw, 0.85rem);
  --space-sm: clamp(0.9rem, 0.75rem + 0.6vw, 1.25rem);
  --space-md: clamp(1.4rem, 1.1rem + 1.2vw, 2rem);
  --space-lg: clamp(2.2rem, 1.6rem + 2.4vw, 3.4rem);
  --space-xl: clamp(3.4rem, 2.4rem + 4vw, 5.6rem);
  --space-2xl: clamp(4.6rem, 3.2rem + 6vw, 8rem);

  /* Layout */
  --container: 1200px;
  --container-narrow: 760px;
  --nav-h: 4.5rem;
  --radius-sm: 10px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-pill: 999px;

  /* Motion */
  --ease-out: cubic-bezier(0.22, 0.61, 0.36, 1);
  --t-fast: 160ms;
  --t-mid: 240ms;
  --reveal-dur: 560ms;
}

/* ----- Dark theme (default) ----- */
[data-theme="dark"] {
  --bg: #0c1015;
  --surface-1: #11161d;
  --surface-2: #161d26;
  --surface-3: #1c2530;
  --border: #25303d;
  --border-strong: #344150;

  --text: #e9eef4;
  --text-muted: #aab6c4;
  --text-faint: #76828f;

  --accent: #2fd4b4;
  --accent-strong: #19b89a;
  --accent-soft: rgba(47, 212, 180, 0.14);
  --accent-contrast: #04201a;

  --nav-bg: rgba(12, 16, 21, 0.62);
  --nav-bg-scrolled: rgba(12, 16, 21, 0.88);

  --glow-1: rgba(47, 212, 180, 0.22);
  --glow-2: rgba(46, 134, 222, 0.12);

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4),
               0 2px 8px rgba(3, 7, 12, 0.5);
  --shadow-md: 0 10px 30px -12px rgba(0, 0, 0, 0.65),
               0 4px 12px -6px rgba(3, 7, 12, 0.5);
  --shadow-lg: 0 30px 60px -24px rgba(0, 0, 0, 0.75),
               0 10px 24px -12px rgba(3, 7, 12, 0.6);
  --shadow-accent: 0 18px 44px -18px rgba(47, 212, 180, 0.5);

  color-scheme: dark;
}

/* ----- Light theme ----- */
[data-theme="light"] {
  --bg: #f4f6f9;
  --surface-1: #ffffff;
  --surface-2: #eef1f5;
  --surface-3: #e6eaf0;
  --border: #dce1e8;
  --border-strong: #c4ccd6;

  --text: #16202c;
  --text-muted: #4d5a68;
  --text-faint: #7b8794;

  --accent: #0d9b82;
  --accent-strong: #0a8270;
  --accent-soft: rgba(13, 155, 130, 0.12);
  --accent-contrast: #ffffff;

  --nav-bg: rgba(244, 246, 249, 0.7);
  --nav-bg-scrolled: rgba(255, 255, 255, 0.9);

  --glow-1: rgba(13, 155, 130, 0.16);
  --glow-2: rgba(46, 134, 222, 0.1);

  --shadow-sm: 0 1px 2px rgba(22, 32, 44, 0.06),
               0 2px 8px rgba(22, 32, 44, 0.06);
  --shadow-md: 0 12px 30px -14px rgba(22, 32, 44, 0.18),
               0 4px 12px -6px rgba(22, 32, 44, 0.1);
  --shadow-lg: 0 30px 60px -26px rgba(22, 32, 44, 0.24),
               0 10px 24px -12px rgba(22, 32, 44, 0.14);
  --shadow-accent: 0 18px 44px -20px rgba(13, 155, 130, 0.4);

  color-scheme: light;
}

/* -------------------------------------------------------------
   2. Reset & base
   ------------------------------------------------------------- */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-h) + 1rem);
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.65;
  font-weight: 400;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
  transition: background-color var(--t-mid) var(--ease-out),
              color var(--t-mid) var(--ease-out);
}

h1, h2, h3 {
  font-family: var(--font-display);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--text);
}

img {
  display: block;
  max-width: 100%;
  height: auto;
}

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

ul {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
}

/* Selection */
::selection {
  background: var(--accent);
  color: var(--accent-contrast);
}

/* -------------------------------------------------------------
   3. Custom scrollbar
   ------------------------------------------------------------- */
html {
  scrollbar-width: thin;
  scrollbar-color: var(--border-strong) transparent;
}

::-webkit-scrollbar {
  width: 11px;
  height: 11px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border-strong);
  border-radius: var(--radius-pill);
  border: 3px solid var(--bg);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent);
}

/* -------------------------------------------------------------
   4. Focus + skip link
   ------------------------------------------------------------- */
:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
  border-radius: 4px;
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  transform: translateY(-120%);
  z-index: 1000;
  margin: 0.6rem;
  padding: 0.7rem 1.1rem;
  background: var(--accent);
  color: var(--accent-contrast);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-small);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-md);
  transition: transform var(--t-mid) var(--ease-out);
}

.skip-link:focus {
  transform: translateY(0);
  outline: 2px solid var(--text);
  outline-offset: 2px;
}

/* -------------------------------------------------------------
   5. Reveal animation contract
   ------------------------------------------------------------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity var(--reveal-dur) var(--ease-out),
              transform var(--reveal-dur) var(--ease-out);
  will-change: opacity, transform;
}

[data-reveal].is-revealed {
  opacity: 1;
  transform: translateY(0);
}

[data-reveal][data-reveal-delay="1"] { transition-delay: 90ms; }
[data-reveal][data-reveal-delay="2"] { transition-delay: 180ms; }
[data-reveal][data-reveal-delay="3"] { transition-delay: 270ms; }

/* -------------------------------------------------------------
   6. Layout helpers
   ------------------------------------------------------------- */
.hero__inner,
.stats__grid,
.section,
.contact__inner,
.logostrip {
  width: 100%;
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 0.6rem + 3vw, 2.5rem);
}

.section {
  max-width: var(--container);
  padding-top: var(--space-2xl);
  padding-bottom: var(--space-2xl);
}

/* Alternating section background (subtle) */
.section--alt {
  max-width: none;
  background: var(--surface-1);
  border-block: 1px solid var(--border);
}

.section--alt > * {
  max-width: var(--container);
  margin-inline: auto;
}

/* -------------------------------------------------------------
   7. Buttons
   ------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-small);
  line-height: 1;
  letter-spacing: 0.01em;
  padding: 0.85em 1.5em;
  border: 1px solid transparent;
  border-radius: var(--radius-pill);
  cursor: pointer;
  white-space: nowrap;
  transition: transform var(--t-fast) var(--ease-out),
              box-shadow var(--t-fast) var(--ease-out),
              background-color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out);
}

.btn--primary {
  background: var(--accent);
  color: var(--accent-contrast);
  box-shadow: var(--shadow-accent);
}

.btn--primary:hover {
  background: var(--accent-strong);
  transform: translateY(-2px);
  box-shadow: 0 22px 50px -18px rgba(47, 212, 180, 0.6);
}

.btn--ghost {
  background: transparent;
  color: var(--text);
  border-color: var(--border-strong);
}

.btn--ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-2px);
  background: var(--accent-soft);
}

.btn--lg {
  font-size: var(--fs-body);
  padding: 1.05em 2em;
}

.btn:active {
  transform: translateY(0);
}

/* -------------------------------------------------------------
   8. Navigation
   ------------------------------------------------------------- */
.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 900;
  background: var(--nav-bg);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid transparent;
  transition: background-color var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.nav.is-scrolled {
  background: var(--nav-bg-scrolled);
  border-bottom-color: var(--border);
  box-shadow: var(--shadow-sm);
}

.nav__inner {
  max-width: var(--container);
  margin-inline: auto;
  height: var(--nav-h);
  padding-inline: clamp(1.1rem, 0.6rem + 3vw, 2.5rem);
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.nav.is-scrolled .nav__inner {
  height: calc(var(--nav-h) - 0.6rem);
}

.nav__brand {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-eyebrow);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  white-space: nowrap;
  flex-shrink: 0;
  transition: color var(--t-fast) var(--ease-out);
}

.nav__brand:hover {
  color: var(--accent-strong);
}

.nav__links {
  display: flex;
  align-items: center;
  gap: clamp(1rem, 0.4rem + 1.6vw, 2rem);
  margin-left: auto;
}

.nav__link {
  position: relative;
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--text-muted);
  padding: 0.4rem 0;
  transition: color var(--t-fast) var(--ease-out);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 2px;
  border-radius: 2px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--t-mid) var(--ease-out);
}

.nav__link:hover {
  color: var(--text);
}

.nav__link:hover::after {
  transform: scaleX(1);
}

.nav__link.is-active {
  color: var(--accent);
}

.nav__link.is-active::after {
  transform: scaleX(1);
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

/* Theme toggle */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: var(--radius-pill);
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);
  font-size: 0.95rem;
  transition: color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out),
              background-color var(--t-fast) var(--ease-out),
              transform var(--t-fast) var(--ease-out);
}

.theme-toggle:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: translateY(-1px);
}

/* Icon visibility driven by html[data-theme] */
[data-theme="dark"] [data-theme-icon-light] { display: none; }
[data-theme="dark"] [data-theme-icon-dark]  { display: inline-block; }
[data-theme="light"] [data-theme-icon-dark]  { display: none; }
[data-theme="light"] [data-theme-icon-light] { display: inline-block; }

/* -------------------------------------------------------------
   9. Hero
   ------------------------------------------------------------- */
.hero {
  position: relative;
  overflow: hidden;
  padding-top: calc(var(--nav-h) + var(--space-xl));
  padding-bottom: var(--space-xl);
  border-bottom: 1px solid var(--border);
}

.hero__bg {
  position: absolute;
  inset: -20% -10% auto -10%;
  height: 120%;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(60% 55% at 72% 18%, var(--glow-1) 0%, transparent 60%),
    radial-gradient(50% 50% at 18% 8%, var(--glow-2) 0%, transparent 55%);
  filter: blur(8px);
}

.hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--container);
  margin-inline: auto;
  padding-inline: clamp(1.1rem, 0.6rem + 3vw, 2.5rem);
  display: grid;
  grid-template-columns: 1fr;
  align-items: center;
  gap: var(--space-lg);
}

.hero__eyebrow,
.section__eyebrow {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: var(--space-sm);
}

.hero__title {
  font-size: var(--fs-hero);
  font-weight: 800;
  margin-bottom: var(--space-2xs);
}

.hero__content {
  text-align: center;
}

.hero__subtitle {
  font-family: var(--font-display);
  font-size: var(--fs-lead);
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: var(--space-2xs);
}

.hero__degree {
  font-size: var(--fs-small);
  color: var(--text-faint);
  margin-bottom: var(--space-md);
}

/* Hero metrics row — separate square cards */
.hero__metrics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
}

.metric {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-2xs);
  padding: var(--space-md) var(--space-sm);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-md);
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.metric:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow-accent);
}

.metric__num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.8rem, 1.4rem + 1.5vw, 2.4rem);
  line-height: 1;
  color: var(--accent);
  letter-spacing: -0.03em;
}

.metric__label {
  font-size: var(--fs-eyebrow);
  font-weight: 500;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-muted);
  text-align: center;
}

/* Hero profile badges (LinkedIn, ORCID, GitHub, etc.) */
.hero__tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xs);
  margin-bottom: var(--space-lg);
}

.expertise-tag {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.02em;
  color: var(--accent);
  padding: 0.45em 0.9em;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: var(--radius-pill);
  white-space: nowrap;
  transition: transform var(--t-fast) var(--ease-out),
              box-shadow var(--t-fast) var(--ease-out),
              background-color var(--t-fast) var(--ease-out);
  cursor: default;
}

.expertise-tag:hover {
  transform: translateY(-2px);
  box-shadow: 0 0 12px var(--accent), 0 0 24px var(--glow-1), 0 0 40px var(--glow-1);
  background: rgba(47, 212, 180, 0.22);
}

.hero__profiles {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xs);
  margin-top: var(--space-md);
}

.profile-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.6em 1.1em;
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 600;
  color: var(--text);
  background: var(--surface-2);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-pill);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out),
              box-shadow var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out),
              background-color var(--t-fast) var(--ease-out);
}

.profile-badge i {
  font-size: 1.1em;
  color: var(--accent);
}

.profile-badge:hover {
  transform: translateY(-2px);
  border-color: var(--accent);
  box-shadow: var(--shadow-accent);
  color: var(--accent);
  background: var(--accent-soft);
}

.profile-badge--orcid i {
  color: #a6ce39;
}

.profile-badge--orcid:hover {
  border-color: #a6ce39;
  color: #a6ce39;
  box-shadow: 0 12px 30px -12px rgba(166, 206, 57, 0.4);
}

/* Hero banner */
.hero-banner {
  position: relative;
  z-index: 1;
  max-width: var(--container);
  margin: var(--space-lg) auto 0;
  padding-inline: clamp(1.1rem, 0.6rem + 3vw, 2.5rem);
  text-align: center;
}

.hero-banner__text {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 0.6em 1.4em;
  background: var(--accent-soft);
  border: 1px solid var(--accent);
  border-radius: var(--radius-pill);
}

/* Hero media */
.hero__media {
  position: relative;
  justify-self: center;
  width: 100%;
  max-width: 360px;
}

.hero__photo {
  position: relative;
  border-radius: var(--radius-lg);
  padding: 6px;
  background: linear-gradient(150deg, var(--accent-soft), var(--surface-1));
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
}

.hero__photo img {
  width: 100%;
  height: auto;
  aspect-ratio: 5 / 6;
  object-fit: cover;
  border-radius: calc(var(--radius-lg) - 5px);
}

.hero__cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-xs);
  margin-top: var(--space-sm);
}

/* -------------------------------------------------------------
   10. Logo strip
   ------------------------------------------------------------- */
.logostrip {
  position: relative;
  z-index: 1;
  max-width: var(--container);
  margin-top: var(--space-xl);
  padding-top: var(--space-md);
  border-top: 1px solid var(--border);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-sm) var(--space-md);
}

.logostrip__label {
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.logostrip__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: clamp(0.9rem, 0.4rem + 2vw, 2.2rem);
}

.logostrip__list li {
  position: relative;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-small);
  color: var(--text-faint);
  letter-spacing: 0.01em;
  transition: color var(--t-fast) var(--ease-out);
}

.logostrip__list li:hover {
  color: var(--text-muted);
}

.logostrip__list li:not(:last-child)::after {
  content: "";
  position: absolute;
  right: clamp(-1.1rem, -0.5rem - 1vw, -0.45rem);
  top: 50%;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--border-strong);
  transform: translateY(-50%);
}

/* -------------------------------------------------------------
   11. Stats
   ------------------------------------------------------------- */
.stats {
  padding-block: var(--space-xl);
}

.stats__grid {
  max-width: var(--container);
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-md);
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2xs);
  padding: var(--space-md);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out);
}

.stat:hover {
  transform: translateY(-3px);
  border-color: var(--border-strong);
}

.stat__num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-stat);
  line-height: 1;
  color: var(--text);
  letter-spacing: -0.03em;
}

.stat__num--mark {
  color: var(--accent);
}

.stat__label {
  font-size: var(--fs-small);
  color: var(--text-muted);
  font-weight: 500;
}

/* -------------------------------------------------------------
   12. Section heads
   ------------------------------------------------------------- */
.section__head {
  max-width: 60ch;
  margin-bottom: var(--space-lg);
}

.section__title {
  font-size: var(--fs-h2);
  margin-bottom: var(--space-sm);
}

.section__intro {
  font-size: var(--fs-lead);
  color: var(--text-muted);
  max-width: 56ch;
}

/* -------------------------------------------------------------
   13. Talks / topics
   ------------------------------------------------------------- */
.topics {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: var(--space-md);
}

.topic {
  padding: var(--space-md);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.topic:hover {
  transform: translateY(-5px);
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
}

.topic__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  margin-bottom: var(--space-sm);
  border-radius: var(--radius-md);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 1.25rem;
}

.topic__title {
  font-size: var(--fs-h3);
  margin-bottom: var(--space-xs);
}

.topic__desc {
  font-size: var(--fs-small);
  color: var(--text-muted);
}

/* -------------------------------------------------------------
   14. Events / speaking
   ------------------------------------------------------------- */
.events {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.event {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: stretch;
  text-align: left;
  padding: 0;
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  color: var(--text);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.event:hover {
  transform: translateY(-5px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

/* Photo area (top of every card) */
.event__photo {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
}

.event__photo img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  position: relative;
  z-index: 1;
  transition: transform 500ms var(--ease-out);
}

.event:hover .event__photo img {
  transform: scale(1.05);
}

/* Upload placeholder, shown behind the img. When img loads it covers this;
   when img is missing (onerror hides it) this shows through. */
.event__ph {
  position: absolute;
  inset: 0;
  z-index: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  color: var(--text-faint);
  background:
    repeating-linear-gradient(45deg, transparent, transparent 11px,
      rgba(255,255,255,0.018) 11px, rgba(255,255,255,0.018) 22px),
    var(--surface-2);
}

.event__ph i {
  font-size: 1.5rem;
  color: var(--text-faint);
}

.event__ph-name {
  font-family: var(--font-display);
  font-size: 0.68rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  color: var(--text-faint);
  background: var(--surface-1);
  border: 1px solid var(--border);
  padding: 0.25em 0.6em;
  border-radius: var(--radius-pill);
}

/* Card body (below photo) */
.event__body {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-2xs);
  padding: var(--space-md);
}

.event__badge {
  display: inline-block;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
  padding: 0.3em 0.7em;
  border: 1px solid var(--accent-soft);
  background: var(--accent-soft);
  border-radius: var(--radius-pill);
  margin-bottom: var(--space-2xs);
}

.event__year {
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.event__name {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  font-weight: 600;
  line-height: 1.2;
  color: var(--text);
}

.event__loc {
  font-size: var(--fs-small);
  color: var(--text-muted);
}

/* -------------------------------------------------------------
   15. About
   ------------------------------------------------------------- */
.about {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.about__media {
  position: relative;
  border-radius: var(--radius-lg);
  padding: 8px;
  background: linear-gradient(150deg, var(--surface-3), var(--surface-1));
  border: 1px solid var(--border);
  box-shadow: var(--shadow-lg);
  max-width: 420px;
  justify-self: center;
}

.about__media img {
  width: 100%;
  aspect-ratio: 420 / 480;
  object-fit: cover;
  border-radius: calc(var(--radius-lg) - 7px);
}

.about__body p {
  color: var(--text-muted);
  margin-bottom: var(--space-sm);
  max-width: 60ch;
}

.about__body .section__title {
  margin-top: var(--space-2xs);
}

.about__creds {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.about__creds li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  font-size: var(--fs-small);
  color: var(--text);
  font-weight: 500;
}

.about__creds li i {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2rem;
  height: 2rem;
  border-radius: var(--radius-sm);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 0.85rem;
}

/* -------------------------------------------------------------
   16. Writing / posts
   ------------------------------------------------------------- */
.writing {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-md);
}

.post {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  padding: var(--space-md);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.post:hover {
  transform: translateY(-4px);
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
}

.post__tag {
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.post__title {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  font-weight: 600;
  line-height: 1.25;
  color: var(--text);
}

.post__desc {
  font-size: var(--fs-small);
  color: var(--text-muted);
  flex-grow: 1;
}

.post__link {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-small);
  color: var(--accent);
  margin-top: var(--space-2xs);
}

.post__link i {
  transition: transform var(--t-fast) var(--ease-out);
}

.post:hover .post__link i {
  transform: translateX(5px);
}

.writing__more {
  margin-top: var(--space-md);
  font-size: var(--fs-body);
}

.writing__more a {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-family: var(--font-display);
  font-weight: 600;
  color: var(--accent);
  border-bottom: 1px solid transparent;
  transition: border-color var(--t-fast) var(--ease-out);
}

.writing__more a i {
  transition: transform var(--t-fast) var(--ease-out);
}

.writing__more a:hover {
  border-bottom-color: var(--accent);
}

.writing__more a:hover i {
  transform: translateX(5px);
}

/* -------------------------------------------------------------
   17. Contact
   ------------------------------------------------------------- */
.contact {
  text-align: center;
}

.contact__inner {
  max-width: var(--container-narrow);
  display: flex;
  flex-direction: column;
  align-items: center;
}

.contact__inner .section__eyebrow {
  margin-bottom: var(--space-sm);
}

.contact__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-h2);
  letter-spacing: -0.02em;
  margin-bottom: var(--space-sm);
  max-width: 18ch;
}

.contact__lead {
  font-size: var(--fs-lead);
  color: var(--text-muted);
  max-width: 52ch;
  margin-bottom: var(--space-md);
}

.contact__links {
  display: flex;
  gap: var(--space-sm);
  margin-top: var(--space-md);
}

.contact__links a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3rem;
  height: 3rem;
  border-radius: var(--radius-pill);
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 1.1rem;
  transition: transform var(--t-fast) var(--ease-out),
              color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out),
              background-color var(--t-fast) var(--ease-out);
}

.contact__links a:hover {
  transform: translateY(-3px);
  color: var(--accent-contrast);
  background: var(--accent);
  border-color: var(--accent);
}

/* -------------------------------------------------------------
   18. Footer
   ------------------------------------------------------------- */
.footer {
  border-top: 1px solid var(--border);
  padding-block: var(--space-lg);
  text-align: center;
}

.footer p {
  font-size: var(--fs-small);
  color: var(--text-faint);
}

/* -------------------------------------------------------------
   19. Modal (native dialog)
   ------------------------------------------------------------- */
.modal {
  margin: auto;
  width: min(92vw, 560px);
  padding: 0;
  border: none;
  background: transparent;
  color: var(--text);
  overflow: visible;
}

.modal::backdrop {
  background: rgba(6, 9, 13, 0.62);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.modal__card {
  position: relative;
  padding: clamp(1.6rem, 1.1rem + 2.5vw, 2.6rem);
  background: var(--surface-1);
  border: 1px solid var(--border-strong);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  border-top: 3px solid var(--accent);
}

.modal[open] .modal__card {
  animation: modal-in 320ms var(--ease-out) both;
}

@keyframes modal-in {
  from { opacity: 0; transform: translateY(14px) scale(0.98); }
  to   { opacity: 1; transform: translateY(0) scale(1); }
}

.modal__close {
  position: absolute;
  top: var(--space-sm);
  right: var(--space-sm);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.2rem;
  height: 2.2rem;
  border: 1px solid var(--border);
  background: var(--surface-2);
  color: var(--text-muted);
  border-radius: var(--radius-pill);
  font-size: 0.9rem;
  transition: color var(--t-fast) var(--ease-out),
              border-color var(--t-fast) var(--ease-out),
              transform var(--t-fast) var(--ease-out);
}

.modal__close:hover {
  color: var(--accent);
  border-color: var(--accent);
  transform: rotate(90deg);
}

.modal__date {
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
}

.modal__name {
  font-size: clamp(1.5rem, 1.2rem + 1.5vw, 2rem);
  margin: var(--space-2xs) 0 var(--space-xs);
  max-width: 22ch;
}

.modal__type {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: var(--space-md);
}

.modal__type i {
  color: var(--accent);
}

.modal__story {
  font-size: var(--fs-body);
  line-height: 1.7;
  color: var(--text);
  font-style: italic;
  padding: var(--space-sm) 0 var(--space-sm) var(--space-md);
  border-left: 3px solid var(--accent);
  background: var(--accent-soft);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

/* -------------------------------------------------------------
   26. Peer review — interactive flip cards
   ------------------------------------------------------------- */
.review-cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-md);
  perspective: 1200px;
}

.review-card {
  height: 220px;
  cursor: pointer;
}

.review-card__inner {
  position: relative;
  width: 100%;
  height: 100%;
  transition: transform 600ms var(--ease-out);
  transform-style: preserve-3d;
}

.review-card:hover .review-card__inner {
  transform: rotateY(180deg);
}

.review-card__front,
.review-card__back {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-xs);
  padding: var(--space-md);
  border-radius: var(--radius-md);
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.review-card__front {
  background: var(--surface-2);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-md);
}

.review-card__back {
  background: var(--accent);
  color: var(--accent-contrast);
  border: 1px solid var(--accent-strong);
  box-shadow: var(--shadow-accent);
  transform: rotateY(180deg);
}

.review-card__icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 3.5rem;
  height: 3.5rem;
  border-radius: var(--radius-md);
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 1.5rem;
  margin-bottom: var(--space-2xs);
}

.review-card__conf {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  font-weight: 700;
  color: var(--text);
  text-align: center;
}

.review-card__year {
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text-faint);
}

.review-card__role {
  font-family: var(--font-display);
  font-size: var(--fs-small);
  font-weight: 700;
  text-align: center;
}

.review-card__count {
  font-family: var(--font-display);
  font-size: clamp(1.4rem, 1rem + 1.5vw, 1.8rem);
  font-weight: 800;
  text-align: center;
}

.review-card__topics {
  font-size: var(--fs-eyebrow);
  font-weight: 500;
  opacity: 0.85;
  text-align: center;
}

/* Summary stat below cards */
.review-summary {
  display: flex;
  justify-content: center;
  margin-top: var(--space-lg);
}

.review-summary__stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-2xs);
  padding: var(--space-md) var(--space-xl);
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.review-summary__num {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: var(--fs-stat);
  color: var(--accent);
  line-height: 1;
}

.review-summary__label {
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* Contact buttons row */
.contact__buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-sm);
}

/* -------------------------------------------------------------
   20. Responsive — larger viewports
   ------------------------------------------------------------- */
@media (min-width: 720px) {
  .stats__grid {
    grid-template-columns: repeat(4, 1fr);
  }

  .hero__metrics {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 900px) {
  .hero__inner {
    grid-template-columns: 1.2fr 0.8fr;
    gap: var(--space-xl);
  }

  .hero__content {
    text-align: left;
  }

  .hero__tags {
    justify-content: flex-start;
  }

  .hero__metrics {
    justify-content: flex-start;
  }

  .hero__media {
    max-width: 400px;
    justify-self: end;
  }

  .about {
    grid-template-columns: 1fr;
    gap: var(--space-xl);
    align-items: center;
  }
}

/* -------------------------------------------------------------
   21. Responsive — small viewports
   ------------------------------------------------------------- */
@media (max-width: 760px) {
  .nav__links {
    display: none;
  }

  .events {
    grid-template-columns: 1fr;
  }

  .review-cards {
    grid-template-columns: 1fr;
  }

  .hero__metrics {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero__tags {
    flex-wrap: wrap;
  }
}

@media (max-width: 460px) {
  .stats__grid {
    grid-template-columns: 1fr;
  }

  .nav__cta {
    display: none;
  }
}

/* -------------------------------------------------------------
   22. Reduced motion — mandatory fallback
   ------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    transition-delay: 0ms !important;
    scroll-behavior: auto !important;
  }

  /* Reveal elements must be fully visible without JS or transition */
  [data-reveal],
  [data-reveal].is-revealed {
    opacity: 1 !important;
    transform: none !important;
    transition: none !important;
  }

  .modal[open] .modal__card {
    animation: none !important;
  }
}

/* -------------------------------------------------------------
   23. (Removed — old stat transit animation no longer used)
   ------------------------------------------------------------- */

/* -------------------------------------------------------------
   24. Research & publications
   ------------------------------------------------------------- */
.research {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}

.pub {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: var(--space-2xs);
  padding: var(--space-md);
  background: var(--surface-1);
  border: 1px solid var(--border);
  border-left: 3px solid var(--accent);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--t-mid) var(--ease-out),
              border-color var(--t-mid) var(--ease-out),
              box-shadow var(--t-mid) var(--ease-out);
}

.pub:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

/* Service entries (reviewing, book review) read as supporting, slightly quieter */
.pub--service {
  border-left-color: var(--border-strong);
  background: var(--surface-2);
}

.pub__venue {
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.pub--service .pub__venue {
  color: var(--text-faint);
}

.pub__title {
  font-family: var(--font-display);
  font-size: var(--fs-h3);
  font-weight: 600;
  line-height: 1.25;
  color: var(--text);
}

.pub__authors {
  font-size: var(--fs-small);
  color: var(--text-muted);
}

.pub__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45em;
  margin-top: var(--space-2xs);
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-small);
  color: var(--accent);
}

.pub__link i { transition: transform var(--t-fast) var(--ease-out); }
.pub:hover .pub__link:not(.pub__link--muted) i { transform: translate(3px, -3px); }

.pub__link--muted {
  color: var(--text-faint);
  font-weight: 500;
}

/* -------------------------------------------------------------
   25. (Reserved — old social rail removed, now inline profile badges)
   ------------------------------------------------------------- */

/* (old creds strip removed — replaced by hero__metrics) */

/* Greyed-out publication (in-progress / under review, de-emphasized) */
.pub--muted {
  background: var(--surface-2);
  border-left-color: var(--border-strong);
  opacity: 0.7;
}

.pub--muted .pub__venue { color: var(--text-faint); }
.pub--muted .pub__title { color: var(--text-muted); }
.pub--muted .pub__authors { color: var(--text-faint); }

/* Highlighted section (Industry Publications sits under Peer Review) */
.section--highlight {
  max-width: none;
  background:
    linear-gradient(180deg, var(--accent-soft), transparent 55%),
    var(--surface-1);
  border-block: 1px solid var(--border);
  position: relative;
}

.section--highlight::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--accent), transparent 70%);
}

.section--highlight > * {
  max-width: var(--container);
  margin-inline: auto;
}

/* Casual-download deterrent for photos. Not real protection:
   anything that renders can still be captured. Real protection =
   watermark + downscale the files committed to the public repo. */
.event__photo img,
.hero__photo img,
.about__media img {
  -webkit-user-select: none;
  user-select: none;
  -webkit-user-drag: none;
  pointer-events: none; /* clicks pass to the card button, not the image */
}

/* Transparent shield over event photos so long-press / save-as
   grabs the overlay, not the underlying image. */
.event__photo::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 3;
}

/* Hide the dev filename text in empty event placeholders.
   Picture-less cards now show just a clean icon. */
.event__ph-name { display: none; }

.event__ph i { font-size: 1.8rem; opacity: 0.5; }

/* Hide the generic source tags on post cards (e.g. "AI Blog · 2025") */
.post__tag { display: none; }

/* IEEE metric as a clickable link */
.metric--link { text-decoration: none; color: inherit; cursor: pointer; transition: transform var(--t-fast) var(--ease-out), border-color var(--t-fast) var(--ease-out); }
.metric--link:hover { transform: translateY(-3px); border-color: var(--accent); }

/* Featured publication card (the peer-reviewed IEEE paper) */
.post--featured {
  border-color: var(--accent);
  box-shadow: var(--shadow-md);
  background:
    linear-gradient(180deg, var(--accent-soft), transparent 60%),
    var(--surface-1);
}

.post__flag {
  display: inline-flex;
  align-items: center;
  gap: 0.45em;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

/* Book review card: show the full book title (smaller than the big count) */
.review-card--book .review-card__count {
  font-size: 1.05rem;
  line-height: 1.25;
}

/* "Areas of expertise" label above the hero tags */
.hero__tags-label {
  display: block;
  width: 100%;
  font-family: var(--font-display);
  font-size: var(--fs-eyebrow);
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text-faint);
  margin-bottom: 0.55rem;
}