/* ===== Light theme (default) ===== */
:root {
  --color-primary: #002147;
  --color-accent-1: #75b2dd;
  --color-accent-2: #b39c4d;
  --color-secondary: #768948;
  --color-neutral: #313131;

  --header-bg: #1a1a1a;
  --footer-bg: #002147;

  --bg: #eff1f4;
  --bg-elevated: #f8f9fb;
  --section-bg: #e2e5ea;
  --section-card-bg: #ffffff;

  --text: #1d242c;
  --text-muted: #4d5a6a;

  --border: rgba(0, 33, 71, 0.14);
  --border-accent: rgba(117, 178, 221, 0.30);
  --shadow: 0 4px 24px rgba(0, 33, 71, 0.08);
  --focus: 0 0 0 3px rgba(117, 178, 221, 0.4);

  --input-bg: #ffffff;
  --input-border: rgba(0, 33, 71, 0.18);

  --radius-lg: 18px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --max-width: 1200px;
  --font-family: "Roboto", "Inter", system-ui, -apple-system, "Segoe UI", sans-serif;
  --text-size: 16px;
  --line-height: 1.65;
}

/* ===== Dark theme ===== */
[data-theme="dark"] {
  --bg: #121417;
  --bg-elevated: #1a1d21;
  --section-bg: #16181c;
  --section-card-bg: #1e2025;
  --text: #e1e2e5;
  --text-muted: #8b909a;
  --border: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(117, 178, 221, 0.22);
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
  --input-bg: rgba(255, 255, 255, 0.06);
  --input-border: rgba(117, 178, 221, 0.22);
}

/* System dark preference (no-JS fallback) */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --bg: #121417;
    --bg-elevated: #1a1d21;
    --section-bg: #16181c;
    --section-card-bg: #1e2025;
    --text: #e1e2e5;
    --text-muted: #8b909a;
    --border: rgba(255, 255, 255, 0.08);
    --border-accent: rgba(117, 178, 221, 0.22);
    --shadow: 0 4px 24px rgba(0, 0, 0, 0.4);
    --input-bg: rgba(255, 255, 255, 0.06);
    --input-border: rgba(117, 178, 221, 0.22);
  }
}

[data-text-size="xs"] {
  --text-size: 14px;
}

[data-text-size="sm"] {
  --text-size: 15px;
}

[data-text-size="md"] {
  --text-size: 16px;
}

[data-text-size="lg"] {
  --text-size: 17.5px;
}

[data-text-size="xl"] {
  --text-size: 19px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: var(--text-size);
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  line-height: var(--line-height);
  color: var(--text);
  background: var(--bg);
  min-height: 100vh;
}

h1,
h2,
h3 {
  letter-spacing: 0.02em;
}

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

a {
  color: var(--color-accent-1);
  text-decoration: none;
}

a:hover {
  color: #a3d0ec;
}

button,
select,
input,
textarea {
  font-family: inherit;
  font-size: inherit;
}

.container {
  width: min(100% - 2rem, var(--max-width));
  margin: 0 auto;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-accent-2);
  color: #000;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  z-index: 10;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  outline: none;
  box-shadow: var(--focus);
}

.site-header {
  background: var(--header-bg);
  color: #f1f1f1;
  position: sticky;
  top: 0;
  z-index: 20;
  border-bottom: 1px solid var(--border-accent);
}

.site-header .nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1rem 0;
  gap: 1rem;
  flex-wrap: nowrap;
}

.brand {
  display: flex;
  flex-direction: column;
  gap: 0.2rem;
}

.brand a {
  color: #ffffff;
  font-weight: 700;
  letter-spacing: 0.03em;
}

.brand span {
  font-size: 0.85rem;
  color: rgba(255, 255, 255, 0.6);
}

.nav-links {
  list-style: none;
  display: flex;
  gap: 1rem;
  flex-wrap: nowrap;
}

.nav-links a {
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
}

.nav-links a:hover,
.nav-links a[aria-current="page"] {
  color: var(--color-accent-1);
}

.footer-controls {
  display: grid;
  gap: 0.75rem;
  padding: 0.9rem;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  min-width: 220px;
}

.footer-controls label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.65);
}

.footer-controls select,
.footer-controls button,
.footer-controls input[type="range"] {
  border: 1px solid var(--border-accent);
  background: transparent;
  color: #f1f1f1;
  padding: 0.35rem 0.6rem;
  border-radius: 8px;
}

.footer-controls button {
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
  font-weight: 600;
  color: #f1f1f1;
}

.text-size-panel {
  display: grid;
  gap: 0.4rem;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height 0.25s ease, opacity 0.25s ease;
}

.text-size-panel[data-open="true"] {
  max-height: 120px;
  opacity: 1;
}

.text-size-scale {
  display: flex;
  justify-content: space-between;
  font-size: 0.7rem;
  color: var(--text-muted);
}

.footer-controls .text-size-scale {
  color: rgba(255, 255, 255, 0.6);
}

.hero {
  position: relative;
  min-height: 70vh;
  display: grid;
  align-items: center;
  background: var(--color-primary);
  color: #f6fbff;
  overflow: hidden;
}

.hero canvas {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
}

.hero-content {
  position: relative;
  z-index: 2;
  padding: 4rem 0;
  display: grid;
  gap: 1.8rem;
}

.hero h1 {
  font-size: clamp(2rem, 3vw, 3.2rem);
  max-width: 18ch;
}

.hero p {
  max-width: 52ch;
  color: rgba(246, 251, 255, 0.8);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.7rem 1.4rem;
  border-radius: 999px;
  border: 1px solid transparent;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.button.primary {
  background: var(--color-accent-2);
  color: #111;
  box-shadow: 0 10px 24px rgba(179, 156, 77, 0.35);
}

.button.secondary {
  background: transparent;
  color: var(--text);
  border-color: var(--color-accent-2);
}

.hero .button.secondary {
  color: #f6fbff;
}

.button:hover {
  transform: translateY(-2px);
}

.section {
  padding: 4rem 0;
}

.section-compact {
  padding: 2.5rem 0;
  background: var(--section-bg);
  color: var(--text);
  border-top: 1px solid var(--border-accent);
  border-bottom: 1px solid var(--border-accent);
}

.section-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
  margin-bottom: 2rem;
}

.section-compact .section-header {
  margin-bottom: 1rem;
}

.section-header h2 {
  font-size: clamp(1.6rem, 2.4vw, 2.2rem);
  color: var(--text);
}

.section-compact .section-header p {
  color: var(--text-muted);
}

.section-header p {
  color: var(--text-muted);
  max-width: 45ch;
}

.card-grid {
  display: grid;
  gap: 1.5rem;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
}

.section-compact .card-grid,
.section-compact .research-pillars {
  gap: 1rem;
}

.card {
  background: var(--bg-elevated);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 1.4rem;
  box-shadow: var(--shadow);
}

.section-compact .card,
.section-compact .pillar {
  background: var(--section-card-bg);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 1.1rem;
  box-shadow: var(--shadow);
}

.section-compact .card p {
  color: var(--text-muted);
}

.section-compact .pillar span {
  color: var(--color-accent-1);
}

.card h3 {
  margin-bottom: 0.6rem;
}

.card p {
  color: var(--text-muted);
}

.research-pillars {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 1.5rem;
}

.pillar {
  background: linear-gradient(150deg, rgba(117, 178, 221, 0.08), rgba(179, 156, 77, 0.06));
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 1.4rem;
}

.pillar h3 {
  color: var(--text);
  margin-bottom: 0.4rem;
}

.pillar span {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-weight: 600;
  color: var(--color-accent-1);
}

/* Research rows — full-width stacked layout */
.research-rows {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.research-row {
  display: grid;
  grid-template-columns: 140px 1fr;
  background: var(--section-card-bg);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.research-row-label {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.2rem 0.8rem;
  font-weight: 700;
  font-size: 0.82rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent-1);
  background: rgba(117, 178, 221, 0.07);
  border-right: 2px solid var(--border-accent);
  text-align: center;
  line-height: 1.3;
}

.research-row-body {
  padding: 1.2rem 1.4rem;
}

.research-row-body h3 {
  margin: 0 0 0.5rem;
  font-size: 1.05rem;
}

.research-row-body p {
  color: var(--text-muted);
  margin: 0 0 0.6rem;
  line-height: 1.55;
}

.research-row-body ul {
  margin: 0;
  padding-left: 1.2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  line-height: 1.65;
}

.research-row-body ul li::marker {
  color: var(--color-accent-2);
}

@media (max-width: 600px) {
  .research-row {
    grid-template-columns: 1fr;
  }
  .research-row-label {
    border-right: none;
    border-bottom: 2px solid var(--border-accent);
    padding: 0.8rem;
  }
}

/* Lab rooms */
.lab-rooms {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
  margin-top: 1rem;
}

.lab-room {
  background: var(--section-card-bg);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 1.4rem;
}

.lab-room h3 {
  margin: 0 0 0.4rem;
  font-size: 1rem;
}

.lab-room .lab-meta {
  color: var(--text-muted);
  font-size: 0.88rem;
  margin: 0 0 0.6rem;
}

.lab-room p {
  color: var(--text-muted);
  margin: 0 0 0.7rem;
  line-height: 1.5;
}

.lab-room .lab-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  color: var(--color-accent-1);
  font-weight: 600;
  font-size: 0.88rem;
  text-decoration: none;
}

.lab-room .lab-link:hover {
  text-decoration: underline;
}

.tagline {
  font-weight: 600;
  color: var(--color-accent-2);
}

footer {
  background: var(--footer-bg);
  color: #ffffff;
  padding: 1.5rem 0;
  margin-top: 0;
  border-top: 1px solid var(--border-accent);
}

footer a {
  color: var(--color-accent-1);
}

footer a:hover {
  color: #ffffff;
}

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

.page-header {
  padding: 2.5rem 0 1rem;
}

.page-header h1 {
  font-size: clamp(2rem, 3vw, 2.6rem);
}

.profile-grid {
  display: grid;
  gap: 1.5rem;
}

.profile-card {
  background: var(--section-card-bg);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 1.4rem;
  display: grid;
  gap: 0.75rem;
}

.profile-card.large {
  border: 1px solid rgba(179, 156, 77, 0.6);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.3);
}

.avatar {
  width: 72px;
  height: 72px;
  aspect-ratio: 1 / 1;
  border-radius: 12px;
  background: linear-gradient(135deg, rgba(117, 178, 221, 0.35), rgba(179, 156, 77, 0.35));
  border: 1px solid rgba(117, 178, 221, 0.45);
  overflow: hidden;
}

.avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.profile-meta {
  display: grid;
  gap: 0.3rem;
}

.profile-meta a {
  color: var(--color-accent-1);
  font-weight: 500;
}

.profile-role {
  font-weight: 600;
  color: var(--color-accent-2);
}

.profile-section {
  display: grid;
  gap: 1.2rem;
}

.profile-section h2 {
  font-size: 1.2rem;
  border-bottom: 1px solid var(--border-accent);
  padding-bottom: 0.4rem;
}

.projects-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.projects-tabs button {
  border: 1px solid var(--border-accent);
  background: var(--section-card-bg);
  color: var(--text);
  padding: 0.5rem 1rem;
  border-radius: 999px;
  cursor: pointer;
}

.projects-tabs button.active {
  background: var(--color-accent-2);
  color: #111;
  border-color: transparent;
}

.project-card {
  display: grid;
  gap: 0.6rem;
}

.project-card span {
  color: var(--color-accent-1);
  font-weight: 600;
}

.contact-card {
  display: grid;
  gap: 1rem;
  background: var(--section-card-bg);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-md);
  padding: 1.6rem;
}

.contact-card form {
  display: grid;
  gap: 0.75rem;
}

.contact-card input,
.contact-card textarea {
  border: 1px solid var(--input-border);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
  background: var(--input-bg);
  color: var(--text);
}

.contact-card textarea {
  min-height: 120px;
  resize: vertical;
}

.contact-card button {
  justify-self: start;
}

@media (max-width: 900px) {
  .site-header .nav {
    flex-wrap: nowrap;
  }

  .brand span {
    display: none;
  }

  .nav-links {
    gap: 0.7rem;
  }

  .nav-links a {
    font-size: 0.9rem;
  }
}

@media (max-width: 700px) {
  .hero-content {
    padding: 3rem 0;
  }

  .hero-actions {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* Theme toggle */
.theme-toggle {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  border: 1px solid var(--border-accent);
  background: transparent;
  color: #f1f1f1;
  padding: 0.35rem 0.75rem;
  border-radius: 8px;
  cursor: pointer;
  font-weight: 600;
  font-size: 0.88rem;
  font-family: inherit;
  transition: background 0.2s ease;
}

.theme-toggle:hover {
  background: rgba(255, 255, 255, 0.08);
}

/* Override Hanoi page styles to match #002147 & #b39c4d palette when needed. */

/* Icon cards — used on home and I4.0 overview grids */
.icon-card {
  text-align: center;
  padding: 1.6rem 1.2rem;
}

.icon-card-icon {
  display: block;
  font-size: 1.8rem;
  margin-bottom: 0.6rem;
  line-height: 1;
}

.icon-card h3 {
  font-size: 1rem;
  margin-bottom: 0.45rem;
}

.card-grid-3x2 {
  grid-template-columns: repeat(3, 1fr);
}

@media (max-width: 700px) {
  .card-grid-3x2 {
    grid-template-columns: 1fr;
  }
}

/* Section CTA — centered button row under a card grid */
.section-cta {
  display: flex;
  justify-content: center;
  margin-top: 1.5rem;
}

/* Contact select */
.contact-card select {
  border: 1px solid var(--input-border);
  border-radius: 8px;
  padding: 0.6rem 0.8rem;
  background: var(--input-bg);
  color: var(--text);
  width: 100%;
  font-size: inherit;
}

/* Lab room images */
.lab-room-img {
  width: 100%;
  border-radius: var(--radius-sm);
  margin-bottom: 0.8rem;
  object-fit: cover;
  max-height: 180px;
}

/* Intro with side image (used on I4.0 hero) */
.intro-with-image {
  display: grid;
  grid-template-columns: 1fr 320px;
  gap: 2rem;
  align-items: start;
  margin-top: 1rem;
}

.intro-image {
  width: 100%;
  border-radius: var(--radius-md);
  object-fit: cover;
  max-height: 260px;
  box-shadow: var(--shadow);
}

@media (max-width: 700px) {
  .intro-with-image {
    grid-template-columns: 1fr;
  }
  .intro-image {
    max-height: 200px;
  }
}

/* Page header media — centered image under header text */
.page-header-media {
  margin-top: 1.2rem;
  display: flex;
  justify-content: center;
}

.page-header-img {
  width: 100%;
  max-width: 720px;
  border-radius: var(--radius-md);
  object-fit: cover;
  max-height: 340px;
  box-shadow: var(--shadow);
}