/* ============================================
   Mark Vos — Speaker Website
   Dark premium theme
   ============================================ */

/* --- Reset & Base --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

:root {
  --bg-primary: #0d0d1a;
  --bg-secondary: #131328;
  --bg-card: #1a1a2e;
  --bg-card-hover: #222240;
  --accent: #00b4d8;
  --accent-dark: #0096b7;
  --accent-glow: rgba(0, 180, 216, 0.15);
  --text-primary: #f0f0f5;
  --text-secondary: #a0a0b8;
  --text-muted: #6b6b80;
  --border: #2a2a45;
  --white: #ffffff;
  --nav-height: 72px;
  --max-width: 1200px;
  --transition: 0.3s ease;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--white);
}

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

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
  font-family: 'Inter', sans-serif;
  font-weight: 700;
  line-height: 1.2;
  color: var(--white);
}

h1 { font-size: clamp(2.2rem, 5vw, 3.5rem); }
h2 { font-size: clamp(1.8rem, 4vw, 2.8rem); }
h3 { font-size: clamp(1.3rem, 3vw, 1.8rem); }
h4 { font-size: 1.25rem; }

p {
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.lead {
  font-size: 1.2rem;
  color: var(--text-primary);
  line-height: 1.8;
}

.label {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  display: block;
  margin-bottom: 1rem;
}

/* --- Layout --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
}

.section {
  padding: 6rem 0;
}

.section--alt {
  background-color: var(--bg-secondary);
}

.section--dark {
  background-color: var(--bg-primary);
}

/* --- Navigation --- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: var(--nav-height);
  background: rgba(13, 13, 26, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  z-index: 1000;
  border-bottom: 1px solid rgba(42, 42, 69, 0.5);
  transition: background var(--transition);
}

.nav__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 2rem;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--white);
}
.nav__logo:hover { color: var(--accent); }

.nav__links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav__links a {
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-secondary);
  transition: color var(--transition);
  position: relative;
}

.nav__links a::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: width var(--transition);
}

.nav__links a:hover,
.nav__links a.active {
  color: var(--white);
}

.nav__links a:hover::after,
.nav__links a.active::after {
  width: 100%;
}

/* Mobile nav toggle */
.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: 4px;
  background: none;
  border: none;
}

.nav__toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  transition: var(--transition);
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  padding: 0.9rem 2rem;
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 1.5px;
  text-transform: uppercase;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition);
  border: none;
  text-align: center;
}

.btn--primary {
  background: var(--accent);
  color: var(--bg-primary);
}
.btn--primary:hover {
  background: var(--white);
  color: var(--bg-primary);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 180, 216, 0.3);
}

.btn--outline {
  background: transparent;
  color: var(--accent);
  border: 1px solid var(--accent);
}
.btn--outline:hover {
  background: var(--accent);
  color: var(--bg-primary);
  transform: translateY(-2px);
}

.btn--ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1px solid var(--border);
}
.btn--ghost:hover {
  border-color: var(--accent);
  color: var(--accent);
}

.btn-group {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  margin-top: 2rem;
}

/* --- Hero Sections --- */
.hero {
  position: relative;
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
  overflow: hidden;
}

.hero--full {
  min-height: 100vh;
}

.hero--short {
  min-height: 50vh;
}

.hero__bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 0;
}

.hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.hero__bg::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    to bottom,
    rgba(13, 13, 26, 0.6) 0%,
    rgba(13, 13, 26, 0.85) 60%,
    var(--bg-primary) 100%
  );
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: 800px;
}

.hero__name {
  font-size: clamp(1rem, 2vw, 1.2rem);
  font-weight: 600;
  letter-spacing: 6px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.hero__credentials {
  font-size: 0.85rem;
  font-weight: 400;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.hero__quote {
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  font-weight: 800;
  line-height: 1.15;
  color: var(--white);
  margin-bottom: 1rem;
  max-width: 800px;
  letter-spacing: -0.5px;
}

.hero__quote em {
  font-style: normal;
  color: var(--accent);
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.35rem);
  font-weight: 300;
  color: var(--text-muted);
  margin-bottom: 2rem;
  max-width: 700px;
  letter-spacing: 0.5px;
}

/* --- Media Logo Bar --- */
.logo-bar {
  padding: 3rem 0;
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.logo-bar__label {
  text-align: center;
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 2rem;
}

.logo-bar__grid {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 2.5rem 3rem;
}

.logo-bar__item {
  opacity: 0.6;
  transition: opacity var(--transition);
  height: 40px;
  width: auto;
}

.logo-bar__item:hover {
  opacity: 0.9;
}

.logo-bar__item img {
  height: 100%;
  width: auto;
  filter: brightness(0) invert(1);
}

/* --- Two Column Split --- */
.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.split--reverse {
  direction: rtl;
}
.split--reverse > * {
  direction: ltr;
}

/* --- Topic Grid --- */
.topic-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.topic-column__header {
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--accent);
}

.topic-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
  padding: 1.5rem;
  margin-bottom: 1rem;
  transition: all var(--transition);
  cursor: default;
}

.topic-card:hover {
  border-color: var(--accent);
  background: var(--bg-card-hover);
  transform: translateY(-2px);
}

.topic-card__number {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.5rem;
}

.topic-card__title {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--white);
  line-height: 1.4;
}

/* --- Credential Stack --- */
.credential-stack {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1.5rem;
}

.credential-item {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  padding: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 6px;
}

.credential-item__icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  width: 40px;
  text-align: center;
}

.credential-item__text {
  font-size: 0.95rem;
  color: var(--text-primary);
}

.credential-item__text strong {
  display: block;
  color: var(--white);
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.credential-item__text span {
  color: var(--text-secondary);
  font-size: 0.85rem;
}

/* --- Book Feature --- */
.book-feature {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 3rem;
  align-items: center;
}

.book-cover {
  max-width: 350px;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.5), 0 8px 24px rgba(0, 0, 0, 0.3);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.book-cover:hover {
  transform: translateY(-4px);
  box-shadow: 0 28px 70px rgba(0, 0, 0, 0.6), 0 12px 32px rgba(0, 0, 0, 0.4);
}

.book-cover img {
  width: 100%;
  height: auto;
  display: block;
}

/* --- CTA Section --- */
.cta-section {
  text-align: center;
  padding: 6rem 0;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  border-top: 1px solid var(--border);
}

.cta-section h2 {
  margin-bottom: 1rem;
}

.cta-section p {
  max-width: 600px;
  margin: 0 auto 1rem;
}

/* --- Footer --- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  padding: 4rem 0 2rem;
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 3rem;
  margin-bottom: 3rem;
}

.footer__brand {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--white);
  margin-bottom: 1rem;
}

.footer__desc {
  font-size: 0.85rem;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 1rem;
}

.footer__heading {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 1rem;
}

.footer__links {
  list-style: none;
}

.footer__links li {
  margin-bottom: 0.5rem;
}

.footer__links a {
  font-size: 0.85rem;
  color: var(--text-muted);
}
.footer__links a:hover {
  color: var(--accent);
}

.footer__bottom {
  border-top: 1px solid var(--border);
  padding-top: 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.footer__social {
  display: flex;
  gap: 1rem;
}

.footer__social a {
  color: var(--text-muted);
  font-size: 0.85rem;
}

/* --- Video Embed --- */
.video-wrapper {
  position: relative;
  padding-bottom: 56.25%;
  height: 0;
  overflow: hidden;
  border-radius: 6px;
  border: 1px solid var(--border);
  background: var(--bg-card);
}

.video-wrapper iframe {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border: 0;
}

.video-wrapper .video-thumb {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
}

.video-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-thumb .play-btn {
  position: absolute;
  width: 68px;
  height: 48px;
  background: rgba(0, 0, 0, 0.75);
  border-radius: 14px;
  transition: background 0.2s ease, transform 0.2s ease;
}

.video-thumb:hover .play-btn {
  background: #e00;
  transform: scale(1.1);
}

.play-btn::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-35%, -50%);
  border-style: solid;
  border-width: 10px 0 10px 18px;
  border-color: transparent transparent transparent #fff;
}

/* --- Video Gallery --- */
.video-gallery {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 2rem;
}

.video-gallery__item h4 {
  margin-top: 1rem;
  font-size: 1rem;
  font-weight: 600;
}

.video-gallery__item p {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Keynote Detail Cards --- */
.keynote-detail {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3rem;
  margin-bottom: 2rem;
  transition: border-color var(--transition);
}

.keynote-detail:hover {
  border-color: var(--accent);
}

.keynote-detail__title {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--accent);
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

.keynote-detail__subtitle {
  font-size: 1rem;
  color: var(--text-muted);
  font-style: italic;
  margin-bottom: 1.5rem;
}

.keynote-detail__body p {
  margin-bottom: 1rem;
  line-height: 1.8;
}

.keynote-detail__takeaways {
  margin: 2rem 0;
  padding: 1.5rem;
  background: rgba(0, 180, 216, 0.05);
  border-left: 3px solid var(--accent);
  border-radius: 0 6px 6px 0;
}

.keynote-detail__takeaways h4 {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 1rem;
}

.keynote-detail__takeaways ul {
  list-style: none;
  padding: 0;
}

.keynote-detail__takeaways li {
  padding: 0.5rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-secondary);
  line-height: 1.6;
  font-size: 0.95rem;
}

.keynote-detail__takeaways li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 1rem;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent);
}

.keynote-detail__audience {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 1.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}

.keynote-detail__audience strong {
  color: var(--text-secondary);
}

/* --- Research Cards --- */
.research-card {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 2rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  overflow: hidden;
  margin-bottom: 2rem;
  transition: all var(--transition);
}

.research-card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.research-card__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  min-height: 180px;
}

.research-card__content {
  padding: 2rem 2rem 2rem 0;
}

.research-card__date {
  font-size: 0.8rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  margin-bottom: 0.5rem;
}

.research-card__title {
  font-size: 1.2rem;
  font-weight: 700;
  color: var(--white);
  margin-bottom: 0.75rem;
  line-height: 1.4;
}

/* --- Press Timeline --- */
.press-item {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 2rem;
  padding: 2rem 0;
  border-bottom: 1px solid var(--border);
}

.press-item__source {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--white);
  text-transform: uppercase;
  letter-spacing: 1px;
}

.press-item__date {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-top: 0.25rem;
}

.press-item__title {
  font-size: 1rem;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.press-item__desc {
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* --- Contact Form --- */
.form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.form-group {
  margin-bottom: 0;
}

.form-group--full {
  grid-column: 1 / -1;
}

.form-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 600;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--text-secondary);
  margin-bottom: 0.5rem;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.9rem 1rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  color: var(--text-primary);
  font-family: inherit;
  font-size: 0.95rem;
  transition: border-color var(--transition);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

.form-group textarea {
  resize: vertical;
  min-height: 140px;
}

.form-group select {
  -webkit-appearance: none;
  -moz-appearance: none;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23a0a0b8' viewBox='0 0 16 16'%3E%3Cpath d='M7.247 11.14L2.451 5.658C1.885 5.013 2.345 4 3.204 4h9.592a1 1 0 0 1 .753 1.659l-4.796 5.48a1 1 0 0 1-1.506 0z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 1rem center;
  background-size: 12px;
  padding-right: 2.5rem;
  cursor: pointer;
}

.form-group select option {
  background: var(--bg-card);
  color: var(--text-primary);
}

/* --- Contact Split --- */
.contact-options {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
}

.contact-option {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 3rem;
  text-align: center;
}

.contact-option h3 {
  margin-bottom: 1rem;
}

.contact-option p {
  margin-bottom: 1.5rem;
}

/* --- Quick Info --- */
.quick-info {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 2rem;
  text-align: center;
  padding: 3rem 0;
  border-top: 1px solid var(--border);
  margin-top: 4rem;
}

.quick-info__item strong {
  display: block;
  font-size: 0.75rem;
  letter-spacing: 2px;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 0.5rem;
}

.quick-info__item span {
  color: var(--text-primary);
  font-size: 0.95rem;
}

/* --- Career Logos --- */
.career-logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 3rem;
}

.career-logos img {
  height: 40px;
  width: auto;
  opacity: 0.6;
  transition: opacity var(--transition);
  filter: brightness(0) invert(1);
}

.career-logos img:hover {
  opacity: 1;
}

/* --- Findings List --- */
.findings-list {
  list-style: none;
  padding: 0;
}

.findings-list li {
  padding: 1rem 0 1rem 2rem;
  position: relative;
  color: var(--text-secondary);
  line-height: 1.7;
  border-bottom: 1px solid var(--border);
}

.findings-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 1.35rem;
  width: 8px;
  height: 8px;
  border: 2px solid var(--accent);
  border-radius: 50%;
}

/* --- Section Divider --- */
.divider {
  width: 60px;
  height: 3px;
  background: var(--accent);
  margin: 2rem 0;
}

/* --- Custom Engagement --- */
.engagement-list {
  list-style: none;
  padding: 0;
}

.engagement-list li {
  padding: 1rem 0;
  padding-left: 1.5rem;
  position: relative;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--border);
}

.engagement-list li::before {
  content: '→';
  position: absolute;
  left: 0;
  color: var(--accent);
  font-weight: 700;
}

.engagement-list li strong {
  color: var(--text-primary);
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Scrolled Nav State --- */
.nav--scrolled {
  background: rgba(13, 13, 26, 0.98);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

/* --- Mobile Responsive --- */
@media (max-width: 968px) {
  .nav__links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    width: 100%;
    background: rgba(13, 13, 26, 0.98);
    backdrop-filter: blur(20px);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all 0.4s ease;
    border-bottom: 1px solid var(--border);
  }

  .nav__links.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .nav__toggle {
    display: flex;
  }

  .nav__toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }
  .nav__toggle.active span:nth-child(2) {
    opacity: 0;
  }
  .nav__toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .split {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .split--reverse {
    direction: ltr;
  }

  .topic-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .book-feature {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .book-cover {
    max-width: 280px;
    margin: 0 auto;
  }

  .footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
  }

  .video-gallery {
    grid-template-columns: 1fr;
  }

  .contact-options {
    grid-template-columns: 1fr;
  }

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

  .quick-info {
    grid-template-columns: 1fr 1fr;
  }

  .press-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .research-card {
    grid-template-columns: 1fr;
  }

  .research-card__image {
    min-height: 200px;
  }

  .research-card__content {
    padding: 0 2rem 2rem;
  }

  .credential-stack {
    grid-template-columns: 1fr;
  }

  .hero {
    min-height: 70vh;
  }

  .section {
    padding: 4rem 0;
  }
}

@media (max-width: 600px) {
  .container {
    padding: 0 1.25rem;
  }

  .hero__quote {
    font-size: 1.8rem;
  }

  .hero__subtitle {
    font-size: 0.95rem;
  }

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

  .footer__bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  .quick-info {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .keynote-detail {
    padding: 2rem 1.5rem;
  }

  .logo-bar__grid {
    gap: 1.5rem 2rem;
  }

  .career-logos {
    gap: 2rem;
  }

  .career-logos img {
    height: 30px;
  }
}

/* --- Retailer Button Grid --- */
.retailer-grid {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.retailer-btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 4px;
  text-decoration: none;
  transition: all var(--transition);
  letter-spacing: 0.5px;
}

.retailer-btn:hover {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
  transform: translateY(-2px);
  box-shadow: 0 4px 16px rgba(0, 180, 216, 0.25);
}

/* --- Hardcover Purchase --- */
.hardcover-section {
  background: linear-gradient(135deg, rgba(0, 180, 216, 0.06) 0%, rgba(19, 19, 40, 0.4) 100%);
  border: 1px solid rgba(0, 180, 216, 0.2);
  border-radius: 8px;
  padding: 2.5rem;
  margin-bottom: 2.5rem;
  text-align: center;
}

.hardcover-section h3 {
  font-size: 0.8rem;
  font-weight: 700;
  letter-spacing: 3px;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: 0.75rem;
}

.hardcover-section .hardcover-desc {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-bottom: 1.5rem;
}

.hardcover-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1rem;
  margin-bottom: 1.25rem;
}

.hardcover-btn {
  display: inline-block;
  padding: 1rem 2rem;
  font-size: 0.9rem;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--bg-primary);
  background: var(--accent);
  border: 2px solid var(--accent);
  border-radius: 4px;
  text-decoration: none;
  transition: all var(--transition);
}

.hardcover-btn:hover {
  background: var(--white);
  color: var(--bg-primary);
  border-color: var(--white);
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(0, 180, 216, 0.3);
}

.hardcover-btn--intl {
  background: transparent;
  color: var(--accent);
}

.hardcover-btn--intl:hover {
  background: var(--accent);
  color: var(--bg-primary);
  border-color: var(--accent);
}

.hardcover-meta {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

.hardcover-meta .payment-methods {
  margin-top: 0.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.5px;
}

.preorder-note {
  display: inline-block;
  margin-top: 1rem;
  margin-bottom: 0.25rem;
  padding: 0.6rem 1.25rem;
  font-size: 0.82rem;
  color: rgba(0, 180, 216, 0.85);
  background: rgba(0, 180, 216, 0.07);
  border-radius: 4px;
  letter-spacing: 0.3px;
  line-height: 1.5;
}

/* --- Utility --- */
.text-center { text-align: center; }
.mb-1 { margin-bottom: 1rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-3 { margin-bottom: 3rem; }
.mb-4 { margin-bottom: 4rem; }
.mt-2 { margin-top: 2rem; }
.mt-3 { margin-top: 3rem; }
.mt-4 { margin-top: 4rem; }