:root {

  --pink: #ff4da6;
  --light-pink: #ffa7d9;
  --purple: #7c4dff;
  --blue: #6c8cff;
  --dark-blue: #151a33;
  --darker-blue: #0e1226;
  --white: #ffffff;
  --gray-light: #1e2547;
  --gray: #2f3860;
  --text-dark: #e5e5f1;
  --text-muted: #a2a8d3;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI',
    Roboto, Helvetica, Arial, sans-serif;
  line-height: 1.6;

  font-size: 1.05rem;
  color: var(--text-dark);
  background-color: var(--darker-blue);
  overflow-x: hidden;
}

h1,
h2,
h3,
h4,
h5,
h6 {
  font-family: 'IBM Plex Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI',
    Roboto, Helvetica, Arial, sans-serif;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin: 0 0 0.75rem;
  color: inherit;
}
h1 {
  font-size: clamp(2.6rem, 5vw, 3.5rem);
  line-height: 1.1;
  font-weight: 700;
}
h2 {
  font-size: clamp(2.1rem, 3.8vw, 2.8rem);
  line-height: 1.2;
}
h3 {
  font-size: clamp(1.4rem, 3vw, 1.85rem);
  line-height: 1.3;
}
h4 {
  font-size: clamp(1.15rem, 2.2vw, 1.45rem);
  line-height: 1.35;
}
p,
li {
  font-size: 1.05rem;
  line-height: 1.7;
  color: inherit;
}
.section-heading {
  font-size: clamp(2.2rem, 3.6vw, 3rem);
  font-weight: 600;
  line-height: 1.2;
}
.fine-print,
small {
  font-size: 0.9rem;
  line-height: 1.5;
}

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

a {
  color: var(--blue);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}

.container {
  width: 90%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 2rem 0;
}

.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: 4px;
  font-weight: 600;
  cursor: pointer;
  transition: background-color 0.3s, box-shadow 0.3s;
  text-align: center;
}
.btn-primary {
  background-image: linear-gradient(90deg, var(--pink), var(--purple));
  color: var(--white);
  border: none;
}
.btn-primary:hover {
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.navbar {
  background-color: var(--dark-blue);
  border-bottom: 1px solid var(--gray);
  position: sticky;
  top: 0;
  z-index: 1000;
}
.nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 90%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0.5rem 0;
  position: relative;
}
.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.kcl-logo {

  height: 90px;
  width: auto;
}

.qiskit-logo {
  height: 100px;
  width: auto;
  margin-right: 0.5rem;
}
.nav-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--white);
}
.nav-links {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  margin: 0;
  padding: 0;
}
.nav-links li a {
  font-weight: 500;
  font-size: 0.95rem;
  color: var(--text-muted);
  padding: 0.5rem;
  border-radius: 4px;
  transition: background-color 0.2s, color 0.2s;
}
.nav-links li a:hover {
  background-color: var(--gray);
  color: var(--white);
}
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 5px;
  background: transparent;
  border: none;
  width: 44px;
  height: 44px;
  padding: 0;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.2s ease;
}
.nav-toggle:hover,
.nav-toggle:focus-visible {
  background-color: rgba(255, 255, 255, 0.08);
  outline: none;
}
.nav-toggle:focus-visible {
  box-shadow: 0 0 0 3px rgba(255, 77, 166, 0.35);
}
.nav-toggle span {
  width: 24px;
  height: 2px;
  background-color: var(--text-dark);
  transition: transform 0.3s ease, opacity 0.3s ease;
}
.nav-toggle.nav-open span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle.nav-open span:nth-child(2) {
  opacity: 0;
}
.nav-toggle.nav-open span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  background-color: var(--dark-blue);
  color: var(--text-dark);
  padding: 5rem 0 7rem;
  position: relative;
  overflow: hidden;
}
.hero-overlay {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(at top left, var(--purple) 0%, transparent 70%),
    radial-gradient(at bottom right, var(--pink) 0%, transparent 70%);
  opacity: 0.4;
}
.hero-content {
  position: relative;
  z-index: 2;
  width: 90%;
  max-width: 900px;
  margin: 0 auto;
  text-align: center;
}
.hero h1 {
  margin-top: 0;
  margin-bottom: 0.75rem;
  color: var(--white);
  font-size: clamp(2.8rem, 6vw, 3.8rem);
}
.hero p {
  margin-bottom: 1rem;
  color: var(--text-muted);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
}
.hero-dates {
  margin-bottom: 1.5rem;
  font-weight: 600;
  color: var(--light-pink);
}
.hero-badge {
  display: block;
  margin: 2rem auto 0;
  max-width: 180px;
  width: 100%;
  height: auto;
}
.hero-silhouette {
  position: absolute;
  left: 0;
  bottom: 0;
  width: 100%;
  z-index: 1;
  overflow: hidden;
}
.hero-silhouette img {
  width: 100%;
  height: auto;
  filter: invert(1) brightness(0.7);
  opacity: 0.3;

  transform: translateY(20%);
}

.about-section {
  background-color: var(--gray-light);
  border-top: 1px solid var(--gray);
  color: var(--text-dark);
}
.about-content {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 2rem;
}
.about-text {
  flex: 2 1 500px;
}
.about-text h2 {
  margin-top: 0;
  color: var(--white);
}
.about-text p {
  margin-bottom: 1rem;
  color: var(--text-muted);

  font-size: 1.05rem;
}
.fine-print {
  font-size: 0.9rem;
  color: var(--text-muted);
  font-style: italic;
}

.about-decor {
  margin-top: 1rem;
  max-width: 300px;
  width: 100%;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.2));
}
.about-badge {
  flex: 1 1 200px;
  text-align: center;
}
.badge-image {
  max-width: 200px;
  width: 100%;
  filter: drop-shadow(0 4px 8px rgba(0, 0, 0, 0.2));
}

.about-badge img {

  max-width: 520px;
  width: 100%;
}

.schedule-section {
  position: relative;
  padding-bottom: 4rem;
}
.schedule-section h2 {
  color: var(--white);
  margin-top: 0;
  margin-bottom: 0.75rem;
}
.schedule-section p {
  color: var(--text-muted);
}

.timeline {
  position: relative;
  margin: 2rem 0;
  padding-left: 40px;
  border-left: 2px solid var(--purple);
}
.timeline::after {
  content: '';
  position: absolute;
  left: 40px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: var(--purple);
  z-index: 0;
}

.timeline-columns {
  display: flex;
  flex-wrap: wrap;
  gap: 3rem;
  margin-top: 2rem;
}
.timeline-column {
  flex: 1 1 400px;
}
.timeline-column h3 {
  margin: 0 0 1rem;
  color: var(--light-pink);
}
.timeline-item {
  position: relative;
  margin-bottom: 2.5rem;
  padding-left: 1.5rem;
  display: flex;
  align-items: flex-start;
  z-index: 1;
}
.timeline-icon {
  position: absolute;

  left: -37px;
  top: 0;

  width: 80px;
  height: 80px;
  border-radius: 50%;
  background-color: var(--gray);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 6px rgba(0, 0, 0, 0.4);
}
.timeline-icon img {
  width: 52px;
  height: 52px;
}
.timeline-content {
  margin-left: 2rem;
  flex: 1;
}
.timeline-date {
  font-size: 0.85rem;
  color: var(--blue);
  margin-bottom: 0.2rem;
}
.timeline-title {
  margin: 0;
  font-size: clamp(1.35rem, 2.6vw, 1.8rem);
  color: var(--white);
}
.timeline-type {
  margin: 0;
  font-size: 0.9rem;
  color: var(--light-pink);
  font-weight: 600;
}

.speaker-link {
  color: var(--blue);
  font-weight: 700;
  text-decoration: none;
  transition: color 0.2s ease;
}

.speaker-link:hover,
.speaker-link:focus-visible {
  color: var(--light-pink);
  text-decoration: underline;
  outline: none;
}

.anchor-title {
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--blue);
  margin: 0 0 0.2rem;
}
.timeline-details {
  margin: 0.3rem 0 0.5rem;
  font-size: 0.9rem;
  color: var(--text-muted);
}
.timeline-item .register-btn {
  padding: 0.35rem 0.9rem;
  font-size: 0.85rem;
  border-radius: 4px;
  color: var(--white);
  background-image: linear-gradient(90deg, var(--pink), var(--purple));
  border: none;
  cursor: pointer;
}
.timeline-item .register-btn:hover {
  opacity: 0.9;
}

.promo-banner {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  padding: 0.6rem 1.25rem;
  flex-wrap: wrap;
  text-align: center;

  background-image: linear-gradient(90deg, var(--gray), var(--dark-blue));
  z-index: 3;
}

.promo-logo {
  height: 28px;
  width: auto;
}

.promo-tag-image {
  height: 32px;
  width: auto;
  margin-left: 0.5rem;
  flex-shrink: 0;
}

.promo-text .promo-tag-image {
  display: inline-block;
  vertical-align: middle;
  margin: 0 0.4rem;
}

.promo-text {
  color: var(--white);

  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.4;
}

.supported-section {
  background: linear-gradient(180deg, var(--dark-blue), var(--darker-blue));
  border-top: 1px solid var(--gray);
  padding: 3rem 0;
  text-align: center;
}
.supported-section h3 {
  margin-top: 0;
  margin-bottom: 1rem;
  color: var(--light-pink);
  font-size: clamp(1.4rem, 2.5vw, 1.8rem);
}
.supported-logos {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: clamp(1.5rem, 3vw, 3rem);
  background-color: rgba(255, 255, 255, 0.95);
  border-radius: 18px;
  padding: clamp(1.5rem, 3vw, 2.75rem) clamp(1.5rem, 5vw, 3.5rem);
  box-shadow: 0 30px 60px rgba(0, 0, 0, 0.28);
}
.supported-logo {
  height: clamp(48px, 6vw, 70px);
  width: auto;
  filter: none;
}

#preloader {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: 2000;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--darker-blue);
}

#preloader .loader-bg-image {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-image: url('images/simplified_illustration.png');
  background-size: cover;
  background-position: center;
  filter: brightness(0.9);
  z-index: 0;
}

#preloader .loader-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(5, 10, 25, 0.85);
  z-index: 1;
  animation: loaderReveal 2s linear infinite;
}
@keyframes loaderReveal {
  0%, 10% {
    transform: translateY(0%);
  }
  50% {
    transform: translateY(-100%);
  }
  90%, 100% {
    transform: translateY(0%);
  }
}

#preloader .loader-circuit {
  position: absolute;
  top: 40%;
  left: 50%;
  transform: translateX(-50%);
  width: 75%;
  max-width: 850px;
  height: 200px;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  z-index: 2;
  pointer-events: none;
}
#preloader .loader-circuit .line {
  position: relative;
  width: 100%;
  height: 4px;
  background: rgba(255, 255, 255, 0.12);
  border-radius: 2px;
  overflow: hidden;
}
#preloader .pulse {
  position: absolute;
  top: -6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: linear-gradient(45deg, #78caff, #cf6bff);
  box-shadow: 0 0 8px 2px rgba(133, 67, 255, 0.6);
}

#preloader .pulse1 { animation: loaderMove1 3s linear infinite; }
#preloader .pulse2 { animation: loaderMove2 3.2s linear infinite; }
#preloader .pulse3 { animation: loaderMove3 2.8s linear infinite; }
#preloader .pulse4 { animation: loaderMove4 3.4s linear infinite; }
#preloader .pulse5 { animation: loaderMove5 3.1s linear infinite; }
@keyframes loaderMove1 { from { left: -20px; } to { left: calc(100% + 20px); } }
@keyframes loaderMove2 { from { left: calc(-20px - 15%); } to { left: calc(100% + 20px); } }
@keyframes loaderMove3 { from { left: calc(-20px - 30%); } to { left: calc(100% + 20px); } }
@keyframes loaderMove4 { from { left: calc(-20px - 45%); } to { left: calc(100% + 20px); } }
@keyframes loaderMove5 { from { left: calc(-20px - 60%); } to { left: calc(100% + 20px); } }

#preloader .loader-badge {
  position: absolute;
  top: 15%;
  left: 50%;
  transform: translateX(-50%);
  width: 200px;
  height: 200px;
  border-radius: 50%;
  overflow: hidden;
  box-shadow: 0 0 20px rgba(190, 100, 255, 0.4);
  z-index: 2;
}
#preloader .loader-badge img {
  width: 100%;
  height: 100%;
  object-fit: contain;
}

#preloader .loader-tagline {
  position: absolute;
  top: 80%;
  left: 50%;
  transform: translate(-50%, -50%);
  z-index: 2;
  text-align: center;
}
#preloader .loader-tagline img {
  width: 380px;
  max-width: 90vw;
  object-fit: contain;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.6));
}

#preloader .progress-container {
  position: absolute;
  bottom: 60px;
  left: 50%;
  transform: translateX(-50%);
  width: 60%;
  max-width: 500px;
  height: 8px;
  background: rgba(255, 255, 255, 0.2);
  border-radius: 4px;
  overflow: hidden;
  z-index: 2;
}
#preloader .progress-bar {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #78caff, #cf6bff);
  border-radius: 4px;
  animation: loaderProgress 2s linear infinite;
}
@keyframes loaderProgress {
  from { width: 0%; }
  to { width: 100%; }
}

@media (max-width: 600px) {
  #preloader .loader-badge {
    width: 180px;
    height: 180px;
    top: 15%;
  }
  #preloader .loader-circuit {
    width: 90%;
    height: 200px;
    top: 40%;
  }
  #preloader .loader-tagline {
    top: 78%;
  }
  #preloader .loader-tagline img {
    width: 90vw;
  }
  #preloader .progress-container {
    width: 90%;
  }
}
@media (max-width: 400px) {
  #preloader .loader-badge {
    width: 160px;
    height: 160px;
  }
  #preloader .loader-circuit {
    height: 180px;
  }
}

.events-checkboxes {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.events-checkboxes label {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  cursor: pointer;
  color: var(--text-dark);
  font-size: 0.95rem;
}
.events-checkboxes input[type='checkbox'] {
  accent-color: var(--purple);
  width: 18px;
  height: 18px;
  margin: 0;
}

.sponsor-line {
  margin-top: 0.2rem;
  font-size: 0.9rem;
  color: var(--blue);
  font-weight: 600;
}

.team-section {
  background-color: var(--dark-blue);
  border-top: 1px solid var(--gray);
  padding: 3rem 0;
  text-align: center;
}
.team-section h2 {
  margin-top: 0;
  margin-bottom: 2rem;
  color: var(--light-pink);
}
.team-members {
  display: flex;
  justify-content: center;
  gap: 3rem;
  flex-wrap: wrap;
}
.team-member {
  max-width: 250px;
  text-align: center;
  color: var(--text-dark);
}
.team-photo {
  width: 140px;
  height: 140px;
  object-fit: cover;
  border-radius: 50%;
  border: 3px solid var(--purple);
  margin: 0 auto 0.8rem;
}
.team-member h3 {
  margin: 0;
  font-size: clamp(1.1rem, 2.3vw, 1.4rem);
  color: var(--white);
}
.team-member p {
  font-size: 0.95rem;
  color: var(--text-muted);
}
.team-name {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.6rem;
  margin: 0.5rem 0;
}
.team-name .social-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  background-color: var(--gray);
  transition: background-color 0.3s ease, transform 0.3s ease;
}
.team-name .social-icon:hover {
  background-color: var(--purple);
  transform: translateY(-2px);
}
.team-name .social-icon svg {
  width: 18px;
  height: 18px;
  fill: var(--white);
}

.hybrid-banner {
  background-color: var(--gray-light);
  border-top: 1px solid var(--gray);
  border-bottom: 1px solid var(--gray);
  padding: 2rem 0;
  position: relative;
  overflow: hidden;
}
.hybrid-banner p {
  margin: 0;
  font-size: clamp(1rem, 1.8vw, 1.15rem);
  line-height: 1.6;
  text-align: left;
  color: var(--text-muted);
}
.hybrid-banner strong {
  color: var(--light-pink);
}

.hybrid-banner::before,
.hybrid-banner::after {
  content: "";
  position: absolute;
  width: clamp(220px, 28vw, 360px);
  height: clamp(220px, 28vw, 360px);
  border-radius: 50%;
  filter: blur(18px);
  opacity: 0.45;
  pointer-events: none;
  transform: translate3d(0, 0, 0);
}

.hybrid-banner::before {
  left: clamp(-140px, -10vw, -80px);
  bottom: clamp(-160px, -8vw, -40px);
  background: radial-gradient(circle, rgba(126, 91, 255, 0.55), rgba(22, 34, 96, 0));
}

.hybrid-banner::after {
  right: clamp(-120px, -6vw, -20px);
  top: clamp(-140px, -12vw, -40px);
  background: radial-gradient(circle, rgba(255, 141, 255, 0.5), rgba(14, 24, 78, 0));
}

.hybrid-container {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 0.5rem;
}

.hybrid-header {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.hybrid-header h3 {
  margin: 0;
  color: var(--light-pink);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
}

.hybrid-cat {
  height: 48px;
  width: 48px;
  border-radius: 50%;
  object-fit: cover;
}

.hybrid-visuals {
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: clamp(1.75rem, 4vw, 3.25rem);
  width: 100%;
}

.hybrid-description {
  width: 100%;
}

.hybrid-description p {
  font-size: clamp(0.98rem, 1.7vw, 1.18rem);
  line-height: 1.75;
  margin: 0;
}

.hybrid-image-stack {
  position: relative;
  display: flex;
  flex-direction: row;
  justify-content: flex-start;
  align-items: center;
  gap: clamp(1.5rem, 3vw, 3rem);
  padding: clamp(1.75rem, 4vw, 3rem);
  border-radius: 26px;
  background: linear-gradient(160deg, rgba(94, 64, 196, 0.28), rgba(20, 32, 84, 0.85));
  box-shadow: 0 24px 50px rgba(12, 20, 48, 0.38);
  overflow: hidden;
  width: min(100%, 660px);
  align-self: center;
}

.hybrid-image-stack::after {
  content: "";
  position: absolute;
  inset: 16%;
  border-radius: 50%;
  background: radial-gradient(circle at 70% 30%, rgba(255, 141, 255, 0.35), transparent 60%),
    radial-gradient(circle at 30% 80%, rgba(85, 236, 255, 0.25), transparent 65%);
  filter: blur(4px);
  opacity: 0.7;
  pointer-events: none;
}

.hybrid-visual {
  position: relative;
  flex: 1 1 clamp(200px, 26vw, 280px);
  width: clamp(200px, 26vw, 280px);
  max-width: 100%;
  border-radius: 18px;
  box-shadow: 0 16px 30px rgba(10, 15, 40, 0.45);
}

@media (max-width: 960px) {
  .hybrid-visuals {
    align-items: center;
    text-align: center;
  }

  .hybrid-description {
    text-align: left;
  }

  .hybrid-image-stack {
    justify-content: center;
  }
}

@media (max-width: 640px) {
  .hybrid-visuals {
    align-items: stretch;
  }

  .hybrid-image-stack {
    flex-direction: column;
    gap: 1.5rem;
  }

  .hybrid-visual {
    width: min(100%, 220px);
  }
}

.intro-section {
  background-color: var(--dark-blue);
  text-align: center;
  padding: 2rem 0;
  border-top: 1px solid var(--gray);
}
.intro-section .intro-tagline {
  font-size: clamp(1.1rem, 2vw, 1.35rem);
  color: var(--text-muted);
  margin: 0 0 0.5rem;
}
.intro-section .intro-dates {
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  color: var(--light-pink);
  margin: 0;
}

.london-graphic {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 40%;
  max-width: 350px;
  opacity: 0.05;
  pointer-events: none;
}
.london-graphic img {
  width: 100%;
  height: auto;
}

.registration-section {
  background-color: var(--dark-blue);
  border-top: 1px solid var(--gray);
}
.registration-section h2 {
  color: var(--white);
  margin-top: 0;
  margin-bottom: 0.75rem;
}
.registration-intro {
  margin: 0 auto 2rem;
  max-width: 680px;
  display: flex;
  flex-direction: column;
  gap: 1.1rem;
}

.registration-lede {
  margin: 0;
  font-size: clamp(1rem, 1.6vw, 1.1rem);
  line-height: 1.7;
  color: var(--text-muted);
}

.registration-highlight {
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 0.85rem;
  padding: 0.85rem 1.15rem;
  border-radius: 12px;
  background: rgba(95, 121, 255, 0.18);
  border: 1px solid rgba(116, 152, 255, 0.25);
  box-shadow: 0 14px 36px rgba(20, 32, 84, 0.28);
  backdrop-filter: blur(10px);
}

.registration-highlight p {
  margin: 0;
  color: var(--white);
  font-weight: 600;
  letter-spacing: 0.01em;
}

.registration-icon {
  font-size: 1.25rem;
  line-height: 1;
  filter: drop-shadow(0 4px 8px rgba(12, 20, 48, 0.4));
}

.registration-note {
  margin: 0;
  text-align: center;
  color: var(--white);
  font-size: clamp(0.92rem, 1.4vw, 1rem);
  line-height: 1.6;
  opacity: 0.85;
}
.registration-form {
  max-width: 600px;
  margin: 0 auto;
  padding: 1.5rem;
  background-color: var(--gray-light);
  border-radius: 8px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.4);
}
.form-group {
  margin-bottom: 1rem;
}
.form-group label {
  display: block;
  margin-bottom: 0.3rem;
  font-weight: 600;
  font-size: 0.95rem;
}

.form-group .required {
  color: var(--pink);
  font-size: 0.85em;
  font-weight: 600;
  margin-left: 0.25rem;
}
.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.6rem;
  border: 1px solid var(--gray);
  border-radius: 4px;
  font-size: 1rem;
  background-color: var(--dark-blue);
  color: var(--text-dark);
  caret-color: var(--pink);
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--purple);
  box-shadow: 0 0 0 3px rgba(156, 90, 217, 0.4);
}
.captcha-group {
  display: block;
}
.captcha-group .g-recaptcha {
  margin: 0;
}

.select-help {
  display: block;
  margin-top: 0.25rem;
  font-size: 0.8rem;
  color: var(--text-muted);
}
.form-message {
  margin-top: 1rem;
  font-size: 0.9rem;
  color: var(--white);
}

.site-footer {
  position: relative;
  background-color: var(--dark-blue);
  border-top: 1px solid var(--gray);
  color: var(--white);
  padding: 2rem 0 3.5rem;
  text-align: center;
  overflow: hidden;
}
.footer-content {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 1rem;
}
.footer-logos {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.footer-badge {
  height: 85px;
  width: auto;
}
.footer-kcl-logo {
  height: 70px;
  width: auto;
}
.site-footer p {
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.6;
}

.footer-silhouette {
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100vw;
  max-width: none;
  min-width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.22;
  filter: invert(1);
  pointer-events: none;
  z-index: 0;
}

@media (max-width: 900px) {
  .hero {
    padding: 4.5rem 0 6rem;
  }
  .hero-content {
    text-align: center;
  }
}

@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }
  .nav-brand {
    gap: 0.4rem;
  }
  .qiskit-logo {
    height: 72px;
  }
  .kcl-logo {
    height: 68px;
  }
  .nav-links {
    position: absolute;
    top: calc(100% + 0.5rem);
    right: 0;
    flex-direction: column;
    width: min(220px, 80vw);
    padding: 0.75rem 0;
    background-color: rgba(14, 18, 38, 0.98);
    border: 1px solid var(--gray);
    border-radius: 10px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transform: translateY(-10px);
    transition: max-height 0.3s ease, opacity 0.3s ease, transform 0.3s ease;
    backdrop-filter: blur(12px);
    pointer-events: none;
  }
  .nav-links.nav-open {
    max-height: 320px;
    opacity: 1;
    transform: translateY(0);
    pointer-events: auto;
  }
  .nav-links li {
    margin: 0;
  }
  .nav-links li a {
    display: block;
    padding: 0.75rem 1.2rem;
    color: var(--text-dark);
  }
  .nav-links li a:hover {
    background-color: rgba(255, 255, 255, 0.08);
  }
  .hero {
    padding: 4rem 0 5rem;
  }
  .hero-content {
    text-align: center;
    padding: 0 1rem;
  }
  .hero h1 {
    font-size: clamp(2rem, 9vw, 3.1rem);
  }
  .hero p {
    font-size: 1rem;
  }
  .hero-silhouette img {
    transform: translateY(-4%) scale(1.15);
    opacity: 0.26;
  }
  .about-content {
    flex-direction: column;
    text-align: left;
  }
  .timeline {
    padding-left: 24px;
  }
  .timeline::after {
    left: 24px;
  }
}

@media (max-width: 640px) {
  .promo-banner {
    position: static;
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1rem;
  }
  .promo-tag-image {
    margin-left: 0;
    height: 28px;
  }
  .promo-text {
    font-size: 0.95rem;
  }
  .hero {
    padding: 0 0 3.75rem;
  }
  .hero-content {
    margin-top: 0.75rem;
  }
}

@media (max-width: 540px) {
  .hero {
    padding: 0 0 3.25rem;
  }
  .hero-content {
    padding: 0 0.75rem;
  }
  .qiskit-logo {
    height: 60px;
  }
  .kcl-logo {
    height: 56px;
  }
  .hero h1 {
    font-size: clamp(1.85rem, 10vw, 2.7rem);
  }
  .hero p {
    font-size: 0.95rem;
  }
  .hero-silhouette img {
    transform: translateY(-8%) scale(1.22);
    opacity: 0.24;
  }
  .intro-section .intro-tagline {
    font-size: 1rem;
  }
  .intro-section .intro-dates {
    font-size: 0.95rem;
  }
  .timeline-columns {
    gap: 1.5rem;
  }
  .timeline {
    padding-left: 18px;
  }
  .timeline::after {
    left: 18px;
  }
  .timeline-item {
    margin-bottom: 1.75rem;
    padding-left: 1rem;
  }
  .timeline-icon {
    left: -32px;
    width: 68px;
    height: 68px;
  }
  .timeline-icon img {
    width: 44px;
    height: 44px;
  }
  .timeline-content {
    margin-left: 1.5rem;
  }
  .registration-form {
    padding: 1.2rem;
  }
  .team-members {
    gap: 2rem;
  }
  .team-member p {
    font-size: 0.9rem;
  }
  .supported-logos {
    gap: 1.5rem;
  }
}