/* ============================================================
   Cyber-AI 2026 — global design tokens & base styles
   ============================================================ */
:root {
  --color-navy: #1a2a5e;
  --color-navy-dark: #111d45;
  --color-orange: #f47920;
  --color-orange-light: #fef3e8;
  --color-white: #ffffff;
  --color-grey-50: #f8f9fa;
  --color-grey-100: #f0f1f3;
  --color-grey-300: #ced4da;
  --color-grey-600: #6c757d;
  --color-grey-900: #212529;
  --color-success: #2d8a4e;
  --color-teal: #0d9488;
  --color-teal-light: color-mix(in srgb, #0d9488 12%, white);
  --color-muted: #9ca3af;
  --color-black: #000000;
  --hero-overlay: color-mix(in srgb, var(--color-navy) 72%, transparent);
  --shadow-nav-scroll: color-mix(in srgb, var(--color-black) 15%, transparent) 0
    var(--space-xs) var(--space-lg);
  --font-display: "Playfair Display", Georgia, serif;
  --font-body: "Source Sans 3", system-ui, sans-serif;
  --font-mono: "IBM Plex Mono", ui-monospace, monospace;
  --space-xs: 4px;
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 40px;
  --space-2xl: 64px;
  --space-3xl: 96px;
  --section-padding-desktop: 96px;
  --section-padding-mobile: 48px;
  --content-max-width: 1200px;
  --content-reading-width: 72ch;
  --nav-height-desktop: 80px;
  --nav-height-mobile: 56px;
  --nav-link-gap: var(--space-lg);
  --z-nav: 1000;
  --radius-button: var(--space-xs);
  --radius-logo-card: var(--space-sm);
  --radius-panel: var(--radius-logo-card);
  --font-size-body: 17px;
  --line-height-body: 1.75;
  --font-size-body-mobile: 16px;
  --line-height-body-mobile: 1.7;
  --font-size-nav-link: 14px;
  --font-size-nav-compact: 13px;
  --nav-link-gap-row: calc(var(--space-md) + var(--space-xs));
  --nav-link-gap-row-tight: var(--space-md);
  --font-size-small: 13px;
  --font-size-hero-title: 42px;
  --font-size-hero-meta: 16px;
  --font-size-hero-tagline: 13px;
  --size-logo-hero: 140px;
  --size-logo-card-height: 80px;
  --size-focus-ring: 2px;
  --size-divider-width: 48px;
  --size-divider-height: 3px;
  --size-nav-border-active: 2px;
  --media-tablet-max: 1023px;
  --media-mobile-max: 767px;
  --tap-min: 44px;
  --transition-accordion: 0.35s ease;
  --countdown-digit-size: clamp(1.5rem, 4vw, 2.25rem);
  --border-width-default: 1px;
  --font-size-partners-label: 12px;
  --letter-spacing-partners-label: 0.12em;
  --font-size-city-caption-label: 11px;
  --letter-spacing-city-caption-label: 0.14em;
  --font-size-city-caption-text: 22px;
  --size-partners-card-height: 100px;
  --size-partners-card-min-width: 180px;
  --size-partners-logo-max-height: 60px;
  --size-partners-logo-max-width: 160px;
  --size-partners-card-height-mobile: 80px;
  --size-partners-card-min-width-mobile: 140px;
  --size-city-banner-height: 420px;
  --size-city-banner-item-mobile: 260px;
  --transition-city-banner-zoom: 0.4s ease;
  --size-collaborators-card-min-width: 280px;
  --size-collaborators-logo-max-width: 260px;
  --shadow-collaborators-hover: 0 var(--space-xs) var(--space-lg)
    color-mix(in srgb, var(--color-navy) 12%, transparent);
  --size-guideline-border-left: 3px;
  --color-guideline-warning: #c0392b;
  --shadow-guideline-block: 0 var(--border-width-default) var(--space-xs)
    color-mix(in srgb, var(--color-black) 6%, transparent);
  --font-size-guideline-title: 20px;
  --font-weight-guideline-title: 600;
  --underline-offset-guideline-link: 3px;
  --line-height-guideline-li: 1.7;
}

/* === RESET & BASE === */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-grey-900);
  background: var(--color-white);
  padding-top: 80px;
}

main {
  display: block;
}

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

a {
  color: var(--color-navy);
}

a:focus-visible,
button:focus-visible {
  outline: var(--size-focus-ring) solid var(--color-orange);
  outline-offset: var(--space-xs);
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

/* === UTILITIES === */
.section__inner {
  width: 100%;
  max-width: var(--content-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--space-lg);
  padding-right: var(--space-lg);
}

.text-reading {
  max-width: var(--content-reading-width);
}

.content-block > .text-reading {
  margin-left: auto;
  margin-right: auto;
}

.link-back-top {
  display: flex;
  justify-content: center;
  align-items: center;
  margin-top: var(--space-xl);
  font-family: var(--font-body);
  font-weight: var(--fw-semibold);
  font-size: var(--font-size-small);
  color: var(--color-grey-600);
}

.link-back-top:hover {
  color: var(--color-orange);
}

.fw-semibold {
  font-weight: 600;
}

.u-mt-xl {
  margin-top: var(--space-xl);
}

/* === TYPOGRAPHY === */
:root {
  --fw-semibold: 600;
}

h1,
h2,
.section__title {
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-navy);
  margin: 0 0 var(--space-md);
}

/* === NAVIGATION === */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-nav);
  height: var(--nav-height-desktop);
  background: var(--color-navy);
  color: var(--color-white);
  transition: box-shadow var(--transition-accordion);
}

.nav.scrolled {
  box-shadow: var(--shadow-nav-scroll);
}

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

.nav__brand {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-white);
  text-decoration: none;
  white-space: nowrap;
  flex-shrink: 0;
  min-height: var(--tap-min);
  display: inline-flex;
  align-items: center;
}

.nav__brand:hover {
  color: var(--color-orange-light);
}

.nav__toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: var(--tap-min);
  height: var(--tap-min);
  padding: 0;
  border: none;
  background: transparent;
  color: var(--color-white);
  font-size: calc(var(--space-lg) * 1);
  cursor: pointer;
}

.nav__links {
  display: flex;
  flex-direction: row;
  flex-wrap: nowrap;
  align-items: center;
  justify-content: center;
  gap: var(--nav-link-gap);
  list-style: none;
  margin: 0;
  padding: 0;
}

.nav__link {
  font-size: 15px;
  font-weight: var(--fw-semibold);
  letter-spacing: 0.02em;
  color: var(--color-white);
  text-decoration: none;
  padding: var(--space-sm) 0;
  border-bottom: var(--size-nav-border-active) solid transparent;
  min-height: var(--tap-min);
  display: inline-flex;
  align-items: center;
  white-space: nowrap;
}

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

.nav__link.is-active {
  border-bottom-color: var(--color-orange);
}

.nav__cta {
  font-size: 15px;
  font-weight: var(--fw-semibold);
  background: var(--color-orange);
  color: var(--color-white);
  text-decoration: none;
  padding: 10px var(--space-lg);
  border-radius: var(--radius-button);
  white-space: nowrap;
  min-height: var(--tap-min);
  display: inline-flex;
  align-items: center;
  justify-content: center;
}

.nav__cta:hover {
  filter: brightness(1.05);
}

.nav__panel {
  display: flex;
  flex: 1;
  align-items: center;
  justify-content: center;
  gap: var(--space-lg);
}

/* === NAV DROPDOWN === */
.nav__dropdown {
  position: relative;
}

.nav__dropdown-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  cursor: pointer;
  user-select: none;
  background: none;
  border: none;
  font: inherit;
  letter-spacing: inherit;
  text-align: left;
}

.nav__dropdown-arrow {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 10px;
  height: 10px;
  flex-shrink: 0;
}

.nav__dropdown-arrow svg {
  width: 10px;
  height: 10px;
  fill: none;
  stroke: color-mix(in srgb, var(--color-white) 70%, transparent);
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  transition: transform 0.2s ease;
}

.nav__dropdown.is-open .nav__dropdown-arrow svg {
  transform: rotate(180deg);
}

.nav__dropdown::after {
  content: "";
  display: none;
  position: absolute;
  top: 100%;
  left: 0;
  right: 0;
  height: 12px;
}

.nav__dropdown.is-open::after {
  display: block;
}

.nav__dropdown-menu {
  display: none;
  position: absolute;
  top: calc(100% + 4px);
  left: 0;
  min-width: 220px;
  background: var(--color-navy-dark);
  border: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
  border-radius: var(--radius-panel);
  padding: var(--space-sm) 0;
  z-index: 200;
  box-shadow: 0 18px 44px color-mix(in srgb, var(--color-black) 32%, transparent);
}

.nav__dropdown.is-open .nav__dropdown-menu {
  display: block;
}

.nav__dropdown-menu a {
  display: block;
  padding: 10px var(--space-lg);
  font-family: var(--font-body);
  font-size: var(--font-size-small);
  font-weight: var(--fw-semibold);
  color: color-mix(in srgb, var(--color-white) 78%, transparent);
  text-decoration: none;
  transition: background 0.15s ease, color 0.15s ease;
}

.nav__dropdown-menu a:hover {
  background: color-mix(in srgb, var(--color-white) 6%, transparent);
  color: var(--color-orange-light);
}

.nav__dropdown-menu a.is-active {
  color: var(--color-orange);
}

/* === HERO === */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: flex-start;
  padding: var(--space-xl) var(--space-lg) var(--space-xl);
  text-align: center;
  color: var(--color-white);
  background-color: var(--color-navy);
  /* Triumph Arch hero (resolved from stylesheet: assets/images/r3new.webp) */
  background-image: url("../images/r3new.webp");
  background-repeat: no-repeat;
  background-size: cover;
  background-position: center;
}

.hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--hero-overlay);
}

.hero__content {
  position: relative;
  z-index: 1;
  max-width: var(--content-max-width);
}

.hero__badge {
  width: var(--size-logo-hero);
  height: var(--size-logo-hero);
  border-radius: 50%;
  object-fit: contain;
  margin-bottom: var(--space-md);
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--font-size-hero-title);
  font-weight: 700;
  line-height: 1.2;
  color: var(--color-white);
  margin: 0 0 var(--space-md);
}

.hero__meta {
  font-family: var(--font-mono);
  font-size: var(--font-size-hero-meta);
  color: var(--color-orange);
  margin: 0 0 var(--space-sm);
}

.hero__tagline {
  font-family: var(--font-body);
  font-size: var(--font-size-hero-tagline);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--color-white);
  margin: 0 0 var(--space-lg);
}

.hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
  margin-bottom: var(--space-xl);
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: var(--tap-min);
  padding: var(--space-sm) var(--space-lg);
  font-family: var(--font-body);
  font-size: var(--font-size-nav-link);
  font-weight: var(--fw-semibold);
  text-decoration: none;
  border-radius: var(--radius-button);
  cursor: pointer;
  border: var(--size-nav-border-active) solid transparent;
}

.btn--primary {
  background: var(--color-orange);
  color: var(--color-white);
  border-color: var(--color-orange);
}

.btn--primary:hover {
  filter: brightness(1.05);
}

.btn--outline {
  background: transparent;
  color: var(--color-white);
  border-color: var(--color-white);
}

.btn--outline:hover {
  background: color-mix(in srgb, var(--color-white) 12%, transparent);
}

.btn--secondary {
  background: transparent;
  color: var(--color-navy);
  border-color: var(--color-navy);
}

.btn--secondary:hover {
  background: color-mix(in srgb, var(--color-navy) 8%, transparent);
}

/* === HERO DATE STRIP === */
.hero-dates {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: var(--content-max-width);
  margin: 0 auto var(--space-xl);
}

.hero-dates__track {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
  background: color-mix(in srgb, var(--color-navy-dark) 60%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-white) 15%, transparent);
  border-radius: var(--radius-panel);
  padding: var(--space-md) var(--space-lg);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
}

.hero-dates__group {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: var(--space-sm);
  flex: 1;
  min-width: 0;
}

.hero-dates__group-label {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-orange);
  font-weight: 500;
  padding-bottom: var(--space-xs);
  border-bottom: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
  width: 100%;
}

.hero-dates__pills {
  display: flex;
  flex-direction: row;
  flex-wrap: wrap;
  gap: var(--space-sm);
  width: 100%;
}

.hero-dates__pill {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 2px;
  background: color-mix(in srgb, var(--color-white) 7%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
  border-radius: var(--radius-button);
  padding: var(--space-sm) var(--space-md);
  min-width: 110px;
  transition: background 0.2s ease, border-color 0.2s ease;
}

.hero-dates__pill:hover {
  background: color-mix(in srgb, var(--color-white) 12%, transparent);
  border-color: color-mix(in srgb, var(--color-white) 22%, transparent);
}

.hero-dates__pill .hero-dates__pill-name {
  font-size: 11px;
  font-weight: 600;
  color: color-mix(in srgb, var(--color-white) 85%, transparent);
  text-decoration: none;
  line-height: 1.3;
}

.hero-dates__pill .hero-dates__pill-date {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  color: var(--color-white);
}

.hero-dates__pill .dates-card__badge {
  font-size: 10px;
  padding: 1px var(--space-xs);
  margin-top: 2px;
}

.hero-dates__pill .dates-card__badge--closed {
  background: color-mix(in srgb, var(--color-white) 12%, transparent);
  color: color-mix(in srgb, var(--color-white) 55%, transparent);
}

.hero-dates__pill .dates-card__badge--open {
  background: color-mix(in srgb, var(--color-success) 25%, transparent);
  color: color-mix(in srgb, var(--color-success) 80%, var(--color-white));
}

.hero-dates__pill .dates-card__badge--extended,
.hero-dates__pill .dates-card__badge--soon {
  background: color-mix(in srgb, var(--color-orange) 25%, transparent);
  color: var(--color-orange-light);
}

.hero-dates__pill.is-past .hero-dates__pill-name {
  color: color-mix(in srgb, var(--color-white) 35%, transparent);
}

.hero-dates__pill.is-past .hero-dates__pill-date {
  color: color-mix(in srgb, var(--color-white) 35%, transparent);
}

.hero-dates__divider {
  width: 1px;
  align-self: stretch;
  background: color-mix(in srgb, var(--color-white) 15%, transparent);
  flex-shrink: 0;
}

.hero-dates__more {
  display: block;
  text-align: center;
  margin-top: var(--space-sm);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: color-mix(in srgb, var(--color-white) 55%, transparent);
  text-decoration: none;
  transition: color 0.2s ease;
}

.hero-dates__more:hover {
  color: var(--color-orange-light);
}

@media screen and (max-width: 767px) {
  .hero-dates__track {
    flex-direction: column;
    gap: var(--space-md);
  }

  .hero-dates__divider {
    display: none;
  }

  .hero-dates__group {
    width: 100%;
  }

  .hero-dates__pills {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .hero-dates__pill {
    min-width: calc(50% - var(--space-xs));
    flex: 1;
  }
}

/* === COUNTDOWN === */
.countdown {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-md);
}

.countdown__unit {
  min-width: calc(var(--tap-min) * 2);
  padding: var(--space-md);
  background: color-mix(in srgb, var(--color-navy-dark) 55%, transparent);
  border: 1px solid color-mix(in srgb, var(--color-white) 25%, transparent);
  border-radius: var(--radius-panel);
}

.countdown__value {
  font-family: var(--font-mono);
  font-size: var(--countdown-digit-size);
  font-weight: 500;
  color: var(--color-white);
  line-height: 1.2;
}

.countdown__label {
  font-family: var(--font-body);
  font-size: var(--font-size-small);
  color: var(--color-orange-light);
  margin-top: var(--space-xs);
}

/* === SECTIONS (shared) === */
.section {
  padding: var(--section-padding-desktop) 0;
  opacity: 0;
  transform: translateY(var(--space-md));
  transition:
    opacity 0.5s ease,
    transform 0.5s ease;
  scroll-margin-top: var(--nav-height-desktop);
}

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

.section--home {
  padding: 0;
  opacity: 1;
  transform: none;
}

.section--alt {
  background: var(--color-grey-50);
}

.section__header {
  text-align: center;
  max-width: var(--content-max-width);
  margin: 0 auto var(--space-xl);
}

.section__title {
  font-size: clamp(1.75rem, 3vw, 2.25rem);
}

.section__divider {
  width: var(--size-divider-width);
  height: var(--size-divider-height);
  background: var(--color-orange);
  margin: var(--space-md) auto;
  border: none;
}

.section__subtitle {
  font-family: var(--font-body);
  font-size: var(--font-size-body);
  color: var(--color-grey-600);
  margin: 0;
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
}

/* === WELCOME (homepage below hero) === */
.welcome {
  padding: var(--section-padding-desktop) 0;
  background: var(--color-white);
}

.welcome__container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  text-align: center;
}

.welcome__text {
  max-width: var(--content-reading-width);
  margin: 0 auto;
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-grey-900);
  text-align: left;
}

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

/* === WELCOME STATS === */
.welcome__stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  margin: var(--space-xl) auto var(--space-xl);
  padding: var(--space-lg) var(--space-xl);
  background: var(--color-grey-50);
  border: 1px solid var(--color-grey-100);
  border-radius: var(--radius-panel);
  max-width: var(--content-reading-width);
  flex-wrap: nowrap;
  overflow-x: auto;
}

.welcome__stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-xs);
  text-align: center;
  flex: 1;
  min-width: 0;
  padding: var(--space-md) var(--space-lg);
}

.welcome__stat-value {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3vw, 2.5rem);
  font-weight: 700;
  color: var(--color-navy);
  line-height: 1;
}

.welcome__stat-label {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-grey-600);
}

.welcome__stat-divider {
  width: 1px;
  height: 48px;
  background: var(--color-grey-300);
  flex-shrink: 0;
  align-self: center;
}

@media screen and (max-width: 767px) {
  .welcome__stats {
    gap: var(--space-lg);
    padding: var(--space-lg);
  }

  .welcome__stat-divider {
    display: none;
  }
}

/* === PARTNERS STRIP === */
.partners {
  background: var(--color-grey-50);
  padding: var(--space-2xl) 0;
  border-top: var(--border-width-default) solid var(--color-grey-100);
  border-bottom: var(--border-width-default) solid var(--color-grey-100);
}

.partners__container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  text-align: center;
}

.partners__label {
  font-family: var(--font-mono);
  font-size: var(--font-size-partners-label);
  letter-spacing: var(--letter-spacing-partners-label);
  text-transform: uppercase;
  color: var(--color-grey-600);
  margin: 0 0 var(--space-xl);
}

.partners__grid {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
}

.partners__card {
  background: var(--color-white);
  border: var(--border-width-default) solid var(--color-grey-300);
  border-radius: var(--radius-logo-card);
  padding: var(--space-lg) var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--size-partners-card-height);
  min-width: var(--size-partners-card-min-width);
}

.partners__logo {
  max-height: var(--size-partners-logo-max-height);
  max-width: var(--size-partners-logo-max-width);
  object-fit: contain;
  display: block;
}

/* === CITY & VENUE BANNER === */
.city-banner {
  width: 100%;
  overflow: hidden;
}

.city-banner__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  height: var(--size-city-banner-height);
}

.city-banner__item {
  position: relative;
  overflow: hidden;
}

.city-banner__image {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  display: block;
  transition: transform var(--transition-city-banner-zoom);
}

.city-banner__item:hover .city-banner__image {
  transform: scale(1.03);
}

.city-banner__caption {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(
    to top,
    color-mix(in srgb, var(--color-navy) 85%, transparent),
    transparent
  );
  padding: var(--space-xl) var(--space-lg) var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.city-banner__caption-label {
  font-family: var(--font-mono);
  font-size: var(--font-size-city-caption-label);
  letter-spacing: var(--letter-spacing-city-caption-label);
  text-transform: uppercase;
  color: var(--color-orange);
}

.city-banner__caption-text {
  font-family: var(--font-display);
  font-size: var(--font-size-city-caption-text);
  color: var(--color-white);
  font-weight: 600;
}

/* === INSTITUTIONAL COLLABORATORS (homepage) === */
.collaborators {
  background: var(--color-white);
  padding: var(--section-padding-desktop) 0;
}

.collaborators__container {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-xl);
  text-align: center;
}

.collaborators__grid {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-xl);
  flex-wrap: wrap;
  margin-top: var(--space-xl);
}

.collaborators__card {
  background: var(--color-white);
  border: var(--border-width-default) solid var(--color-grey-300);
  border-radius: var(--radius-logo-card);
  padding: var(--space-lg) var(--space-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--size-partners-card-height);
  min-width: var(--size-collaborators-card-min-width);
  text-decoration: none;
  transition:
    box-shadow var(--transition-accordion),
    border-color var(--transition-accordion);
}

.collaborators__card:hover {
  box-shadow: var(--shadow-collaborators-hover);
  border-color: var(--color-navy);
}

.collaborators__logo {
  max-height: var(--size-partners-logo-max-height);
  max-width: var(--size-collaborators-logo-max-width);
  object-fit: contain;
  display: block;
}

.section-footer-cta {
  margin-top: var(--space-xl);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  align-items: center;
  justify-content: center;
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
}

/* === CALL FOR PAPERS & CONTENT === */
.content-block {
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.content-block p,
.content-block li {
  max-width: var(--content-reading-width);
}

.content-block ul.topics {
  max-width: none;
  columns: 1;
}

.topics__grid {
  display: flex;
  flex-direction: column;
  gap: 0;
  margin: var(--space-xl) auto;
  max-width: var(--content-reading-width);
  background: var(--color-white);
  border-radius: 8px;
  border: 1px solid var(--color-grey-300);
  box-shadow: 0 2px 12px color-mix(in srgb, var(--color-navy) 6%, transparent);
  overflow: hidden;
}

.topics__item {
  font-size: 14px;
  line-height: 1.5;
  color: var(--color-grey-900);
  padding: 10px var(--space-lg);
  border-left: 3px solid var(--color-orange);
  border-bottom: 1px solid var(--color-grey-100);
  transition: background 0.2s ease;
}

.topics__item:nth-child(even) {
  background: var(--color-grey-50);
}

.topics__item:last-child {
  border-bottom: none;
}

.topics__item:hover {
  background: color-mix(in srgb, var(--color-orange) 5%, transparent);
}

.topic-list {
  margin: var(--space-md) 0;
  padding-left: var(--space-xl);
}

.topic-list li {
  margin-bottom: var(--space-sm);
  max-width: none;
}

.submission-system {
  text-align: center;
  padding: var(--space-xl) var(--space-2xl);
  background: var(--color-navy);
  border-radius: 8px;
  margin: var(--space-xl) auto;
  max-width: var(--content-reading-width);
}

.submission-system__title {
  font-family: var(--font-display);
  font-size: 22px;
  color: var(--color-white);
  margin: 0 0 var(--space-sm);
}

.submission-system__text {
  font-size: 15px;
  color: color-mix(in srgb, var(--color-white) 70%, transparent);
  margin: 0 0 var(--space-lg);
}

.submission-system__btn {
  display: inline-block;
  background: var(--color-orange);
  color: var(--color-white);
  padding: var(--space-md) var(--space-xl);
  border-radius: 4px;
  text-decoration: none;
  font-weight: 600;
  font-size: 15px;
  transition: background 0.2s ease;
}

.submission-system__btn:hover {
  filter: brightness(1.1);
  background: var(--color-orange);
  border-color: var(--color-orange);
}

.workshop-proposals {
  margin-top: var(--space-2xl);
  padding-top: var(--space-2xl);
  border-top: 1px solid var(--color-grey-100);
}

.workshop-proposals__intro {
  font-size: 17px;
  line-height: 1.75;
  color: var(--color-grey-900);
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
  margin-bottom: var(--space-xl);
}

#calls .guideline__body ul ul,
#workshops .guideline__body ul ul {
  margin-top: var(--space-sm);
  padding-left: var(--space-lg);
  list-style-type: circle;
}

#calls .guideline__body ul ul li,
#workshops .guideline__body ul ul li {
  font-size: 15px;
  color: var(--color-grey-600);
}

.lead {
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
}

/* === COMMITTEE === */
.committee-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-xl);
}

.committee-block h3 {
  font-family: var(--font-display);
  color: var(--color-navy);
  margin: 0 0 var(--space-md);
  font-size: calc(var(--font-size-hero-meta) + var(--space-xs));
}

.committee-block ul {
  margin: 0;
  padding-left: var(--space-lg);
  color: var(--color-grey-900);
}

.committee-block li {
  margin-bottom: var(--space-sm);
}

/* === SPEAKERS & EMPTY STATES === */
.empty-state {
  text-align: center;
  padding: var(--space-2xl) var(--space-lg);
  background: var(--color-grey-50);
  border: 1px solid var(--color-grey-300);
  border-radius: var(--radius-panel);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.empty-state__icon {
  font-size: calc(var(--space-2xl) + var(--space-md));
  line-height: 1;
  margin-bottom: var(--space-md);
  color: var(--color-grey-600);
}

.empty-state p {
  margin: 0 auto;
  color: var(--color-grey-600);
  max-width: var(--content-reading-width);
}

.content-heading {
  font-family: var(--font-display);
  font-size: calc(var(--font-size-hero-meta) + var(--space-xs));
  color: var(--color-navy);
  margin: var(--space-xl) 0 var(--space-md);
}

/* === SPONSORS === */
.sponsors-groups {
  display: flex;
  flex-direction: column;
  gap: var(--space-xl);
}

.sponsors-subtitle {
  font-family: var(--font-display);
  font-size: calc(var(--font-size-hero-meta) + var(--space-xs));
  color: var(--color-navy);
  margin: 0 0 var(--space-lg);
  text-align: center;
}

.logo-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: var(--space-lg);
}

.logo-card {
  display: flex;
  align-items: center;
  justify-content: center;
  height: var(--size-logo-card-height);
  padding: var(--space-md) var(--space-lg);
  background: var(--color-white);
  border: 1px solid var(--color-grey-300);
  border-radius: var(--radius-logo-card);
}

.logo-card a {
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100%;
}

.logo-card img {
  max-height: 100%;
  width: auto;
  object-fit: contain;
}

/* === AUTHORS GUIDELINES (static #authors only) === */
.guidelines__wrapper {
  max-width: var(--content-reading-width);
  margin: var(--space-2xl) auto 0;
  width: 100%;
}

.guidelines__wrapper.u-mt-xl {
  margin-left: auto;
  margin-right: auto;
}

.guideline__block {
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
  border-left: var(--size-guideline-border-left) solid var(--color-orange);
  padding: var(--space-lg) var(--space-xl);
  margin-bottom: 0;
  background: var(--color-white);
  border-radius: 0;
  border-bottom: 1px solid var(--color-grey-100);
  box-shadow: var(--shadow-guideline-block);
}

.guideline__block:last-child {
  border-bottom: none;
}

.guideline__header {
  margin-bottom: var(--space-md);
}

.guideline__title {
  font-family: var(--font-display);
  font-size: var(--font-size-guideline-title);
  font-weight: var(--font-weight-guideline-title);
  color: var(--color-navy);
  margin: 0;
}

.guideline__body {
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
  color: var(--color-grey-900);
}

.guideline__body p {
  margin-bottom: var(--space-md);
  font-size: var(--font-size-body);
}

.guideline__body p:last-child {
  margin-bottom: 0;
}

.guideline__body ul {
  padding-left: var(--space-lg);
  margin-bottom: var(--space-md);
}

.guideline__body li {
  margin-bottom: var(--space-sm);
  line-height: var(--line-height-guideline-li);
  font-size: var(--font-size-body);
}

.guideline__body a {
  color: var(--color-navy);
  text-decoration: underline;
  text-underline-offset: var(--underline-offset-guideline-link);
}

.guideline__body a:hover {
  color: var(--color-orange);
}

.guideline__warning {
  color: var(--color-guideline-warning);
  font-weight: var(--fw-semibold);
}

/* === ACCORDION === */
.accordion {
  max-width: var(--content-reading-width);
  margin: var(--space-lg) auto 0;
  border: 1px solid var(--color-grey-300);
  border-radius: var(--radius-panel);
  overflow: hidden;
}

.accordion__item + .accordion__item {
  border-top: 1px solid var(--color-grey-300);
}

.accordion__header {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-md);
  padding: var(--space-md) var(--space-lg);
  font-family: var(--font-display);
  font-size: calc(var(--font-size-nav-link) + var(--space-xs));
  text-align: left;
  background: var(--color-grey-50);
  color: var(--color-navy);
  border: none;
  cursor: pointer;
  min-height: var(--tap-min);
}

.accordion__header:hover {
  background: var(--color-grey-100);
}

.accordion__chevron {
  flex-shrink: 0;
  font-size: var(--font-size-hero-meta);
  line-height: 1;
  color: var(--color-orange);
}

.accordion__panel {
  overflow: hidden;
  transition: max-height var(--transition-accordion);
}

.accordion__panel-inner {
  padding: var(--space-md) var(--space-lg) var(--space-lg);
}

.accordion__panel-inner p,
.accordion__panel-inner li {
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
}

.accordion__panel-inner ul {
  padding-left: var(--space-lg);
}

.accordion__item.is-collapsed .accordion__panel {
  max-height: 0;
}

.accordion__item:not(.is-collapsed) .accordion__panel {
  max-height: var(--accordion-panel-max-open, 2400px);
}

.accordion__item.is-collapsed .accordion__panel-inner {
  padding-top: 0;
  padding-bottom: 0;
}

/* === REGISTRATION TABLE === */
.reg-wrap {
  overflow-x: auto;
  margin: var(--space-lg) 0;
  -webkit-overflow-scrolling: touch;
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
}

.reg-table {
  width: 100%;
  border-collapse: collapse;
  font-size: var(--font-size-nav-link);
  background: var(--color-white);
  border: 1px solid var(--color-grey-300);
}

.reg-table th,
.reg-table td {
  padding: var(--space-md);
  text-align: left;
  border-bottom: 1px solid var(--color-grey-300);
}

.reg-table thead th {
  background: var(--color-navy);
  color: var(--color-white);
  font-weight: var(--fw-semibold);
}

.reg-table tbody tr:nth-child(even) {
  background: var(--color-grey-50);
}

.reg-note {
  font-size: var(--font-size-small);
  color: var(--color-grey-600);
  margin-top: var(--space-md);
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
  text-align: left;
}

#registration .text-reading {
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
}

/* === VENUE === */
.venue-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-lg);
  align-items: start;
}

.venue-figure {
  margin: 0;
  background: var(--color-white);
  border: 1px solid var(--color-grey-300);
  border-radius: var(--radius-panel);
  overflow: hidden;
}

.venue-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.venue-figure figcaption {
  padding: var(--space-sm) var(--space-md);
  font-size: var(--font-size-small);
  color: var(--color-grey-600);
}

/* === WORKSHOPS PAGE BLOCKS === */
.workshops-block {
  max-width: var(--content-reading-width);
  margin: 0 auto var(--space-xl);
  font-size: var(--font-size-body);
  line-height: var(--line-height-body);
}

#workshops .guidelines__wrapper {
  max-width: var(--content-reading-width);
  margin-left: auto;
  margin-right: auto;
}

.workshops-block h3 {
  font-family: var(--font-display);
  color: var(--color-navy);
}

/* === FOOTER === */
.footer {
  background: var(--color-navy-dark);
  color: var(--color-white);
  padding: var(--space-2xl) 0 var(--space-md);
}

.footer a {
  color: var(--color-orange-light);
}

.footer a:hover {
  color: var(--color-white);
}

.footer__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: 0 var(--space-lg) var(--space-xl);
}

.footer__col h3 {
  font-family: var(--font-display);
  font-size: var(--font-size-hero-meta);
  margin: 0 0 var(--space-md);
  color: var(--color-white);
}

.footer__list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.footer__list li {
  margin-bottom: var(--space-sm);
}

.footer__list a {
  text-decoration: none;
  font-weight: var(--fw-semibold);
}

.footer__deadlines li {
  font-family: var(--font-mono);
  font-size: var(--font-size-small);
  color: var(--color-orange-light);
  margin-bottom: var(--space-sm);
}

.footer__bar {
  border-top: 1px solid color-mix(in srgb, var(--color-white) 15%, transparent);
  padding-top: var(--space-md);
  text-align: center;
  font-size: var(--font-size-small);
  color: var(--color-grey-600);
}

/* === TABLET === */
@media screen and (max-width: 1023px) {
  .committee-grid {
    grid-template-columns: 1fr;
  }

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

/* === MOBILE === */
@media screen and (max-width: 767px) {
  body {
    padding-top: var(--nav-height-mobile);
    font-size: var(--font-size-body-mobile);
    line-height: var(--line-height-body-mobile);
  }

  .nav {
    height: var(--nav-height-mobile);
  }

  .nav__toggle {
    display: inline-flex;
  }

  .nav__panel {
    display: none;
    position: absolute;
    top: var(--nav-height-mobile);
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--color-navy);
    padding: var(--space-md) var(--space-lg) var(--space-xl);
    box-shadow: var(--shadow-nav-scroll);
    max-height: calc(100vh - var(--nav-height-mobile));
    overflow-y: auto;
  }

  .nav.open .nav__panel {
    display: flex;
  }

  .nav__links {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }

  .nav__link {
    padding: var(--space-md) 0;
    border-bottom: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
  }

  .nav__cta {
    margin-top: var(--space-md);
    justify-content: center;
  }

  .nav__dropdown::after {
    display: none !important;
  }

  .nav__dropdown-menu {
    position: static;
    top: auto;
    left: auto;
    min-width: 0;
    margin-top: 0;
    padding: 0;
    background: transparent;
    border: none;
    border-radius: 0;
    box-shadow: none;
  }

  .nav__dropdown-menu a {
    padding: var(--space-md) var(--space-lg);
    border-bottom: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
    color: color-mix(in srgb, var(--color-white) 85%, transparent);
  }

  .nav__dropdown-toggle {
    width: 100%;
    justify-content: space-between;
    padding: var(--space-md) 0;
    border-bottom: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
  }

  .section {
    padding: var(--section-padding-mobile) 0;
    scroll-margin-top: var(--nav-height-mobile);
  }

  .welcome {
    padding: var(--section-padding-mobile) 0;
  }

  .collaborators {
    padding: var(--section-padding-mobile) 0;
  }

  .city-banner__grid {
    grid-template-columns: 1fr;
    height: auto;
  }

  .city-banner__item {
    height: var(--size-city-banner-item-mobile);
  }

  .partners__grid {
    gap: var(--space-md);
  }

  .partners__card {
    min-width: var(--size-partners-card-min-width-mobile);
    height: var(--size-partners-card-height-mobile);
  }

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

  .hero {
    width: 100%;
    margin-left: 0;
    margin-right: 0;
    padding-left: var(--space-md);
    padding-right: var(--space-md);
    min-height: auto;
    padding-top: var(--space-xl);
  }

  .section--home {
    padding: 0;
    margin: 0;
    overflow-x: hidden;
  }

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

/* === DESKTOP & TABLET NAVIGATION (≥768px, single row; hamburger only <768px) === */
@media screen and (min-width: 768px) {
  .nav__inner {
    position: relative;
  }

  .nav__toggle {
    display: none !important;
  }

  .nav__panel {
    display: contents;
  }

  .nav__links {
    flex: 1;
    flex-direction: row;
    flex-wrap: nowrap;
    justify-content: center;
    align-items: center;
    gap: var(--nav-link-gap-row-tight);
    position: static;
    transform: none;
    max-width: none;
    min-width: 0;
  }

  .nav__link {
    border-bottom-width: var(--size-nav-border-active);
    border-bottom-style: solid;
    border-bottom-color: transparent;
    padding: var(--space-sm) 0;
    font-size: var(--font-size-nav-compact);
  }

  .nav__cta {
    margin-top: 0;
    flex-shrink: 0;
    font-size: var(--font-size-nav-compact);
  }

  .nav__brand {
    flex-shrink: 0;
  }
}

/* === DESKTOP NAVIGATION (≥1024px: 20px link gap; tighten to 16px + 13px when needed) === */
@media screen and (min-width: 1024px) {
  .nav__links {
    gap: var(--nav-link-gap-row);
  }

  .nav__link,
  .nav__cta {
    font-size: var(--font-size-nav-link);
  }
}

@media screen and (min-width: 1024px) and (max-width: 1279px) {
  .nav__links {
    gap: var(--nav-link-gap-row-tight);
  }

  .nav__link,
  .nav__cta {
    font-size: var(--font-size-nav-compact);
  }
}

#camera-ready .guideline__block {
  border-left-color: var(--color-teal);
}

#camera-ready .guideline__title {
  color: var(--color-teal);
}

#camera-ready .section-footer-cta .btn--primary {
  background: var(--color-teal);
  border-color: var(--color-teal);
}

#camera-ready .section-footer-cta .btn--primary:hover {
  background: color-mix(in srgb, var(--color-teal) 85%, black);
  border-color: color-mix(in srgb, var(--color-teal) 85%, black);
}

#camera-ready .section__divider {
  background: var(--color-teal);
}