/* =============================================
   REUSABLE UI COMPONENTS
   TESOL Vietnam 2026
   ============================================= */

/* =============================================
   HEADER / NAVIGATION
   ============================================= */
#header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  transition: all var(--transition-base);
}

#header .nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

/* Transparent header on hero */
#header.transparent {
  background: transparent;
}

/* Scrolled header */
#header.scrolled {
  background: rgba(10, 15, 30, 0.92);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.2);
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  text-decoration: none;
}

.nav-logo__icon {
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, var(--color-accent), var(--color-accent-dark));
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: 0.65rem;
  letter-spacing: -0.03em;
  color: var(--color-white);
  flex-shrink: 0;
}

.nav-logo__text {
  display: flex;
  flex-direction: column;
  line-height: 1.2;
}

.nav-logo__title {
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--color-white);
  letter-spacing: 0.02em;
}

.nav-logo__sub {
  font-family: var(--font-body);
  font-weight: 400;
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.55);
  letter-spacing: 0.04em;
}

/* Nav links */
.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-link {
  position: relative;
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-white);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  letter-spacing: 0.01em;
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  width: 0;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
  transition: width var(--transition-base);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-white);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 20px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Hamburger */
.nav-hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-md);
  transition: background var(--transition-fast);
}

.nav-hamburger:hover {
  background: rgba(255, 255, 255, 0.1);
}

.nav-hamburger__bar {
  width: 24px;
  height: 2px;
  background: var(--color-white);
  border-radius: 2px;
  transition: all var(--transition-base);
}

.nav-hamburger.open .nav-hamburger__bar:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-hamburger.open .nav-hamburger__bar:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.nav-hamburger.open .nav-hamburger__bar:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Nav */
.nav-mobile {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  background: rgba(10, 15, 30, 0.97);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  padding: var(--space-6) var(--container-padding);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  flex-direction: column;
  gap: var(--space-2);
  z-index: 999;
  transform: translateY(-10px);
  opacity: 0;
  transition: all var(--transition-base);
}

.nav-mobile.open {
  transform: translateY(0);
  opacity: 1;
}

.nav-mobile__link {
  display: block;
  font-family: var(--font-heading);
  font-size: var(--text-base);
  font-weight: 500;
  color: rgba(255, 255, 255, 0.8);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
  border-bottom: 1px solid rgba(255, 255, 255, 0.04);
}

.nav-mobile__link:hover {
  color: var(--color-white);
  background: rgba(255, 255, 255, 0.06);
}

.nav-mobile__cta {
  margin-top: var(--space-4);
  width: 100%;
  justify-content: center;
}

@media (max-width: 1024px) {
  .nav-menu { display: none; }
  .nav-hamburger { display: flex; }
  .nav-actions .btn { display: none; }
  .nav-mobile { display: flex; }
}

/* =============================================
   SPEAKER CARDS
   ============================================= */
.speaker-card {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  transition: all var(--transition-slow);
  border: 1px solid var(--color-gray-100);
  cursor: pointer;
}

.speaker-card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-card-hover);
}

.speaker-card__image {
  position: relative;
  aspect-ratio: 4/5;
  overflow: hidden;
  background: linear-gradient(135deg, #1A3C6E 0%, #2A5298 100%);
}

.speaker-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.speaker-card:hover .speaker-card__image img {
  transform: scale(1.05);
}

.speaker-card__overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 60%;
  background: linear-gradient(to top, rgba(10, 15, 30, 0.85), transparent);
}

.speaker-card__avatar {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* Decorative circles in background */
.speaker-card__avatar::before {
  content: '';
  position: absolute;
  width: 200px;
  height: 200px;
  border-radius: 50%;
  border: 40px solid rgba(255, 255, 255, 0.04);
  bottom: -60px;
  right: -60px;
}

.speaker-card__avatar::after {
  content: '';
  position: absolute;
  width: 120px;
  height: 120px;
  border-radius: 50%;
  border: 30px solid rgba(255, 255, 255, 0.05);
  top: -30px;
  left: -30px;
}

.speaker-card__initials {
  width: 90px;
  height: 90px;
  background: rgba(255, 255, 255, 0.12);
  border: 2px solid rgba(255, 255, 255, 0.25);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-white);
  position: relative;
  z-index: 1;
  backdrop-filter: blur(4px);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.2);
  transition: transform var(--transition-base);
}

.speaker-card:hover .speaker-card__initials {
  transform: scale(1.05);
}

.speaker-card__topic-badge {
  position: absolute;
  top: var(--space-3);
  left: var(--space-3);
}

.speaker-card__body {
  padding: var(--space-5);
  border-top: 3px solid var(--color-gray-100);
  position: relative;
}

.speaker-card__body::before {
  content: '';
  position: absolute;
  top: -3px;
  left: 0;
  width: 40px;
  height: 3px;
  background: var(--color-accent);
  border-radius: 0 2px 2px 0;
}

.speaker-card__name {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-1);
}

.speaker-card__title {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  margin-bottom: var(--space-3);
  line-height: 1.4;
}

.speaker-card__org {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-primary);
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.speaker-card__org::before {
  content: '';
  width: 16px;
  height: 2px;
  background: var(--color-accent);
  border-radius: 1px;
}

/* =============================================
   SCHEDULE / TIMELINE CARDS
   ============================================= */
.schedule-item {
  display: flex;
  gap: var(--space-6);
  padding: var(--space-6) 0;
  border-bottom: 1px solid var(--color-gray-100);
  transition: all var(--transition-base);
}

.schedule-item:last-child {
  border-bottom: none;
}

.schedule-item:hover {
  background: var(--color-gray-50);
  border-radius: var(--radius-lg);
  padding-left: var(--space-4);
  padding-right: var(--space-4);
  margin: 0 calc(-1 * var(--space-4));
}

.schedule-item__time {
  flex-shrink: 0;
  width: 100px;
  padding-top: var(--space-1);
}

.schedule-item__time-text {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-primary);
}

.schedule-item__time-end {
  font-size: var(--text-xs);
  color: var(--color-gray-400);
  margin-top: var(--space-1);
}

.schedule-item__connector {
  display: flex;
  flex-direction: column;
  align-items: center;
  flex-shrink: 0;
  gap: var(--space-2);
}

.schedule-item__dot {
  width: 12px;
  height: 12px;
  background: var(--color-accent);
  border-radius: 50%;
  border: 2px solid var(--color-white);
  box-shadow: 0 0 0 2px var(--color-accent);
  flex-shrink: 0;
  margin-top: var(--space-1);
}

.schedule-item__line {
  width: 2px;
  flex: 1;
  background: var(--color-gray-200);
  min-height: 20px;
}

.schedule-item__content {
  flex: 1;
}

.schedule-item__type {
  margin-bottom: var(--space-2);
}

.schedule-item__title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-gray-900);
  margin-bottom: var(--space-2);
}

.schedule-item__desc {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  line-height: 1.6;
  margin-bottom: var(--space-3);
}

.schedule-item__meta {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.schedule-item__speaker {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-gray-700);
}

.schedule-item__speaker-avatar {
  width: 28px;
  height: 28px;
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-white);
}

.schedule-item__room {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--color-gray-400);
}

/* =============================================
   STAT CARDS / NUMBERS
   ============================================= */
.stat-card {
  text-align: center;
  padding: var(--space-8);
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-xl);
  transition: all var(--transition-base);
}

.stat-card:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: rgba(255, 255, 255, 0.15);
  transform: translateY(-4px);
}

.stat-card__number {
  font-family: var(--font-heading);
  font-size: clamp(2.5rem, 4vw, 3.5rem);
  font-weight: 800;
  color: var(--color-accent);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.stat-card__label {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.65);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  font-weight: 500;
}

/* =============================================
   COUNTDOWN TIMER
   ============================================= */
.countdown {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.countdown__item {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 80px;
}

.countdown__number {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 4vw, 3.5rem);
  font-weight: 800;
  color: var(--color-white);
  line-height: 1;
  background: rgba(255, 255, 255, 0.1);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius-lg);
  padding: var(--space-4) var(--space-5);
  min-width: 80px;
  text-align: center;
  backdrop-filter: blur(10px);
}

.countdown__label {
  font-size: var(--text-xs);
  color: rgba(255, 255, 255, 0.55);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: var(--space-2);
  font-weight: 500;
}

.countdown__separator {
  font-family: var(--font-heading);
  font-size: 2rem;
  font-weight: 800;
  color: var(--color-accent);
  align-self: flex-start;
  margin-top: var(--space-4);
  line-height: 1;
}

/* =============================================
   SPONSOR / PARTNER LOGOS
   ============================================= */
.sponsor-logo {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4) var(--space-6);
  background: var(--color-white);
  border: 1px solid var(--color-gray-100);
  border-radius: var(--radius-lg);
  transition: all var(--transition-base);
  min-height: 80px;
  filter: grayscale(100%);
  opacity: 0.65;
}

.sponsor-logo:hover {
  filter: grayscale(0%);
  opacity: 1;
  border-color: var(--color-gray-200);
  box-shadow: var(--shadow-md);
}

.sponsor-logo img {
  max-height: 40px;
  width: auto;
}

/* Sponsor text placeholder */
.sponsor-placeholder {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-gray-400);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}

/* =============================================
   TOPIC / TRACK CARDS
   ============================================= */
.topic-card {
  padding: var(--space-8);
  background: var(--color-white);
  border: 1px solid var(--color-gray-100);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  transition: all var(--transition-slow);
  position: relative;
  overflow: hidden;
}

.topic-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.topic-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-gray-200);
}

.topic-card:hover::before {
  transform: scaleX(1);
}

.topic-card__icon {
  width: 56px;
  height: 56px;
  background: linear-gradient(135deg, rgba(26, 60, 110, 0.08), rgba(42, 82, 152, 0.08));
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.75rem;
  margin-bottom: var(--space-5);
  transition: all var(--transition-base);
}

.topic-card:hover .topic-card__icon {
  background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
}

.topic-card__title {
  font-family: var(--font-heading);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-gray-900);
  margin-bottom: var(--space-3);
}

.topic-card__desc {
  font-size: var(--text-sm);
  color: var(--color-gray-500);
  line-height: 1.7;
}

/* =============================================
   FOOTER
   ============================================= */
#footer {
  background: var(--color-gray-900);
  color: rgba(255, 255, 255, 0.7);
}

.footer-top {
  padding: var(--space-24) 0 var(--space-16);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: var(--space-12);
}

.footer-brand__desc {
  font-size: var(--text-sm);
  line-height: 1.7;
  margin-top: var(--space-5);
  margin-bottom: var(--space-6);
  color: rgba(255, 255, 255, 0.55);
  max-width: 300px;
}

.footer-social {
  display: flex;
  gap: var(--space-3);
}

.footer-social__link {
  width: 38px;
  height: 38px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.08);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-base);
  color: rgba(255, 255, 255, 0.6);
  transition: all var(--transition-base);
}

.footer-social__link:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
  transform: translateY(-2px);
}

.footer-col__title {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: var(--space-5);
}

.footer-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer-link {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.55);
  transition: color var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.footer-link:hover {
  color: var(--color-accent);
}

.footer-contact-item {
  display: flex;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.55);
  line-height: 1.5;
}

.footer-contact-icon {
  font-size: 1rem;
  flex-shrink: 0;
  margin-top: 2px;
  opacity: 0.7;
}

.footer-bottom {
  padding: var(--space-6) 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.footer-copyright {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.35);
}

.footer-bottom-links {
  display: flex;
  gap: var(--space-5);
}

.footer-bottom-link {
  font-size: var(--text-sm);
  color: rgba(255, 255, 255, 0.35);
  transition: color var(--transition-fast);
}

.footer-bottom-link:hover {
  color: rgba(255, 255, 255, 0.7);
}

@media (max-width: 1024px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--space-8);
  }
}

@media (max-width: 640px) {
  .footer-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .footer-bottom {
    flex-direction: column;
    text-align: center;
  }

  .countdown {
    justify-content: center;
  }

  .countdown__item {
    min-width: 60px;
  }
}

/* =============================================
   REGISTRATION TABLES
   ============================================= */
.reg__tables-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(400px, 1fr));
  gap: var(--space-8);
}

.reg__table {
  background: var(--color-white);
  border-radius: var(--radius-xl);
  border: 1px solid var(--color-gray-100);
  overflow: hidden;
  box-shadow: var(--shadow-md);
}

.reg__table-header {
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-6);
  text-align: center;
}

.reg__table-flag {
  font-size: 2rem;
  margin-bottom: var(--space-2);
}

.reg__table-title {
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-1);
}

.reg__table-currency {
  font-size: var(--text-xs);
  opacity: 0.7;
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.reg__table-row {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  padding: var(--space-4) var(--space-6);
  border-bottom: 1px solid var(--color-gray-50);
  align-items: center;
}

.reg__table-row:last-child {
  border-bottom: none;
}

.reg__table-row--header {
  background: var(--color-gray-50);
  font-weight: 700;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-gray-500);
}

/* Right justify the fee columns */
.reg__table-row span:nth-child(2),
.reg__table-row span:nth-child(3) {
  text-align: right;
  font-family: var(--font-heading);
  font-weight: 600;
}

.reg__price-early {
  color: var(--color-accent-dark);
}

.reg__price-regular {
  color: var(--color-gray-700);
}

.reg__paypal-section {
  margin-top: var(--space-12);
}

.reg__paypal-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
  margin-top: var(--space-6);
}

.reg__paypal-card {
  background: var(--color-white);
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  border: 1px solid var(--color-gray-100);
  transition: all var(--transition-base);
}

.reg__paypal-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.reg__paypal-title {
  font-family: var(--font-heading);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.reg__paypal-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.reg__paypal-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-accent-dark);
  text-decoration: none;
  padding: var(--space-2) var(--space-3);
  background: rgba(245, 166, 35, 0.08);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.reg__paypal-link:hover {
  background: var(--color-accent);
  color: var(--color-white);
}