/* =============================================
   COLDCOFE × JSTU — IELTS & HIGHER STUDY WEBINAR
   Bootstrap 5.3.8 + Material Design 3
   Event 4 — Premium Light/Dark Stylesheet
   ============================================= */

/* --- Google Fonts --- */
@import url("https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&family=Outfit:wght@300;400;500;600;700;800;900&family=Hind+Siliguri:wght@300;400;500;600;700&display=swap");

/* --- CSS Variables --- */
:root {
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc; /* Slate 50 */
  --bg-card: rgba(255, 255, 255, 0.75);
  --bg-card-hover: rgba(255, 255, 255, 0.98);
  --border: rgba(15, 23, 42, 0.08); /* Slate 900 at 8% */
  --border-glow: rgba(79, 70, 229, 0.2); /* Indigo 600 at 20% */

  --grad-primary: linear-gradient(
    135deg,
    #0284c7 0%,
    #4f46e5 100%
  ); /* Cyan to Indigo */
  --grad-subtle: linear-gradient(
    135deg,
    rgba(2, 132, 199, 0.06) 0%,
    rgba(79, 70, 229, 0.06) 100%
  );
  --grad-light: linear-gradient(180deg, #ffffff 0%, #f8fafc 100%);

  --accent-blue: #0284c7;
  --accent-purple: #4f46e5;
  --accent-gold: #d97706; /* High contrast amber on white */
  --accent-teal: #0d9488;

  --text-primary: #0f172a; /* Slate 900 */
  --text-secondary: #334155; /* Slate 700 */
  --text-muted: #64748b; /* Slate 500 */

  --font-main: "Outfit", "Inter", sans-serif;
  --font-body: "Inter", sans-serif;
  --font-bengali: "Hind Siliguri", sans-serif;

  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --radius-xl: 32px;

  --shadow-glow: 0 10px 30px rgba(2, 132, 199, 0.06);
  --shadow-card:
    0 10px 25px -5px rgba(15, 23, 42, 0.05),
    0 8px 10px -6px rgba(15, 23, 42, 0.05);
  --shadow-btn: 0 8px 25px rgba(79, 70, 229, 0.2);

  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --nav-height: 72px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-body);
  background: linear-gradient(
    -45deg,
    var(--grad-sky-1, #e0f2fe),
    var(--grad-sky-2, #bae6fd),
    var(--grad-sky-3, #7dd3fc),
    var(--grad-sky-4, #38bdf8)
  );
  background-size: 400% 400%;
  animation: gradientShift 15s ease infinite;
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

@media (prefers-reduced-motion: reduce) {
  body { animation: none; background-position: 0% 50%; }
  .animate-float, .animate-pulse-glow { animation: none; }
  .reveal { opacity: 1; transform: none; transition: none; }
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  z-index: 10000;
  padding: 12px 24px;
  background: var(--accent-purple);
  color: #fff;
  border-radius: var(--radius-sm);
  font-weight: 600;
  transition: top 0.2s;
}

.skip-link:focus {
  top: 16px;
}

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

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--accent-purple);
  outline-offset: 2px;
}
::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: var(--bg-secondary);
}

::-webkit-scrollbar-thumb {
  background: var(--accent-blue);
  border-radius: 4px;
}

/* --- Utility --- */
.container {
  max-width: 1160px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
  position: relative;
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: var(--grad-subtle);
  border: 1px solid var(--border-glow);
  border-radius: 100px;
  padding: 6px 18px;
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent-purple);
  margin-bottom: 20px;
}

.section-title {
  font-family: var(--font-main);
  font-size: clamp(2rem, 4vw, 2.6rem);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.section-subtitle {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 600px;
  line-height: 1.7;
  text-align: justify;
}

.gradient-text {
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.glass-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  box-shadow: var(--shadow-card);
  transition:
    background var(--transition),
    border-color var(--transition),
    transform var(--transition),
    box-shadow var(--transition);
}

.glass-card:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-glow);
  box-shadow: var(--shadow-glow), var(--shadow-card);
}

.tilt-3d {
  transform-style: preserve-3d;
  will-change: transform;
  transition: box-shadow 0.3s ease;
}

.tilt-3d:hover {
  box-shadow: var(--md-elevation-3, var(--shadow-glow)), var(--shadow-card);
}

.glass-card:not(.tilt-3d):hover {
  transform: translateY(-4px);
}

.glass-card .learn-icon,
.glass-card .learn-num,
.glass-card h3 {
  text-align: center;
}

.glass-card p {
  text-align: justify;
}

/* --- Buttons --- */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--grad-primary);
  color: #fff;
  font-family: var(--font-main);
  font-weight: 700;
  font-size: 1rem;
  padding: 15px 36px;
  border-radius: 100px;
  border: none;
  cursor: pointer;
  transition:
    transform var(--transition),
    box-shadow var(--transition),
    opacity var(--transition);
  box-shadow: var(--shadow-btn);
  position: relative;
  overflow: hidden;
  text-decoration: none;
}

.btn-primary::after {
  content: "";
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0);
  transition: background var(--transition);
}

.btn-primary:hover {
  transform: translateY(-3px) scale(1.02);
  box-shadow: 0 12px 36px rgba(79, 70, 229, 0.4);
}

.btn-primary:hover::after {
  background: rgba(255, 255, 255, 0.08);
}

.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  color: var(--accent-purple);
  font-family: var(--font-main);
  font-weight: 600;
  font-size: 0.95rem;
  padding: 13px 28px;
  border-radius: 100px;
  border: 1.5px solid var(--border-glow);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
}

.btn-secondary:hover {
  background: rgba(79, 70, 229, 0.05);
  border-color: var(--accent-purple);
  transform: translateY(-2px);
}

/* =============================================
   NAVIGATION
   ============================================= */
#navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition:
    background var(--transition),
    border-bottom-color var(--transition),
    box-shadow var(--transition);
  border-bottom: 1px solid transparent;
}

#navbar.scrolled {
  background: rgba(255, 255, 255, 0.85);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border-bottom-color: var(--border);
  box-shadow: 0 4px 20px rgba(15, 23, 42, 0.04);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.org-logo {
  height: 28px;
  width: auto;
  max-width: 36px;
  object-fit: contain;
  border-radius: 4px;
  flex-shrink: 0;
}

.org-logo--round {
  width: 22px;
  height: 22px;
  max-width: 22px;
  border-radius: 50%;
  object-fit: cover;
}

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-main);
  font-weight: 800;
  font-size: 1.2rem;
}

.nav-logo-icon {
  width: 38px;
  height: 38px;
  background: transparent;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  overflow: hidden;
  flex-shrink: 0;
}

.nav-logo-icon img {
  width: 38px;
  height: 38px;
  object-fit: cover;
  border-radius: 50%;
}

.nav-logo span {
  color: var(--text-primary);
}

.nav-logo em {
  color: var(--accent-purple);
  font-style: normal;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: color var(--transition);
}

.nav-links a:hover {
  color: var(--accent-purple);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-left: 16px;
}

.nav-cta {
  margin-left: 0;
}

.theme-toggle {
  width: 44px;
  height: 44px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: var(--bg-card);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.15rem;
  transition: all var(--transition);
}

.theme-toggle:hover {
  border-color: var(--border-glow);
  color: var(--accent-purple);
  transform: translateY(-2px);
}

.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}

.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition);
}

/* Mobile Nav */
.mobile-nav {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0;
  right: 0;
  background: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(24px);
  padding: 24px;
  border-bottom: 1px solid var(--border);
  z-index: 999;
  flex-direction: column;
  gap: 20px;
  transform: translateY(-100%);
  transition: transform var(--transition);
  box-shadow: 0 10px 20px rgba(15, 23, 42, 0.05);
}

.mobile-nav.open {
  display: flex;
  transform: translateY(0);
}

.mobile-nav a {
  font-size: 1rem;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
}

/* =============================================
   HERO SECTION
   ============================================= */
#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
  padding-top: var(--nav-height);
  background: transparent;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background-image: url("../media/feature.png");
  background-size: cover;
  background-position: center;
  opacity: 0.6;
  z-index: 0;
}

.hero-bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(224, 242, 254, 0.3) 0%,
    rgba(240, 249, 255, 0.85) 100%
  );
}

.hero-glow {
  position: absolute;
  width: 800px;
  height: 800px;
  border-radius: 50%;
  background: radial-gradient(
    circle,
    rgba(2, 132, 199, 0.06) 0%,
    transparent 70%
  );
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  z-index: 0;
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 950px;
  margin: 0 auto;
  padding: 80px 0 60px;
}

.hero-badges {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 28px;
}

.badge {
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.badge-free {
  background: rgba(2, 132, 199, 0.08);
  color: var(--accent-blue);
  border: 1px solid rgba(2, 132, 199, 0.2);
}

.badge-online {
  background: rgba(79, 70, 229, 0.08);
  color: var(--accent-purple);
  border: 1px solid rgba(79, 70, 229, 0.2);
}

.badge-bangla {
  background: rgba(217, 119, 6, 0.08);
  color: var(--accent-gold);
  border: 1px solid rgba(217, 119, 6, 0.2);
}

.badge-gmeet {
  background: rgba(13, 148, 136, 0.08);
  color: var(--accent-teal);
  border: 1px solid rgba(13, 148, 136, 0.2);
}

.badge-duration {
  background: rgba(99, 102, 241, 0.08);
  color: var(--accent-purple);
  border: 1px solid rgba(99, 102, 241, 0.2);
}

.hero-title {
  font-family: var(--font-main);
  font-size: clamp(2.4rem, 6vw, 3.8rem);
  font-weight: 900;
  line-height: 1.15;
  margin-bottom: 20px;
  letter-spacing: -0.02em;
  color: var(--text-primary);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--text-secondary);
  margin-bottom: 12px;
  line-height: 1.7;
}

.hero-bengali {
  font-family: var(--font-bengali);
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 36px;
}

/* Countdown */
.countdown-wrapper {
  margin-bottom: 40px;
}

.countdown-label {
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-purple);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 16px;
}

.countdown {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 20px 32px;
  backdrop-filter: blur(20px);
  box-shadow: var(--shadow-card);
}

.countdown-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 64px;
}

.countdown-number {
  font-family: var(--font-main);
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 900;
  line-height: 1;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  transition: transform 0.2s;
}

.countdown-unit {
  font-size: 0.68rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-top: 6px;
}

.countdown-sep {
  font-size: 2rem;
  font-weight: 900;
  color: var(--border-glow);
  line-height: 1;
  padding-bottom: 16px;
}

.hero-ctas {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 60px;
}

.hero-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap;
  gap: 28px;
  color: var(--text-secondary);
  font-size: 0.95rem;
}

.hero-meta-item {
  display: flex;
  align-items: center;
  gap: 8px;
}

.hero-meta-item .icon {
  color: var(--accent-purple);
  font-size: 1.1rem;
}

.orgs-row {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
}

.orgs-tags {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.org-tag {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 100px;
  padding: 8px 20px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.02);
}

.org-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--grad-primary);
}

/* Divider */
.section-divider {
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--border), transparent);
  margin: 0 auto;
}

/* =============================================
   ABOUT SECTION
   ============================================= */
#about {
  background: rgba(248, 250, 252, 0.75);
  backdrop-filter: blur(8px);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.about-highlights {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-top: 36px;
}

.highlight-card {
  padding: 24px;
  text-align: center;
}

.highlight-icon {
  font-size: 2rem;
  margin-bottom: 10px;
}

.highlight-value {
  font-family: var(--font-main);
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--accent-purple);
  margin-bottom: 4px;
}

.highlight-label {
  font-size: 0.82rem;
  color: var(--text-muted);
  font-weight: 500;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.feature-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 24px;
}

.feature-icon-wrap {
  width: 48px;
  height: 48px;
  min-width: 48px;
  border-radius: 12px;
  background: var(--grad-subtle);
  border: 1px solid var(--border-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.3rem;
}

.feature-text h4 {
  font-family: var(--font-main);
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.feature-text p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* =============================================
   LEARN SECTION
   ============================================= */
#learn {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
}

.learn-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 24px;
  margin-top: 60px;
}

.learn-card {
  padding: 32px 28px;
  position: relative;
  overflow: hidden;
}

.learn-card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--grad-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.learn-card:hover::before {
  opacity: 1;
}

.learn-num {
  font-family: var(--font-main);
  font-size: 3rem;
  font-weight: 900;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  opacity: 0.15;
  line-height: 1;
  margin-bottom: 12px;
}

.learn-card h3 {
  font-family: var(--font-main);
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.learn-card p {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.learn-icon {
  font-size: 2rem;
  margin-bottom: 16px;
}

/* =============================================
   SPEAKER SECTION
   ============================================= */
#speaker {
  background: rgba(248, 250, 252, 0.75);
  backdrop-filter: blur(8px);
}

.speakers-wrapper {
  display: flex;
  flex-direction: column;
  gap: 80px;
}

.speaker-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 64px;
  align-items: center;
}

.speaker-grid.reverse {
  direction: rtl;
}

.speaker-grid.reverse > * {
  direction: ltr;
}

.speaker-card {
  padding: 40px 32px;
  text-align: center;
}

.speaker-photo-wrap {
  position: relative;
  width: 180px;
  height: 180px;
  margin: 0 auto 24px;
}

.speaker-photo {
  width: 180px;
  height: 180px;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid transparent;
  position: relative;
  z-index: 1;
}

.speaker-photo-ring {
  position: absolute;
  inset: -4px;
  border-radius: 50%;
  background: var(--grad-primary);
  z-index: 0;
}

.speaker-name {
  font-family: var(--font-main);
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 6px;
  color: var(--text-primary);
}

.speaker-title {
  font-size: 0.9rem;
  color: var(--accent-purple);
  font-weight: 600;
  margin-bottom: 4px;
}

.speaker-company {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: 20px;
}

.speaker-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  justify-content: center;
  margin-bottom: 24px;
}

.speaker-tag {
  padding: 4px 12px;
  background: var(--grad-subtle);
  border: 1px solid var(--border-glow);
  border-radius: 100px;
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-purple);
}

.speaker-social {
  display: flex;
  gap: 12px;
  justify-content: center;
}

.speaker-social a {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
  color: var(--text-secondary);
  transition: all var(--transition);
}

.speaker-social a:hover {
  background: var(--accent-purple);
  border-color: var(--accent-purple);
  color: #ffffff;
  transform: translateY(-2px);
}

.speaker-bio h2 {
  font-family: var(--font-main);
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 20px;
  line-height: 1.3;
  color: var(--text-primary);
}

.speaker-bio p {
  color: var(--text-secondary);
  line-height: 1.8;
  margin-bottom: 16px;
}

.speaker-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin-top: 36px;
}

.stat-box {
  padding: 20px 16px;
  text-align: center;
}

.stat-val {
  font-family: var(--font-main);
  font-size: 1.6rem;
  font-weight: 800;
  background: var(--grad-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.stat-lbl {
  font-size: 0.78rem;
  color: var(--text-muted);
  font-weight: 500;
  margin-top: 4px;
}

/* =============================================
   AGENDA SECTION
   ============================================= */
#agenda {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
}

/* =============================================
   SPONSORS SECTION
   ============================================= */
#sponsors {
  background: rgba(248, 250, 252, 0.75);
  backdrop-filter: blur(8px);
}

.sponsor-header {
  text-align: center;
  margin-bottom: 48px;
}

.sponsor-card-wrap {
  max-width: 720px;
  margin: 0 auto;
}

.sponsor-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: 48px 40px;
  gap: 20px;
}

.sponsor-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: rgba(217, 119, 6, 0.1);
  border: 1px solid rgba(217, 119, 6, 0.25);
  border-radius: 100px;
  padding: 6px 18px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--accent-gold);
}

.sponsor-logo {
  width: 200px;
  height: 80px;
  object-fit: contain;
}

.sponsor-name {
  font-family: var(--font-main);
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--text-primary);
}

.sponsor-desc {
  font-family: var(--font-bengali), var(--font-body);
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.8;
  max-width: 560px;
}

.sponsor-services {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  width: 100%;
  margin-top: 16px;
}

.service-box {
  padding: 20px 16px;
  text-align: center;
}

.service-box-icon {
  font-size: 1.8rem;
  margin-bottom: 8px;
}

.service-box h4 {
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 700;
  margin-bottom: 4px;
  color: var(--text-primary);
}

.service-box p {
  font-size: 0.78rem;
  color: var(--text-muted);
  line-height: 1.4;
}

.agenda-header {
  text-align: center;
  margin-bottom: 64px;
}

.timeline {
  position: relative;
  max-width: 800px;
  margin: 0 auto;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 48px;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--accent-blue), var(--accent-purple));
  border-radius: 2px;
}

.timeline-item {
  display: flex;
  gap: 32px;
  margin-bottom: 28px;
  align-items: flex-start;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot-col {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 96px;
}

.timeline-dot {
  width: 20px;
  height: 20px;
  border-radius: 50%;
  background: var(--grad-primary);
  box-shadow: 0 0 12px rgba(79, 70, 229, 0.3);
  position: relative;
  z-index: 1;
  margin-top: 20px;
  flex-shrink: 0;
}

.timeline-time {
  font-family: var(--font-main);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-purple);
  margin-top: 8px;
  white-space: nowrap;
  text-align: center;
}

.timeline-card {
  flex: 1;
  padding: 24px 28px;
}

.timeline-card-title {
  font-family: var(--font-main);
  font-size: 1.05rem;
  font-weight: 700;
  margin-bottom: 6px;
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text-primary);
}

.timeline-card-title .tl-icon {
  font-size: 1.2rem;
}

.timeline-card-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.tl-special {
  border-color: rgba(217, 119, 6, 0.3) !important;
  background: rgba(217, 119, 6, 0.03) !important;
}

/* =============================================
   REGISTRATION SECTION
   ============================================= */
#register {
  background: rgba(248, 250, 252, 0.75);
  backdrop-filter: blur(8px);
}

.register-grid {
  display: grid;
  grid-template-columns: 1fr 1.2fr;
  gap: 64px;
  align-items: start;
}

.register-info h2 {
  font-family: var(--font-main);
  font-size: 2.2rem;
  font-weight: 800;
  margin-bottom: 16px;
  line-height: 1.2;
  color: var(--text-primary);
}

.register-info p {
  color: var(--text-secondary);
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 32px;
}

.register-perks {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

@keyframes perk-shimmer {
  0% {
    background-position: -200% center;
  }
  100% {
    background-position: 200% center;
  }
}

.register-perks a {
  position: relative;
  display: inline;
  font-weight: 700;
  text-decoration: none;
  color: transparent;
  background: linear-gradient(
    90deg,
    var(--accent-blue) 0%,
    var(--accent-purple) 30%,
    var(--accent-blue) 60%,
    var(--accent-teal) 80%,
    var(--accent-blue) 100%
  );
  background-size: 200% auto;
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  animation: perk-shimmer 3s linear infinite;
  transition: filter var(--transition);
}

.register-perks a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 0;
  height: 1.5px;
  background: linear-gradient(90deg, var(--accent-blue), var(--accent-purple));
  border-radius: 2px;
  transition: width 0.35s cubic-bezier(0.4, 0, 0.2, 1);
}

.register-perks a:hover {
  filter: brightness(1.15) drop-shadow(0 0 4px rgba(79, 70, 229, 0.2));
}

.register-perks a:hover::after {
  width: 100%;
}

.perk-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.perk-check {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  background: rgba(79, 70, 229, 0.08);
  border: 1px solid var(--border-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  color: var(--accent-purple);
  flex-shrink: 0;
}

.register-form-wrap {
  padding: 40px;
}

.form-title {
  font-family: var(--font-main);
  font-size: 1.4rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.yt-embed-wrap {
  position: relative;
  width: 100%;
  padding-top: 56.25%;
  border-radius: var(--radius-md);
  overflow: hidden;
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
  margin: 16px 0 6px;
  background: #000;
}

.yt-embed-wrap iframe {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  border: none;
  display: block;
}

.yt-embed-caption {
  font-family: var(--font-bengali), var(--font-body);
  font-size: 0.8rem;
  color: var(--text-muted);
  text-align: center;
  margin-bottom: 20px;
  line-height: 1.5;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  background: #ffffff;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.95rem;
  padding: 13px 16px;
  outline: none;
  transition:
    border-color var(--transition),
    background var(--transition),
    box-shadow var(--transition);
  -webkit-appearance: none;
}

.form-group input::placeholder {
  color: var(--text-muted);
}

.form-group input:focus,
.form-group select:focus {
  border-color: var(--accent-purple);
  background: rgba(79, 70, 229, 0.02);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

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

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.form-submit {
  width: 100%;
  margin-top: 8px;
  padding: 16px;
  font-size: 1.05rem;
}

.calendar-cta {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-top: 24px;
  padding: 14px 20px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  text-decoration: none;
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.02);
}

.calendar-cta:hover {
  border-color: var(--border-glow);
  background: var(--bg-card-hover);
  color: var(--accent-purple);
  box-shadow: var(--shadow-card);
}

.form-success {
  display: none;
  text-align: center;
  padding: 48px 24px;
}

.form-success[hidden] {
  display: none !important;
}

.success-icon {
  font-size: 4rem;
  margin-bottom: 16px;
}

.form-success h3 {
  font-family: var(--font-main);
  font-size: 1.6rem;
  font-weight: 800;
  margin-bottom: 10px;
  color: var(--text-primary);
}

.form-success p {
  color: var(--text-secondary);
  font-size: 0.95rem;
}

/* =============================================
   CERTIFICATE SECTION
   ============================================= */
#certificate {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(8px);
}

.cert-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.cert-image-wrap {
  position: relative;
}

.cert-image-wrap::after {
  content: "";
  position: absolute;
  inset: -20px;
  border-radius: var(--radius-xl);
  background: var(--grad-subtle);
  z-index: -1;
  filter: blur(30px);
}

.cert-image {
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-card);
}

.cert-info h2 {
  font-family: var(--font-main);
  font-size: 2.2rem;
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: 16px;
  color: var(--text-primary);
}

.cert-info p {
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 28px;
}

.cert-steps {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.cert-step {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.cert-step-num {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  background: var(--grad-primary);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-main);
  font-weight: 800;
  font-size: 0.9rem;
  flex-shrink: 0;
}

.cert-step-text h4 {
  font-weight: 700;
  font-size: 0.95rem;
  margin-bottom: 2px;
  color: var(--text-primary);
}

.cert-step-text p {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 0;
}

/* =============================================
   COMMUNITY SECTION
   ============================================= */
#community {
  background: rgba(248, 250, 252, 0.75);
  backdrop-filter: blur(8px);
}

.community-header {
  text-align: center;
  margin-bottom: 64px;
}

.social-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
  gap: 16px;
  margin-bottom: 64px;
}

.social-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 28px 20px;
  text-align: center;
  text-decoration: none;
  position: relative;
  overflow: hidden;
}

.social-card::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  border-radius: 0 0 var(--radius-md) var(--radius-md);
  transition: opacity var(--transition);
  opacity: 0;
}

.social-card:hover::after {
  opacity: 1;
}

.social-icon {
  font-size: 2rem;
}

.social-name {
  font-family: var(--font-main);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--text-primary);
}

.social-handle {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.sc-facebook::after {
  background: #1877f2;
}
.sc-linkedin::after {
  background: #0a66c2;
}
.sc-youtube::after {
  background: #ff0000;
}
.sc-x::after {
  background: #0f1419;
}
.sc-hf::after {
  background: #ffd21e;
}
.sc-reddit::after {
  background: #ff4500;
}
.sc-instagram::after {
  background: linear-gradient(45deg, #f58529, #dd2a7b, #8134af);
}
.sc-tiktok::after {
  background: #010101;
}

/* YouTube Videos */
.yt-section {
  border-top: 1px solid var(--border);
  padding-top: 64px;
}

.yt-section-title {
  font-family: var(--font-main);
  font-size: 1.5rem;
  font-weight: 800;
  margin-bottom: 8px;
  color: var(--text-primary);
}

.yt-section-sub {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 32px;
}

.yt-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.yt-card {
  display: flex;
  align-items: flex-start;
  gap: 16px;
  padding: 20px;
  text-decoration: none;
}

.yt-thumb {
  width: 64px;
  height: 48px;
  border-radius: 8px;
  background: rgba(255, 0, 0, 0.08);
  border: 1px solid rgba(255, 0, 0, 0.15);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  flex-shrink: 0;
  transition: all var(--transition);
}

.yt-card:hover .yt-thumb {
  background: rgba(255, 0, 0, 0.15);
  border-color: rgba(255, 0, 0, 0.3);
}

.yt-title {
  font-size: 0.875rem;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.4;
  margin-bottom: 4px;
  transition: color var(--transition);
}

.yt-card:hover .yt-title {
  color: var(--accent-purple);
}

.yt-sub {
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* ColdCofe Platform Join */
.platform-join {
  margin-top: 64px;
  padding: 60px 48px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

.platform-join::before {
  content: "";
  position: absolute;
  inset: 0;
  background: var(--grad-subtle);
  border-radius: inherit;
}

.platform-join > * {
  position: relative;
  z-index: 1;
}

.platform-join h3 {
  font-family: var(--font-main);
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--text-primary);
}

.platform-join p {
  color: var(--text-secondary);
  margin-bottom: 28px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* =============================================
   FOOTER
   ============================================= */
#footer {
  background: #ffffff;
  padding: 48px 0 32px;
  border-top: 1px solid var(--border);
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 28px;
  text-align: center;
}

.footer-logo {
  font-family: var(--font-main);
  font-size: 1.3rem;
  font-weight: 800;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.footer-logo span:first-child {
  font-size: 1.2rem;
}

.footer-logo-img {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.footer-social {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  justify-content: center;
}

.footer-social a {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: all var(--transition);
  color: var(--text-secondary);
}

.footer-social a:hover {
  background: var(--accent-purple);
  border-color: var(--accent-purple);
  color: #ffffff;
  transform: translateY(-2px);
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}

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

.footer-links a:hover {
  color: var(--accent-purple);
}

.footer-copy {
  font-size: 0.82rem;
  color: var(--text-muted);
  line-height: 1.6;
}

.footer-copy a {
  color: var(--accent-purple);
  font-weight: 600;
}

/* =============================================
   ANIMATIONS
   ============================================= */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

@keyframes pulse-glow {
  0%,
  100% {
    box-shadow: 0 0 15px rgba(79, 70, 229, 0.2);
  }
  50% {
    box-shadow: 0 0 30px rgba(79, 70, 229, 0.45);
  }
}

.animate-float {
  animation: float 4s ease-in-out infinite;
}

.animate-pulse-glow {
  animation: pulse-glow 2.5s ease-in-out infinite;
}

.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition:
    opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
    transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

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

/* =============================================
   SCROLL-TO-TOP BUTTON
   ============================================= */
@keyframes stt-appear {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.8);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes stt-orbit-1 {
  from {
    transform: rotate(0deg);
  }
  to {
    transform: rotate(360deg);
  }
}

@keyframes stt-orbit-2 {
  from {
    transform: rotate(180deg);
  }
  to {
    transform: rotate(-180deg);
  }
}

@keyframes stt-bob {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-3px);
  }
}

@keyframes stt-glow-pulse {
  0%,
  100% {
    box-shadow:
      0 0 15px rgba(2, 132, 199, 0.3),
      0 4px 15px rgba(15, 23, 42, 0.08);
  }
  50% {
    box-shadow:
      0 0 30px rgba(79, 70, 229, 0.5),
      0 4px 20px rgba(15, 23, 42, 0.08);
  }
}

#scroll-top-btn {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 9999;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: none;
  cursor: pointer;
  outline: none;
  background: linear-gradient(
    135deg,
    var(--accent-blue) 0%,
    var(--accent-purple) 100%
  );
  color: #ffffff;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transform: translateY(20px) scale(0.8);
  transition:
    opacity 0.35s ease,
    transform 0.35s ease;
  animation: stt-glow-pulse 2.8s ease-in-out infinite;
}

#scroll-top-btn.stt-visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0) scale(1);
  animation:
    stt-appear 0.4s ease both,
    stt-glow-pulse 2.8s 0.4s ease-in-out infinite;
}

.stt-ring {
  position: absolute;
  inset: -6px;
  border-radius: 50%;
  border: 1.5px solid transparent;
  pointer-events: none;
  transition: border-color 0.3s ease;
}

.stt-ring-2 {
  inset: -12px;
}

.stt-arrow {
  font-size: 1.4rem;
  transition: transform 0.3s ease;
  display: block;
  line-height: 1;
}

.stt-label {
  font-family: var(--font-main);
  font-size: 0.52rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: rgba(255, 255, 255, 0.85);
  line-height: 1;
  margin-top: 2px;
  transition:
    color 0.3s ease,
    letter-spacing 0.3s ease;
}

#scroll-top-btn:hover .stt-ring {
  border-top-color: rgba(2, 132, 199, 0.9);
  border-right-color: rgba(2, 132, 199, 0.3);
  border-bottom-color: rgba(2, 132, 199, 0);
  border-left-color: rgba(2, 132, 199, 0.3);
  animation: stt-orbit-1 0.9s linear infinite;
}

#scroll-top-btn:hover .stt-ring-2 {
  border-top-color: rgba(79, 70, 229, 0);
  border-right-color: rgba(79, 70, 229, 0.8);
  border-bottom-color: rgba(79, 70, 229, 0.3);
  border-left-color: rgba(79, 70, 229, 0);
  animation: stt-orbit-2 1.3s linear infinite;
}

#scroll-top-btn:hover .stt-arrow {
  animation: stt-bob 0.6s ease-in-out infinite;
}

#scroll-top-btn:hover .stt-label {
  color: #ffffff;
  letter-spacing: 0.18em;
}

#scroll-top-btn:hover {
  background: linear-gradient(135deg, #00d2ff 0%, #8b24ff 100%);
}

#scroll-top-btn:active {
  transform: scale(0.9);
  box-shadow: 0 0 8px rgba(2, 132, 199, 0.4);
}

/* =============================================
   RESPONSIVE
   ============================================= */
@media (max-width: 1023px) {
  .about-grid,
  .speaker-grid,
  .register-grid,
  .cert-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .speaker-grid,
  .speaker-grid.reverse {
    grid-template-columns: 1fr;
    max-width: 600px;
    margin: 0 auto;
    direction: ltr;
  }

  .speaker-grid.reverse > * {
    direction: ltr;
  }

  .sponsor-services {
    grid-template-columns: 1fr;
  }

  .about-highlights {
    grid-template-columns: repeat(4, 1fr);
  }

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

  .timeline::before {
    left: 36px;
  }

  .timeline-dot-col {
    min-width: 72px;
  }
}

@media (max-width: 768px) {
  .section {
    padding: 72px 0;
  }

  .nav-links,
  .nav-actions {
    display: none;
  }

  .sponsor-services {
    grid-template-columns: 1fr;
  }

  .hamburger {
    display: flex;
  }

  .hero-title {
    font-size: 2rem;
  }

  .countdown {
    padding: 16px 20px;
    gap: 8px;
  }

  .countdown-number {
    font-size: 2rem;
  }

  .countdown-item {
    min-width: 50px;
  }

  .about-highlights {
    grid-template-columns: 1fr 1fr;
  }

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

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

  .social-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .platform-join {
    padding: 40px 24px;
  }

  .timeline::before {
    display: none;
  }

  .timeline-item {
    flex-direction: column;
    gap: 16px;
  }

  .timeline-dot-col {
    flex-direction: row;
    align-items: center;
    gap: 12px;
    min-width: auto;
  }

  .timeline-dot {
    margin-top: 0;
  }
}

@media (max-width: 480px) {
  .countdown {
    gap: 4px;
    padding: 14px 16px;
  }

  .countdown-item {
    min-width: 42px;
  }

  .countdown-number {
    font-size: 1.6rem;
  }

  .countdown-sep {
    font-size: 1.4rem;
    padding-bottom: 12px;
  }

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

  .social-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .speaker-stats {
    grid-template-columns: 1fr;
  }

  .about-highlights {
    grid-template-columns: 1fr 1fr;
  }
}