* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Arial,
    sans-serif;
  line-height: 1.6;
}

*:focus {
  outline: none;
}

.header {
  background: #ffffff;
  padding: 20px 40px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.nav {
  display: flex;
  gap: 30px;
}

.nav-item a {
  color: #999999;
  text-decoration: none;
  font-size: 14px;
  transition: color 0.3s;
}

.nav-item a:hover {
  color: #6366f1;
}

.hero {
  position: relative;
  height: 600px;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-video {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  color: white;
  padding: 20px;
  background: rgba(0, 0, 0, 0.5);
  border-radius: 10px;
}

.hero-content h3 {
  font-size: 24px;
  margin-bottom: 10px;
  font-weight: 300;
}

.hero-content h1 {
  font-size: 48px;
  margin-bottom: 15px;
}

.hero-date {
  font-size: 20px;
  font-weight: 300;
}

.content {
  max-width: 1200px;
  margin: 0 auto;
  padding: 40px 20px;
}

.section {
  margin-bottom: 60px;
}

.about-section h3 {
  font-size: 36px;
  color: #1a1a1a;
  margin-bottom: 15px;
}

.intro-text {
  font-size: 12px;
  color: #aaaaaa;
  line-height: 1.8;
}

.about-section h1 {
  font-size: 28px;
  color: #2d2d2d;
  margin-bottom: 25px;
}

.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 25px;
  margin-top: 25px;
}

.feature {
  padding: 25px;
  background: #f8f9fa;
  border-radius: 8px;
}

.feature h2 {
  font-size: 22px;
  color: #6366f1;
  margin-bottom: 8px;
}

.feature p {
  font-size: 14px;
  color: #666666;
}

.speakers-section h2 {
  font-size: 32px;
  color: #1a1a1a;
  margin-bottom: 20px;
}

.speakers-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
}

.speaker-card {
  background: white;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
  transition: transform 0.3s;
}

.speaker-card:hover {
  transform: translateY(-5px);
}

.speaker-img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 12px;
}

.speaker-card h3 {
  font-size: 20px;
  color: #1a1a1a;
  margin-bottom: 5px;
}

.speaker-title {
  font-size: 13px;
  color: #999999;
  margin-bottom: 8px;
  font-weight: 600;
}

.speaker-card p:last-child {
  font-size: 13px;
  color: #666666;
}

.register-section {
  background: #f8f9fa;
  padding: 40px;
  border-radius: 10px;
}

.register-section h2 {
  font-size: 32px;
  color: #1a1a1a;
  margin-bottom: 10px;
}

.register-section > p {
  font-size: 15px;
  color: #666666;
}

.form-container {
  max-width: 500px;
  margin: 25px auto 0;
}

.form-group {
  margin-bottom: 15px;
}

.input-field {
  width: 100%;
  padding: 12px 15px;
  font-size: 14px;
  border: 1px solid #ddd;
  border-radius: 5px;
  background: white;
}

.input-field::placeholder {
  color: #999999;
}

.custom-select {
  position: relative;
  background: white;
  border: 1px solid #ddd;
  border-radius: 5px;
  cursor: pointer;
}

.select-trigger {
  padding: 12px 15px;
  font-size: 14px;
  color: #999999;
}

.submit-btn {
  background: #6366f1;
  color: white;
  padding: 14px 30px;
  text-align: center;
  border-radius: 5px;
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s;
  display: inline-block;
}

.submit-btn:hover {
  background: #4f46e5;
}

.footer {
  background: #1a1a1a;
  color: white;
  padding: 40px 20px 20px;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 30px;
  margin-bottom: 25px;
}

.footer-section h4 {
  font-size: 16px;
  margin-bottom: 12px;
  color: #6366f1;
}

.footer-section p {
  font-size: 13px;
  color: #aaaaaa;
  margin-bottom: 5px;
}

.footer-link {
  display: block;
  font-size: 13px;
  color: #aaaaaa;
  text-decoration: none;
  margin-bottom: 5px;
  transition: color 0.3s;
}

.footer-link:hover {
  color: #6366f1;
}

.back-to-top {
  text-align: center;
  margin-top: 25px;
  padding-top: 20px;
  border-top: 1px solid #333333;
}

.top-arrow {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  transition: transform 0.3s;
}

.top-arrow:hover {
  transform: translateY(-3px);
}

@media (max-width: 768px) {
  .header {
    flex-direction: column;
    gap: 15px;
  }

  .hero-content h1 {
    font-size: 32px;
  }

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