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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f8f9fa;
  line-height: 1.6;
  color: #333;
}

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

/* Header Styles */
.header {
  background: linear-gradient(135deg, #2c5aa0 0%, #1e3a8a 100%);
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
  transition: transform 0.3s ease;
}

.header-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 0;
  gap: 30px;
}

.logo img {
  width: 60px;
  height: 60px;
  border-radius: 10px;
  cursor: pointer;
  object-fit: cover;
  border: none;
}

.nav {
  display: flex;
  align-items: center;
  gap: 15px;
  flex: 1;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.download-btn {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(16, 185, 129, 0.3);
  white-space: nowrap;
}

.download-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

.nav-subtitle {
  font-size: 10px;
  color: #cbd5e1;
  margin-top: 2px;
}

.nav-dropdown {
  position: relative;
  width: 110px;
}

.nav-link {
  white-space: nowrap;
  color: white;
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  cursor: pointer;
  padding: 8px 12px;
  border-radius: 20px;
  transition: all 0.3s ease;
  display: block;
}

.nav-link:hover {
  background: rgba(255,255,255,0.15);
  transform: translateY(-1px);
}

.dropdown-content {
  position: absolute;
  top: 100%;
  left: 0;
  background: white;
  min-width: 160px;
  box-shadow: 0 8px 25px rgba(0,0,0,0.15);
  border-radius: 8px; /* Giữ border-radius cố định */
  opacity: 0;
  visibility: hidden;
  transform: translateY(-10px);
  transition: all 0.3s ease;
  z-index: 1000;
  overflow: hidden;
  font-weight: bold;
}

.nav-dropdown:hover .dropdown-content {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.dropdown-content a {
  display: block;
  padding: 10px 15px;
  color: #374151;
  text-decoration: none;
  font-size: 12px;
  transition: all 0.2s ease;
}

.dropdown-content a:hover {
  background: #f3f4f6;
  color: #10b981;
}

.user-area {
  display: flex;
  align-items: center;
  gap: 10px;
  min-width: max-content; /* Thêm dòng này */
}

.auth-btn {
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  white-space: nowrap;
  flex-shrink: 0; /* Quan trọng: ngăn không cho nút co lại */
  min-width: max-content; /* Đảm bảo nút không bị thu nhỏ */
}
.login-btn {
  background: linear-gradient(135deg, #2563eb 0%, #1e40af 100%);
  box-shadow: 0 2px 8px rgb(37, 99, 235);
}

.login-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgb(59, 130, 246);
}

.logged-btn {
  background: linear-gradient(135deg, #ff3535 0%, #fd1515 100%);
  box-shadow: 0 2px 8px rgb(248, 30, 30);
}

.logged-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgb(255, 61, 61);
}

.register-btn {
  background: linear-gradient(135deg, #7c3aed 0%, #6d28d9 100%);
  box-shadow: 0 2px 8px rgb(124, 58, 237);
}

.register-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgb(139, 92, 246);
}

.game-btn {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  padding: 8px 16px;
  border-radius: 20px;
  font-weight: 600;
  font-size: 12px;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 2px 8px rgba(22, 255, 177, 0.918);
  white-space: nowrap;
}

.game-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

/* Modal Styles */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(5px);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
}

.modal-overlay.active {
  opacity: 1;
  visibility: visible;
}

.modal-content {
  background: white;
  border-radius: 16px;
  padding: 0;
  width: 90%;
  max-width: 400px;
  box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
  transform: scale(0.8) translateY(-50px);
  transition: all 0.3s ease;
}

.modal-overlay.active .modal-content {
  transform: scale(1) translateY(0);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 20px 25px;
  border-bottom: 1px solid #e5e7eb;
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  border-radius: 16px 16px 0 0;
}

.modal-header h2 {
  color: white;
  font-size: 20px;
  font-weight: 600;
}

.close-btn {
  background: none;
  border: none;
  color: white;
  font-size: 24px;
  cursor: pointer;
  padding: 0;
  width: 30px;
  height: 30px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  transition: all 0.2s ease;
}

.close-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

.login-form,
.register-form {
  padding: 25px;
}

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

.form-group label {
  display: block;
  margin-bottom: 5px;
  font-weight: 500;
  color: #374151;
}

.form-group input {
  width: 100%;
  padding: 12px 15px;
  border: 2px solid #e5e7eb;
  border-radius: 8px;
  font-size: 14px;
  transition: all 0.3s ease;
}

.form-group input:focus {
  outline: none;
  border-color: #10b981;
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.form-options {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 25px;
  flex-wrap: wrap;
  gap: 10px;
}

.checkbox-label {
  display: flex;
  align-items: center;
  cursor: pointer;
  font-size: 14px;
  color: #6b7280;
}

.checkbox-label input[type="checkbox"] {
  margin-right: 8px;
  width: auto;
}

.forgot-password {
  color: #10b981;
  text-decoration: none;
  font-size: 14px;
  transition: color 0.2s ease;
}

.forgot-password:hover {
  color: #059669;
}

.submit-btn {
  width: 100%;
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  padding: 12px;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.submit-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.modal-footer {
  padding: 20px 25px;
  text-align: center;
  border-top: 1px solid #e5e7eb;
  background: #f9fafb;
  border-radius: 0 0 16px 16px;
}

.modal-footer p {
  color: #6b7280;
  font-size: 14px;
}

.modal-footer a {
  color: #10b981;
  text-decoration: none;
  font-weight: 500;
}

.modal-footer a:hover {
  color: #059669;
}

/* Hero Section */
.hero {
  padding: 30px 0;
}

.nso-brand {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 20px;
}

.brand-dot {
  font-size: 20px;
}

.brand-text {
  font-size: 24px;
  font-weight: 700;
  color: #1f2937;
}

.brand-subtitle {
  color: #6b7280;
  font-size: 14px;
}

.hero-banner {
  position: relative;
  border-radius: 16px;
  overflow: hidden;
  box-shadow: 0 10px 30px rgba(0,0,0,0.1);
  background: linear-gradient(135deg, #1e3a8a 0%, #7c3aed 100%);
}

.banner-slider {
  position: relative;
  height: 350px;
}

.slide {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  transition: all 0.8s cubic-bezier(0.4, 0, 0.2, 1);
  transform: translateX(100%);
}

.slide.active {
  opacity: 1;
  transform: translateX(0);
}

.slide.prev {
  transform: translateX(-100%);
}

.banner-bg {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.3;
}

.banner-overlay {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  text-align: center;
  padding: 40px;
}

.banner-title {
  color: white;
  font-size: 32px;
  font-weight: 700;
  margin-bottom: 30px;
  text-shadow: 2px 2px 4px rgba(0,0,0,0.5);
  animation: fadeInUp 0.8s ease-out;
}

.banner-rewards {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
  animation: fadeInUp 0.8s ease-out 0.2s both;
}

.reward-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  background: rgba(255,255,255,0.1);
  padding: 15px;
  border-radius: 12px;
  backdrop-filter: blur(10px);
  border: 1px solid rgba(255,255,255,0.2);
  transition: all 0.3s ease;
}

.reward-item:hover {
  transform: translateY(-5px) scale(1.05);
  background: rgba(255,255,255,0.2);
}

.reward-item img {
  width: 60px;
  height: 60px;
  border-radius: 8px;
  object-fit: cover;
}

.reward-item span {
  color: white;
  font-size: 11px;
  text-align: center;
  font-weight: 500;
  text-shadow: 1px 1px 2px rgba(0,0,0,0.5);
}

/* Slider Navigation */
.slider-nav {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
}

.nav-dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.5);
  background: transparent;
  cursor: pointer;
  transition: all 0.3s ease;
}

.nav-dot.active {
  background: white;
  border-color: white;
}

.nav-dot:hover {
  border-color: white;
  transform: scale(1.2);
}

/* Slider Arrows */
.slider-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  background: rgba(255, 255, 255, 0.2);
  border: none;
  color: white;
  font-size: 20px;
  width: 50px;
  height: 50px;
  border-radius: 50%;
  cursor: pointer;
  transition: all 0.3s ease;
  backdrop-filter: blur(10px);
}

.slider-arrow:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: translateY(-50%) scale(1.1);
}

.prev-arrow {
  left: 20px;
}

.next-arrow {
  right: 20px;
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

/* News Section */
.news {
  padding: 40px 0;
}

.news-header {
  text-align: center;
  margin-bottom: 40px;
}

.news-title {
  font-size: 28px;
  font-weight: 700;
  color: #1f2937;
  margin-bottom: 8px;
}

.news-subtitle {
  color: #6b7280;
  font-size: 16px;
  margin-bottom: 20px;
}

.news-categories {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.category {
  padding: 8px 16px;
  border-radius: 20px;
  font-size: 14px;
  cursor: pointer;
  transition: all 0.3s ease;
  border: 1px solid #e5e7eb;
}

.category.active {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border-color: #10b981;
}

.category:not(.active):hover {
  background: #f3f4f6;
  border-color: #10b981;
  color: #10b981;
}

.news-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
  gap: 25px;
  margin-bottom: 40px;
}

.news-card {
  background: white;
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
  transition: all 0.3s ease;
  border: 1px solid #f1f5f9;
}

.news-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,0,0,0.12);
}

.card-image {
  position: relative;
}

.card-image img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.card-content {
  padding: 20px;
}

.card-title {
  font-size: 16px;
  font-weight: 600;
  color: #1f2937;
  margin-bottom: 10px;
  line-height: 1.5;
}

.card-description {
  color: #6b7280;
  font-size: 14px;
  line-height: 1.6;
  margin-bottom: 15px;
}

.card-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-date {
  font-size: 12px;
  color: #9ca3af;
}

.read-more-btn {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  padding: 6px 12px;
  border-radius: 15px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
}

.read-more-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px #059669;
}

.load-more {
  text-align: center;
}

.load-more-btn {
  background: linear-gradient(135deg, #10b981 0%, #059669 100%);
  color: white;
  border: none;
  padding: 12px 30px;
  border-radius: 25px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 4px 15px rgba(16, 185, 129, 0.3);
}

.load-more-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

/* Responsive Design */
@media (max-width: 768px) {
  .header-content {
    flex-direction: column;
    gap: 15px;
  }
  
  .nav {
    order: 2;
    flex-wrap: wrap;
    justify-content: center;
    gap: 15px;
  }
  
  .user-area {
    order: 1;
  }
  
  .banner-title {
    font-size: 24px;
  }
  
  .banner-rewards {
    gap: 10px;
  }
  
  .reward-item {
    padding: 10px;
  }
  
  .reward-item img {
    width: 40px;
    height: 40px;
  }
  
  .reward-item span {
    font-size: 10px;
  }
  
  .news-grid {
    grid-template-columns: 1fr;
    gap: 20px;
  }
  
  .news-categories {
    gap: 10px;
  }
  
  .slider-arrow {
    width: 40px;
    height: 40px;
    font-size: 16px;
  }
  
  .prev-arrow {
    left: 10px;
  }
  
  .next-arrow {
    right: 10px;
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 15px;
  }
  
  .banner-title {
    font-size: 20px;
  }
  
  .banner-rewards {
    flex-direction: column;
    align-items: center;
  }
  
  .card-content {
    padding: 15px;
  }
  
  .modal-content {
    width: 95%;
    margin: 20px;
  }
  
  .user-area {
    flex-wrap: wrap;
    gap: 8px;
  }
  
  .auth-btn {
    font-size: 11px;
    padding: 6px 12px;
    white-space: nowrap;
  }
}