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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  background: #f8f9fa;
  min-height: 100vh;
  overflow-x: hidden;
  line-height: 1.6;
}

html {
  scroll-behavior: smooth;
}

/* ================== HEADER ================== */
.landing-header {
  background: rgba(255, 255, 255, 0.98);
  padding: 15px 0;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 1000;
  backdrop-filter: blur(10px);
}

.landing-nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 30px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.logo {
  font-size: 24px;
  font-weight: 700;
  color: #0066cc;
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-links {
  display: flex;
  gap: 30px;
  align-items: center;
}

.nav-links a {
  text-decoration: none;
  color: #333;
  font-weight: 500;
  font-size: 14px;
  transition: color 0.3s;
  position: relative;
}

.nav-links a:hover {
  color: #0066cc;
}

.btn-login {
  background: #0066cc;
  color: white;
  padding: 10px 25px;
  border-radius: 25px;
  border: none;
  cursor: pointer;
  font-weight: 600;
  font-size: 14px;
  transition: all 0.3s;
}

.btn-login:hover {
  background: #0052a3;
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(0,102,204,0.3);
}

.mobile-menu-btn {
  display: none;
  font-size: 24px;
  cursor: pointer;
  color: #333;
}

/* ================== HERO SECTION ================== */
.hero-section {
  background: linear-gradient(135deg, #0066cc 0%, #004c99 100%);
  color: white;
  padding: 80px 30px 60px;
}

.hero-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-text h1 {
  font-size: 48px;
  margin-bottom: 20px;
  line-height: 1.2;
}

.hero-text p {
  font-size: 18px;
  margin-bottom: 30px;
  opacity: 0.95;
  line-height: 1.6;
}

.hero-buttons {
  display: flex;
  gap: 15px;
  flex-wrap: wrap;
}

.btn-primary {
  background: white;
  color: #0066cc;
  padding: 15px 35px;
  border: none;
  border-radius: 25px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255,255,255,0.3);
}

.btn-secondary {
  background: transparent;
  color: white;
  padding: 15px 35px;
  border: 2px solid white;
  border-radius: 25px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
}

.btn-secondary:hover {
  background: white;
  color: #0066cc;
}

.hero-image {
  text-align: center;
}

.hero-image img {
  max-width: 100%;
  height: auto;
  border-radius: 15px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.warning-note {
  background: #fff9e6;
  border-left: 4px solid #ffc107;
  padding: 20px;
  margin: 40px auto 0;
  max-width: 1200px;
  border-radius: 8px;
  color: #856404;
}

.warning-note strong {
  display: block;
  margin-bottom: 10px;
  font-size: 16px;
}

/* ================== SECTIONS ================== */
.content-section {
  background: white;
  padding: 80px 30px;
}

.section-title {
  font-size: 36px;
  color: #333;
  margin-bottom: 15px;
  text-align: center;
}

.section-subtitle {
  text-align: center;
  color: #666;
  margin-bottom: 50px;
  font-size: 18px;
}

.section-content {
  max-width: 1200px;
  margin: 0 auto;
}

/* ================== INFO CARDS ================== */
.info-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 30px;
  max-width: 1200px;
  margin: 0 auto;
}

.info-card {
  background: white;
  padding: 30px;
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.08);
  transition: all 0.3s;
  border: 2px solid #f0f0f0;
}

.info-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 25px rgba(0,102,204,0.15);
  border-color: #0066cc;
}

.card-icon {
  font-size: 48px;
  margin-bottom: 15px;
  display: block;
}

.info-card h3 {
  color: #0066cc;
  margin-bottom: 15px;
  font-size: 22px;
}

.info-card p {
  color: #555;
  line-height: 1.7;
  font-size: 15px;
}

/* ================== IMAGE WITH LINK ================== */
.image-link-card {
  position: relative;
  overflow: hidden;
  border-radius: 15px;
  cursor: pointer;
  transition: all 0.3s;
}

.image-link-card img {
  width: 100%;
  height: 250px;
  object-fit: cover;
  transition: transform 0.3s;
}

.image-link-card:hover img {
  transform: scale(1.05);
}

.image-link-card .overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: linear-gradient(to top, rgba(0,0,0,0.8), transparent);
  padding: 20px;
  color: white;
}

.image-link-card .overlay h4 {
  font-size: 18px;
  margin-bottom: 5px;
}

.image-link-card .overlay p {
  font-size: 14px;
  opacity: 0.9;
}

/* ================== PREDICTION SECTION ================== */
.prediction-section {
  background: #f8f9fa;
  padding: 80px 30px;
}

.upload-container {
  max-width: 700px;
  margin: 0 auto;
  background: white;
  padding: 40px;
  border-radius: 15px;
  box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}

.upload-area {
  border: 3px dashed #0066cc;
  border-radius: 12px;
  padding: 40px 30px;
  text-align: center;
  margin: 20px 0;
  cursor: pointer;
  transition: all 0.3s;
  background: #f8f9ff;
}

.upload-area:hover {
  background: #e6f0ff;
  border-color: #0052a3;
}

.upload-icon {
  font-size: 48px;
  margin-bottom: 10px;
}

.upload-area p {
  font-size: 16px;
  color: #333;
  margin-bottom: 5px;
}

.upload-hint {
  font-size: 14px;
  color: #999;
}

.file-input {
  display: none;
}

.file-list {
  margin-top: 20px;
  padding: 15px;
  background: #f8f9fa;
  border-radius: 10px;
}

.file-item {
  padding: 10px;
  margin: 5px 0;
  background: white;
  border-radius: 8px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.btn-predict {
  background: #0066cc;
  color: white;
  padding: 15px 40px;
  border: none;
  border-radius: 25px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  margin-top: 20px;
  transition: all 0.3s;
}

.btn-predict:hover {
  background: #0052a3;
  transform: translateY(-2px);
}

.btn-predict:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.prediction-result {
  margin-top: 30px;
  padding: 25px;
  background: #f8f9fa;
  border-radius: 12px;
  display: none;
}

.prediction-result.active {
  display: block;
}

.result-header {
  text-align: center;
  margin-bottom: 20px;
  padding-bottom: 15px;
  border-bottom: 2px solid #e0e0e0;
}

.result-status {
  font-size: 28px;
  font-weight: bold;
  color: #0066cc;
  margin: 10px 0;
}

.result-details {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin-bottom: 15px;
}

.result-item {
  background: white;
  padding: 15px;
  border-radius: 8px;
}

.result-label {
  display: block;
  font-weight: 600;
  color: #0066cc;
  font-size: 13px;
  margin-bottom: 5px;
}

.result-value {
  font-size: 18px;
  color: #333;
  font-weight: 600;
}

/* ================== CONTACT SECTION ================== */
.contact-section {
  background: #2c3e50;
  color: white;
  padding: 80px 30px;
}

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

.contact-info {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 30px;
  margin-bottom: 60px;
}

.contact-card {
  background: rgba(255,255,255,0.1);
  padding: 30px;
  border-radius: 15px;
  text-align: center;
  transition: all 0.3s;
}

.contact-card:hover {
  background: rgba(255,255,255,0.15);
  transform: translateY(-5px);
}

.contact-icon {
  font-size: 40px;
  margin-bottom: 15px;
}

.social-links {
  margin: 60px 0;
  text-align: center;
}

.social-links h3 {
  font-size: 24px;
  margin-bottom: 30px;
}

.social-icons {
  display: flex;
  justify-content: center;
  gap: 20px;
  flex-wrap: wrap;
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 15px 25px;
  background: rgba(255,255,255,0.1);
  border-radius: 30px;
  text-decoration: none;
  color: white;
  transition: all 0.3s;
  border: 2px solid transparent;
}

.social-link:hover {
  background: rgba(255,255,255,0.2);
  border-color: white;
  transform: translateY(-3px);
}

.social-link img {
  width: 24px;
  height: 24px;
  filter: brightness(0) invert(1);
}

.team-section {
  margin-top: 60px;
}

.team-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 30px;
  margin-top: 40px;
}

.team-member {
  background: rgba(255,255,255,0.1);
  padding: 30px;
  border-radius: 15px;
  text-align: center;
  transition: all 0.3s;
}

.team-member:hover {
  background: rgba(255,255,255,0.15);
  transform: translateY(-5px);
}

.member-avatar {
  width: 120px;
  height: 120px;
  margin: 0 auto 20px;
  border-radius: 50%;
  overflow: hidden;
  border: 4px solid rgba(255,255,255,0.3);
  cursor: pointer;
  transition: transform 0.3s;
}

.member-avatar:hover {
  transform: scale(1.05);
}

.member-avatar img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.member-social {
  display: flex;
  justify-content: center;
  gap: 10px;
  margin-top: 15px;
}

.member-social a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: rgba(255,255,255,0.2);
  border-radius: 50%;
  transition: all 0.3s;
}

.member-social a:hover {
  background: white;
  transform: scale(1.1);
}

.member-social img {
  width: 18px;
  height: 18px;
  filter: brightness(0) invert(1);
}

.member-social a:hover img {
  filter: none;
}

/* ================== FOOTER ================== */
.footer {
  background: #1a1a1a;
  color: white;
  padding: 40px 30px 20px;
}

.footer-content {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 40px;
  margin-bottom: 30px;
}

.footer-column h4 {
  margin-bottom: 15px;
  font-size: 18px;
  color: #0066cc;
}

.footer-column a {
  display: block;
  color: rgba(255,255,255,0.7);
  text-decoration: none;
  margin-bottom: 10px;
  font-size: 14px;
  transition: color 0.3s;
}

.footer-column a:hover {
  color: #0066cc;
}

.footer-bottom {
  text-align: center;
  padding-top: 20px;
  border-top: 1px solid rgba(255,255,255,0.1);
  color: rgba(255,255,255,0.5);
  font-size: 14px;
}

/* ================== MODAL ================== */
.modal {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0,0,0,0.7);
  z-index: 2000;
  justify-content: center;
  align-items: center;
}

.modal.active {
  display: flex;
}

.modal-content {
  background: white;
  padding: 40px;
  border-radius: 20px;
  max-width: 550px;
  width: 90%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
  padding-bottom: 15px;
  border-bottom: 2px solid #e0e0e0;
}

.modal-header h2 {
  color: #0066cc;
  font-size: 26px;
}

.close-modal {
  background: none;
  border: none;
  font-size: 28px;
  cursor: pointer;
  color: #999;
  transition: color 0.3s;
}

.close-modal:hover {
  color: #333;
}

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

.form-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 15px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  color: #333;
  font-weight: 600;
  font-size: 14px;
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: 12px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 14px;
  transition: border-color 0.3s;
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  outline: none;
  border-color: #0066cc;
}

.btn-submit {
  background: #0066cc;
  color: white;
  padding: 14px 30px;
  border: none;
  border-radius: 25px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  transition: all 0.3s;
  margin-top: 10px;
}

.btn-submit:hover {
  background: #0052a3;
  transform: translateY(-2px);
}

.form-toggle {
  text-align: center;
  margin-top: 20px;
  color: #666;
  font-size: 14px;
}

.form-toggle a {
  color: #0066cc;
  cursor: pointer;
  text-decoration: none;
  font-weight: 600;
}

/* ================== DASHBOARD ================== */
.dashboard {
  display: none;
  min-height: 100vh;
}

.dashboard.active {
  display: flex;
}

.sidebar {
  width: 280px;
  background: #2c3e50;
  color: white;
  padding: 20px;
  display: flex;
  flex-direction: column;
  box-shadow: 2px 0 10px rgba(0,0,0,0.1);
}

.sidebar-header {
  margin-bottom: 30px;
  padding-bottom: 20px;
  border-bottom: 1px solid rgba(255,255,255,0.1);
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 50px;
  height: 50px;
  background: #0066cc;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  font-weight: bold;
}

.user-details h3 {
  font-size: 16px;
  margin-bottom: 4px;
}

.user-details p {
  font-size: 12px;
  opacity: 0.7;
}

.menu-item {
  padding: 15px 20px;
  margin-bottom: 8px;
  border-radius: 10px;
  cursor: pointer;
  transition: all 0.3s;
  display: flex;
  align-items: center;
  gap: 12px;
}

.menu-item:hover {
  background: rgba(255,255,255,0.1);
}

.menu-item.active {
  background: #0066cc;
}

.btn-logout {
  background: #e74c3c;
  color: white;
  padding: 12px 20px;
  border: none;
  border-radius: 10px;
  cursor: pointer;
  margin-top: auto;
  font-weight: 600;
  transition: all 0.3s;
}

.btn-logout:hover {
  background: #c0392b;
}

.dashboard-main {
  flex: 1;
  padding: 30px;
  overflow-y: auto;
  background: #f8f9fa;
}

.dashboard-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 30px;
}

.dashboard-title {
  font-size: 28px;
  color: #333;
}

.status-badge {
  background: #0066cc;
  color: white;
  padding: 8px 20px;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
}

.dashboard-section {
  display: none;
}

.dashboard-section.active {
  display: block;
}

.card {
  background: white;
  padding: 25px;
  border-radius: 12px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.08);
  margin-bottom: 25px;
}

.card h3 {
  color: #0066cc;
  margin-bottom: 20px;
  font-size: 20px;
}

.info-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
}

.info-item {
  padding: 15px;
  background: #f8f9fa;
  border-radius: 8px;
}

.info-label {
  font-size: 13px;
  color: #666;
  margin-bottom: 5px;
}

.info-value {
  font-size: 16px;
  color: #333;
  font-weight: 600;
}

.tag {
  padding: 6px 15px;
  border-radius: 20px;
  font-size: 13px;
  font-weight: 600;
}

.tag-abnormal {
  background: #fee;
  color: #e74c3c;
}

.ecg-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
}

.ecg-lead {
  background: #f8f9fa;
  padding: 15px;
  border-radius: 8px;
}

.ecg-lead-title {
  font-weight: 600;
  margin-bottom: 10px;
  color: #0066cc;
}

.ecg-placeholder {
  height: 150px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #999;
  border: 2px dashed #ddd;
  border-radius: 8px;
}

.empty-state {
  text-align: center;
  padding: 40px;
  color: #999;
}

.empty-state-icon {
  font-size: 64px;
  margin-bottom: 15px;
}

/* ================== RESPONSIVE ================== */
@media (max-width: 768px) {
  .hero-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-text h1 {
    font-size: 36px;
  }

  .nav-links {
    display: none;
  }

  .mobile-menu-btn {
    display: block;
  }

  .info-grid,
  .contact-info,
  .team-grid {
    grid-template-columns: 1fr;
  }

  .sidebar {
    width: 100%;
    max-width: 280px;
  }

  .dashboard {
    flex-direction: column;
  }

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