body {
     font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
     margin: 0;
     padding: 20px;
     background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
     min-height: 100vh;
 }

 .container {
     max-width: 1200px;
     margin: 0 auto;
     background: white;
     border-radius: 20px;
     padding: 30px;
     box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
 }

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

 .header h1 {
     color: #2c3e50;
     margin-bottom: 10px;
     font-size: 2.5em;
 }

 .header p {
     color: #7f8c8d;
     font-size: 1.1em;
 }

 .roadmap-grid {
     display: grid;
     grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
     gap: 25px;
     margin-bottom: 40px;
 }

 .concept-card {
     background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
     border-radius: 15px;
     padding: 25px;
     color: white;
     position: relative;
     overflow: hidden;
     transition: transform 0.3s ease, box-shadow 0.3s ease;
 }

 .concept-card:hover {
     transform: translateY(-5px);
     box-shadow: 0 15px 30px rgba(0, 0, 0, 0.2);
 }

 .concept-card.ai-basic {
     background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
 }

 .concept-card.ml-basic {
     background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
 }

 .concept-card.dl-basic {
     background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
 }

 .concept-card.tools {
     background: linear-gradient(135deg, #a8edea 0%, #fed6e3 100%);
     color: #2c3e50;
 }

 .concept-card h3 {
     margin-top: 0;
     font-size: 1.4em;
     margin-bottom: 15px;
     display: flex;
     align-items: center;
 }

 .concept-card .icon {
     font-size: 1.8em;
     margin-right: 10px;
 }

 .concept-list {
     list-style: none;
     padding: 0;
     margin: 0;
 }

 .concept-item {
     margin: 8px 0;
     border-radius: 8px;
     overflow: hidden;
     background: rgba(255, 255, 255, 0.1);
     transition: all 0.3s ease;
 }

 .concept-header {
     padding: 12px 15px;
     cursor: pointer;
     display: flex;
     align-items: center;
     justify-content: space-between;
     user-select: none;
     transition: background-color 0.3s ease;
 }

 .concept-header:hover {
     background: rgba(255, 255, 255, 0.1);
 }

 .concept-title {
     font-weight: 600;
     font-size: 0.95em;
 }

 .expand-icon {
     transition: transform 0.3s ease;
     font-size: 1.1em;
 }

 .concept-item.expanded .expand-icon {
     transform: rotate(90deg);
 }

 .concept-content {
     max-height: 0;
     overflow: hidden;
     transition: max-height 0.3s ease;
     background: rgba(0, 0, 0, 0.1);
 }

 .concept-item.expanded .concept-content {
     max-height: 200px;
 }

 .concept-details {
     padding: 15px;
     font-size: 0.9em;
     line-height: 1.5;
 }

 .concept-details ul {
     margin: 8px 0;
     padding-left: 20px;
 }

 .concept-details li {
     margin: 5px 0;
 }

 .tools .concept-header {
     color: #2c3e50;
 }

 .tools .concept-details {
     color: #34495e;
 }

 .warning-section {
     background: linear-gradient(135deg, #ff6b6b 0%, #ee5a24 100%);
     color: white;
     padding: 30px;
     border-radius: 15px;
     margin: 30px 0;
     position: relative;
     overflow: hidden;
 }

 .warning-section::before {
     content: "⚠️";
     font-size: 3em;
     position: absolute;
     right: 20px;
     top: 20px;
     opacity: 0.3;
 }

 .warning-section h2 {
     margin-top: 0;
     font-size: 1.8em;
     margin-bottom: 20px;
 }

 .warning-grid {
     display: grid;
     grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
     gap: 20px;
 }

 .warning-card {
     background: rgba(255, 255, 255, 0.1);
     padding: 20px;
     border-radius: 10px;
     border-left: 4px solid #fff;
 }

 .warning-card h4 {
     margin-top: 0;
     color: #fff;
     display: flex;
     align-items: center;
 }

 .warning-card .warning-icon {
     margin-right: 8px;
     font-size: 1.2em;
 }

 .best-practices {
     background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
     color: white;
     padding: 30px;
     border-radius: 15px;
     margin: 30px 0;
 }

 .best-practices h2 {
     margin-top: 0;
     display: flex;
     align-items: center;
 }

 .best-practices .icon {
     margin-right: 10px;
     font-size: 1.5em;
 }

 .practice-grid {
     display: grid;
     grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
     gap: 15px;
     margin-top: 20px;
 }

 .practice-item {
     background: rgba(255, 255, 255, 0.1);
     padding: 15px;
     border-radius: 8px;
     display: flex;
     align-items: flex-start;
 }

 .practice-item .check {
     color: #fff;
     margin-right: 10px;
     font-size: 1.2em;
     margin-top: 2px;
 }

 .flow-arrows {
     display: flex;
     justify-content: center;
     margin: 20px 0;
 }

 .arrow {
     font-size: 2em;
     color: #7f8c8d;
     margin: 0 10px;
     animation: bounce 2s infinite;
 }

 @keyframes bounce {

     0%,
     20%,
     50%,
     80%,
     100% {
         transform: translateY(0);
     }

     40% {
         transform: translateY(-10px);
     }

     60% {
         transform: translateY(-5px);
     }
 }

 .progress-bar {
     background: #ecf0f1;
     height: 8px;
     border-radius: 4px;
     margin: 15px 0;
     overflow: hidden;
 }

 .progress-fill {
     height: 100%;
     background: linear-gradient(90deg, #4facfe 0%, #00f2fe 100%);
     border-radius: 4px;
     animation: progress 3s ease-out;
 }

 @keyframes progress {
     0% {
         width: 0%;
     }

     100% {
         width: 100%;
     }
 }

 .footer {
     text-align: center;
     margin-top: 40px;
     color: #7f8c8d;
     font-style: italic;
 }

 @media (max-width: 768px) {
     .container {
         padding: 20px;
     }

     .header h1 {
         font-size: 2em;
     }

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