* {
     box-sizing: border-box;
 }

 html,
 body {
     margin: 0;
     font-family: "Montserrat", sans-serif;
     background: #f3f3f3;
     color: #222;
     overflow-x: hidden;
 }

 .parallax {
     width: 100%;
     min-height: 45vh;
     background-image: url("assets/iiser-kolkata.jpg");
     background-size: cover;
     background-position: center center;
     background-attachment: fixed;
     position: relative;
 }

 .parallax::after {
     content: "";
     position: absolute;
     inset: 0;
     background: linear-gradient(to bottom, rgba(0, 0, 0, .15), rgba(0, 0, 0, .15));
 }

 @media (max-width: 768px) {
     .parallax {
         background-image: url("assets/iiser-kolkata-mobile.jpg");
         background-position: center center;
         background-size: cover;
         background-attachment: scroll;
     }
 }

 .timeline-section {
     padding: 4rem 1rem;
     text-align: center;
 }

 .timeline-section h2 {
     font-size: 2rem;
     margin-bottom: 2rem;
     color: #0a0a0a;
 }

 .timeline {
     max-width: 1100px;
     margin: 0 auto;
     padding: 2.5rem 1rem;
     position: relative;
     display: grid;
     grid-template-columns: repeat(4, 1fr);
     gap: 2rem;
 }

 .timeline::before {
     content: "";
     position: absolute;
     left: 0;
     right: 0;
     top: 50%;
     height: 2px;
     background: #bdbdbd;
     transform: translateY(-50%);
 }

 .timeline-item {
     position: relative;
     text-align: center;
     padding: 3.6rem 1rem 3rem;
 }

 .timeline-item h3 {
     margin: 0 0 2.2rem;
     font-size: 1.05rem;
     font-weight: 700;
 }

 .timeline-item .year {
     display: block;
     margin: 1.1rem 0 .2rem;
     font-weight: 800;
     color: #00897b;
 }

 .timeline-item .detail {
     margin: 0;
     font-style: italic;
     color: #555;
 }

 .timeline-item .dot {
     position: absolute;
     top: 50%;
     left: 50%;
     width: 14px;
     height: 14px;
     background: #0a8f7a;
     border-radius: 50%;
     transform: translate(-50%, -50%);
     box-shadow: 0 0 0 3px rgba(10, 143, 122, 0.12);
 }

 @media (max-width: 900px) {
     .timeline {
         display: block;
         padding: 2rem 0;
     }

     .timeline::before {
         top: 0;
         left: 50%;
         transform: translateX(-50%);
         width: 2px;
         height: 100%;
     }

     .timeline-item {
         padding: 2.4rem 1rem 2.2rem;
         max-width: 480px;
         margin: 0 auto 2rem;
     }

     .timeline-item .dot {
         left: 50%;
         top: 50%;
         transform: translate(-50%, -50%);
     }
 }

 .achievements {
     background: var(--white);
     padding: 3.5rem 1rem;
 }

 .achievements h2 {
     text-align: center;
     margin: 0 0 1.8rem;
     font-size: 1.9rem;
 }

 .achievements ul {
     list-style: none;
     padding: 0;
     margin: 0 auto;
     max-width: 900px;
 }

 .achievements li {
     background: var(--bg-color);
     margin: .9rem 0;
     padding: 1rem 1.2rem;
     border-left: 5px solid #00897b;
     border-radius: 8px;
     line-height: 1.6;
     font-size: 1.03rem;
 }