.navigation button:focus { outline: none }    
.lc_k{ max-width:1200px;  width:94%; margin:0 auto;height: auto; position: relative; }

@media (min-width: 1930px) {
.lc_k{ max-width: 1600px; width:94%; margin:0 auto;}
}

.timeline-container {
    position: relative;
    width: 100%;
    padding: 0px 0 10px; 
}

/* 时间线 */
.timeline-line {
    position: absolute;
    top: 19px;
    left: 50px;
    right: 50px;
    height: 6px;
    background: rgba(0, 0, 0, 0.2);
    border-radius: 3px;
    z-index: 1;
}

.timeline-progress {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 20%;
    background: linear-gradient(to right, #1b7acb, #0cb2f9);
    border-radius: 3px;
    transition: width 0.5s ease;
    z-index: 2;
}

/* 时间点 */
.timeline-items {
    display: flex;
    justify-content: space-between;
    position: relative;
    z-index: 3;
    padding: 0 50px;
}

.timeline-item {
    position: relative;
    text-align: center;
    cursor: pointer;
    flex: 1;
    max-width: 200px;
    transition: all 0.3s ease;
}

.timeline-item::before {
    content: '';
    position: absolute;
    top: -30px;
    left: 50%;
    transform: translateX(-50%);
    width: 15px;
    height: 15px;
    border-radius: 50%;
    background: #ffffff;
    border: 4px solid  rgba(0, 0, 0, 0.2);
    transition: all 0.3s ease;
    transition: all 0.3s ease;
    z-index: 4;
}

.timeline-item.active::before {
    background: #1b7acb;
    border-color: #fff;
    box-shadow: 0 0 0 8px rgba(95, 194, 255, 0.3);
}

.timeline-item .year {
    font-size:20px;
    font-weight: 700;
    margin-top: 10px;
    color: #222;
}

.timeline-item.active .year {
    color: #0282d2;
    transform: scale(1.2);
}


/* 内容区域 */
.content-container {
    position: relative; height: 100%;
    margin-top: 20px;
    padding: 0 50px;
}

.content-item {
    position: relative;
    width: 100%;
    border-radius: 10px;
    padding: 30px;
    background: #fff;
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.05);
    display: none;
    opacity: 0; border: 1px solid #e8eef2;;
    transform: translateY(20px);
    transition: opacity 0.5s ease, transform 0.5s ease;
}

.content-item.active {
    display: block;
    opacity: 1;
    transform: translateY(0);
    animation: fadeIn 0.8s ease;
}

@keyframes fadeIn {
    from {
opacity: 0;
transform: translateY(20px);
    }
    to {
opacity: 1;
transform: translateY(0);
    }
}



.content-item .lc_info{
    font-size: 16px;
    line-height: 200%;
    color: #7a879c;
}

.milestones {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-top: 30px;
}

.milestone {
    flex: 1;
    min-width: 200px;
    background: rgba(255, 255, 255, 0.1);
    padding: 20px;
    border-radius: 12px;
    border-left: 4px solid #1b7acb;
}

     

/* 移动端适配 */
 @media (max-width: 1300px) { .content-item .lc_info{font-size: 14px;}}

 @media (max-width: 992px) {
.timeline-items {
overflow-x: auto;
padding: 40px 10px 10px 10px;
justify-content: flex-start;
scrollbar-width: none;
    }
 
   .timeline-line {
    position: absolute;
    top:19px;
    left: 40px;
    right: 40px;

}
.timeline-item {
min-width: 150px;
padding: 0 15px;
    }
    
.content-container {
padding: 0 20px;
    }

  .timeline-container {
    position: relative;
    width: 100%;
    padding: 0px 0 30px;
}

.timeline-item .year { font-size:18px;}

}




@media (max-width: 576px) {
    .content-item{
padding: 30px 20px;
    }
    .timeline-item .year { font-size:16px;}

    .milestones {
flex-direction: column;
    }
}



.navigation {
    display: flex;
    justify-content:space-between;
   align-items: center;
    margin-top:0; z-index: 10; position: relative;
}

.nav-btn {
    background: #b7b7b7;
    border: none;
    color: #fff;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    font-size:14px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center; 
}
     .nav-btn i{font-size: 14px;}

@media (max-width: 992px) {
.nav-btn {  width: 32px; height: 32px;}
.navigation { margin-top: 0px; position: absolute;width: 100%; height: 40px;top:0;left:0}
 }


@media (max-width: 576px) {
    .nav-btn {  width: 30px; height: 30px;}

}

.nav-btn:hover {
    background: #1b7acb;
    transform: translateY(-3px);
    box-shadow: 0 5px 15px rgba(95, 175, 255, 0.4);
}