:root {
    --unactive-scale: 1;
    --pre-active-scale: 1;
    --active-scale: 1.4;
    --line-radius: 100px;
    --card-radius: 20%;
    --left-color: #eba2ff;
    --right-color: #ffb639;
    --card-color: #ffffff3e;
    --left-color: #5bcffa;
    --right-color: #f5abb9;
    --transform-time: 2s;
    --nyancat-scale: 0.3;
    --progress-height: 50;
    --spark-time: 2800ms;
}

/* 对整个页面 body 隐藏滚动条，但仍可滚动 */
body {
    scrollbar-width: none;
    /* Firefox */
    -ms-overflow-style: none;
    /* IE 10+ */
    overflow-y: scroll;
    /* 保证滚动功能 */
}

/* Chrome, Edge, Safari */
body::-webkit-scrollbar {
    width: 0px;
    background: transparent;
    /* 可选：完全透明 */
}


html,
body {
    background:
        radial-gradient(farthest-side at top right, #ffffff 98%, #0000) calc(50% - 10px) 0/20px 20px no-repeat,
        radial-gradient(farthest-side at bottom right, #ffffff 98%, #0000) calc(50% - 10px) 100%/20px 20px no-repeat,
        linear-gradient(90deg, var(--left-color) 50%, var(--right-color) 0);
}

main {
    padding: 0px;
}

.t-item {
    display: flex;
    justify-content: center;
    margin-bottom: -20px;
    transition: height var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

/* 时间线 */

.t-line {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50%;
    border-width: 20px 20px 20px 20px;
    border-style: solid;
    border-color: #0000;
    border-radius: var(--line-radius);
    transition: border var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        width var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        height var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

.t-item.left .t-line {
    flex-direction: row;
    background: linear-gradient(var(--left-color) 0 0) content-box,
        linear-gradient(to right, #0000 50%, #ffffff 0) border-box;
}

.t-item.right .t-line {
    flex-direction: row-reverse;
    background: linear-gradient(var(--right-color) 0 0) content-box,
        linear-gradient(to left, #0000 50%, #ffffff 0) border-box;
}

.t-item.pre-active .t-line {
    width: 70%;
}

.t-item.active .t-line {
    width: 100%;
}

/* 卡片背景 */

.t-item.active .t-background {
    display: flex ;
    justify-content: center;
    align-items: center;
    position: relative;
    width: 100%;
    padding: 20% 10% 20% 10%;
    /* max-width: 100%; */
    border-radius: var(--card-radius);
    /* transform: scale(0.8); */
    /* background:
        linear-gradient(var(--card-color) 0 0) content-box; */
}



/* 卡片 */

.t-card {
    display: flex;
    flex-direction: column;
    justify-content: center;
    color: #000000;
    padding: 20px;
    position: relative;
}

.t-item.left .t-card {
    right: 12.5%;
    transform: scale(var(--unactive-scale));
    transition:
        transform var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        right var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        max-width var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        height var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

.t-item.right .t-card {
    left: 12.5%;
    transform: scale(var(--unactive-scale));
    transition:
        transform var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        left var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        max-width var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        height var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

.t-item.active .t-card {
    max-width: 200px;
    margin: 15%;
}

.t-item.pre-active .t-card {
    margin: 15%;
}

.t-item.active.left .t-card {
    right: 0%;
    transform: scale(var(--active-scale));
}

.t-item.active.right .t-card {
    left: 0%;
    transform: scale(var(--active-scale));
}

.t-item.pre-active.left .t-card {
    right: 12.5%;
    transform: scale(var(--pre-active-scale));
}

.t-item.pre-active.right .t-card {
    left: 12.5%;
    transform: scale(var(--pre-active-scale));
}

/* 时间点 */

.t-dot {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    flex: 0 0 18px;
    box-shadow: 0 0 0 4px #fff, 0 2px 8px rgba(0, 0, 0, 0.08);
    position: absolute;
    transition:
        top var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        left var(--transform-time) cubic-bezier(.19, 1, .22, 1),
        right var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

.t-item.left .t-dot {
    top: 40%;
    left: calc(113% + 0px);
    background: var(--left-color);
}

.t-item.right .t-dot {
    top: 40%;
    right: calc(113% + 0px);
    background: var(--right-color);
}

.t-item.left.pre-active .t-dot {
    top: 46%;
    left: calc(140% + 0px);
}

.t-item.right.pre-active .t-dot {
    top: 46%;
    right: calc(140% + 0px);
}

.t-item.left.active .t-dot {
    top: 49%;
    left: calc(113% + 0px);
}

.t-item.right.active .t-dot {
    top: 49%;
    right: calc(113% + 0px);
}

/* 时间 */

.t-item .t-year {
    position: absolute;
}

.t-item.left .t-year {
    top: 25%;
    left: calc(130% + 0px);
}

.t-item.right .t-year {
    top: 25%;
    right: calc(130% + 0px);
}

.t-item.left.pre-active .t-year {
    top: 35%;
    left: calc(160% + 0px);
}

.t-item.right.pre-active .t-year {
    top: 35%;
    right: calc(160% + 0px);
}

.t-item.active .t-year {
    position: relative;
    top: 0%;
    left: 0;
    right: 0;
}

/* 标题 */

.t-title {
    margin: 5px;
    font-size: 18px;
    font-weight: 700;
}

/* 内容 */

.t-content {
    margin: 5px;
    position: absolute;
    visibility: hidden;
    opacity: 0;
    font-size: 15px;
    font-weight: 500;
    transition: opacity var(--transform-time) cubic-bezier(.19, 1, .22, 1);
}

.t-item.active .t-content {
    position: relative;
    visibility: visible;
    opacity: 1;
}

/* 详情 */

.t-card a {
    display: none;
    text-align: end;
}

.t-item.active a {
    display: block;
}