* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Arial', sans-serif;
}

body {
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.6;
    overflow-x: hidden;
}

.bg {
    position: fixed;
    background-repeat: no-repeat;
    background-size: cover;
    height: 100vh;
    width: 100vw;
    background-image: url("https://static.igem.wiki/teams/5370/title/parts.png");
    z-index: -2;
}

.bg-filter {
    position: fixed;
    background-repeat: no-repeat;
    background-size: cover;
    height: 100vh;
    width: 100vw;
    background-color: rgba(0, 0, 0, 0.6);
    z-index: -1;
}

.title {
    z-index: 1;
    height: calc(100vh);
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 210px;
    color: rgb(234, 242, 255);
    overflow: hidden;
    --transform-scroll: 0;
    --transform-animation: 0;
    transform: translateY(var(--transform-scroll)) translateY(var(--transform-animation));
}

.container {
    display: flex;
    justify-content: center;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

.catalog {
    position: -webkit-sticky;
    position: sticky;
    top: 100px;
    left: 10px;
    width: calc(27.5% - 20px);
    filter: drop-shadow(0px 0px 10px rgba(0, 0, 0, 0.1));
    border-radius: 20px;
    padding: 30px 40px;
    display: flex;
    flex-direction: column;
    height: min-content;
    background: linear-gradient(135deg, #032d30 0%, #0a5c66 100%);
    margin-right: 20px;
}

.catalog div {
    font-size: 26px;
    color: white;
    cursor: pointer;
}

.back-wrapper {
    position: -webkit-sticky;
    position: sticky;
    top: calc(100vh);
    width: 60px;
    height: 60px;
    margin-top: auto;
    align-self: center;
}

.back-progress {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: conic-gradient(gray 0%, gray 100%);
}

.back {
    position: absolute;
    top: 10%;
    left: 10%;
    height: 80%;
    width: 80%;
    border-radius: 50%;
    background-color: white;
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
}

.back img {
    height: 40px;
}

.active {
    color: rgb(255, 255, 255) !important;
    font-weight: bold;
}

.box {
    background-color: rgba(255, 255, 255);
    border-radius: 10px;
    padding: 30px 60px;
    margin-bottom: 30px;
    width: 100%;
}

.main {
    filter: drop-shadow(0px 0px 10px rgba(0, 0, 0, 0.1));
    border-radius: 10px;
    padding: 0px 40px;
    font-size: 20px;
    color: black;
    font-weight: 400;
    display: flex;
    flex-direction: column;
    align-items: center;
    width: calc(70% - 10px);
    margin-left: 10px;
    margin-right: 2.5%;
    margin-bottom: 20px;
}

.paragraph {
    align-self: start;
    margin: 15px 0;
    text-align: justify;
    line-height: 1.6;
}

.pic {
    width: 80%;
    max-width: 800px;
    margin: 20px 0;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    align-self: center;
}

.fade-in {
    animation: fadeIn 1s ease-in-out forwards;
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.table {
    width: 100%;
    margin: 20px 0;
    border-collapse: collapse;
}

.t-title,
.t-columns {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 0;
}

.t-title {
    font-weight: bold;
    border-bottom: solid 2px rgb(70, 70, 70);
    margin-bottom: 10px;
}

.t-columns {
    padding: 8px 0;
    border-bottom: solid 1px rgb(207, 207, 207);
}

.t-columns:hover {
    background-color: #f5f5f5;
}

.col-1 {
    flex: 0.8;
    margin-left: 10px;
}

.col-2 {
    flex: 1;
}

.col-3 {
    flex: 1.7;
}

.col-4 {
    flex: 1;
}

.col-2 a {
    color: #0a5c66;
    text-decoration: none;
}

.col-2 a:hover {
    text-decoration: underline;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    align-self: center;
    margin-bottom: 20px;
    color: #032d30;
}

footer {
    background: linear-gradient(135deg, #032d30 0%, #0a5c66 100%);
    color: white;
    padding: 3rem 2rem;
    margin-top: 4rem;
    text-align: center;
}

/* Responsive styles */
@media (max-width: 1024px) {
    .container {
        flex-direction: column;
    }

    .catalog {
        position: relative;
        width: 100%;
        top: 0;
        margin-bottom: 20px;
        height: auto;
    }

    .main {
        width: 100%;
        margin-left: 0;
    }

    .box {
        padding: 20px;
    }

    .paragraph {
        font-size: 18px;
    }
}

@media (max-width: 768px) {

    .t-title,
    .t-columns {
        flex-direction: column;
        align-items: flex-start;
    }

    .col-1,
    .col-2,
    .col-3,
    .col-4 {
        flex: 1;
        margin: 5px 0;
        width: 100%;
    }

    .catalog {
        padding: 20px;
    }

    .catalog div {
        font-size: 20px;
    }

    .section-title {
        font-size: 28px;
    }
}

/* Preloader 样式 */
#preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: #e6f2ff;
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

.preloader-image {
    width: 200px;
    height: 200px;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0% {
        transform: scale(1);
        opacity: 1;
    }

    50% {
        transform: scale(1.1);
        opacity: 0.8;
    }

    100% {
        transform: scale(1);
        opacity: 1;
    }
}