@charset "UTF-8";
/* common */
:root {
    --primary-white: #F4F4F4;
    --primary-black: #0C0C0C;
    --contentPadding: 3%;
    --mainFont: "Sawarabi Mincho", serif;
}

html {
    font-size: 62.5%;
}

body {
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    font-family: var(--mainFont);
    font-weight: 400;
    font-style: normal;
    font-size: 1.8rem;
    line-height: 1.5;
    letter-spacing: 1.5px;
    background-color: var(--primary-black);
    color: var(--primary-white);
    padding: 70px;
}

img {
    width: 100%;
    display: block;
}

.title {
    font-size: 80px;
    font-weight: 500;
    letter-spacing: 3px;
}

.teacherBlock {
    display: flex;
    gap: 15px;
    font-size: 40px;
}

.container {
    margin-top: 70px;
    width: 100%;
    display: flex;
    gap: 150px;
}

.themeBlock {
    width: 60%;
}

.mainTheme {
    font-size: 50px;
    font-weight: 500;
    letter-spacing: 2.5px;
}

.photoBlock {
    position: relative;
    width: 100%;
    aspect-ratio: 16 / 9;
    overflow: hidden;
}

.photoBlock img {
    position: absolute;
    width: 100%;
    aspect-ratio: 16 / 9;
    object-fit: cover;
    top: 0;
    left: 0;
    opacity: 0;
    animation: fade 16s infinite;
}

.photoBlock img:nth-of-type(1) {
    animation-delay: 0s;
}
.photoBlock img:nth-of-type(2) {
    animation-delay: 4s;
}
.photoBlock img:nth-of-type(3) {
    animation-delay: 8s;
}
.photoBlock img:nth-of-type(4) {
    animation-delay: 12s;
}

@keyframes fade {
    0%   { opacity: 0; }
    10%   { opacity: 1; }
    25%  { opacity: 1; }
    35%  { opacity: 0; }
    100% { opacity: 0; }
}

.theme__txtBlock {
    margin-top: 30px;
}

.theme__topic {
    font-size: 50px;
    font-weight: 500;
}

.theme__txt {
    margin-top: 5px;
    font-size: 40px;
    letter-spacing: 2.5px;
}

.studentsBlock {
    display: flex;
    flex-direction: column;
    gap: 60px;
}

h2 {
    font-size: 40px;
    font-weight: 600;
    letter-spacing: 3px;
}

.memberList {
    margin-top: 30px;
    display: flex;
    flex-wrap: wrap;
    gap: 50px;
}

.member {
    padding-bottom: 30px;
    width: 35%;
}

.member a ,
.member p {
    display: block;
    font-size: 50px;
    border: 3px solid var(--primary-white);
    padding: 15px 40px;
    line-height: 1;
}

.member p {
    color: gray;
    border: 3px solid gray;
}

.member a {
    transition: .8s ease;
}

.member a:hover {
    color: var(--primary-black);
    border: 3px solid gray;
    background-color: gray;
    transition: .5s ease;
}

/* movie */
.body__movie {
    width: 100%;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 100px;
}

.movie__container {
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.movie__mainBlock {
    width: 100%;
}

.movie__topicBlock {
    display: flex;
    align-items: flex-end;
    gap: 30px;
}

.student {
    font-size: 50px;
    font-weight: 500;
    letter-spacing: 2px;
}

.group {
    font-size: 30px;
    font-weight: 500;
    letter-spacing: 2.5px;
    padding-bottom: 7px;
}

video {
    width: 100%;
    max-height: 90vh;
    aspect-ratio: 16 / 9;
    object-fit: contain;
    margin-top: 30px;
}

.btn {
    display: block;
    font-size: 40px;
    font-weight: 500;
    letter-spacing: 3px;
    border: 3px solid gray;
    color: var(--primary-black);
    background-color: gray;
    line-height: 1;
    padding: 15px 35px;
    transition: .8s ease;
}

.btn--back {
    margin-top: 40px;
}

.btn:hover {
    color: var(--primary-white);
    border: 3px solid var(--primary-white);
    background-color: var(--primary-black);
    transition: .5s ease;
}

.btn-nxt ,
.btn-pre {
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    font-size: 30px;
    width: 270px;
    padding: 10px 25px;
}