/* ==================================================
   Basic
================================================== */

* {
    box-sizing: border-box;
}


html {
    scroll-behavior: smooth;
}


body {
    margin: 0;
    padding: 0;

    font-family:
        -apple-system,
        BlinkMacSystemFont,
        "Segoe UI",
        "Helvetica Neue",
        Arial,
        "Noto Sans JP",
        "Hiragino Kaku Gothic ProN",
        "Yu Gothic",
        sans-serif;

    color: #171717;
    background: #ffffff;

    line-height: 1.8;

    -webkit-font-smoothing: antialiased;
}


a {
    color: inherit;
}


img {
    max-width: 100%;
}



/* ==================================================
   Header
================================================== */

.header {
    position: fixed;

    top: 0;
    left: 0;

    width: 100%;
    min-height: 72px;

    padding: 0 5%;

    display: flex;
    align-items: center;
    justify-content: space-between;

    z-index: 1000;

    color: #ffffff;

    background:
        rgba(15, 15, 15, 0.48);

    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);

    border-bottom:
        1px solid rgba(255, 255, 255, 0.12);
}


.logo {
    color: #ffffff;

    text-decoration: none;

    font-size: 20px;
    font-weight: 600;

    letter-spacing: 1px;

    white-space: nowrap;
}


.nav {
    display: flex;

    align-items: center;

    gap: 28px;
}


.nav a {
    color: #ffffff;

    text-decoration: none;

    font-size: 12px;

    letter-spacing: 1.4px;

    transition:
        opacity 0.25s ease;
}


.nav a:hover {
    opacity: 0.55;
}



/* ==================================================
   Hero
================================================== */

.hero {
    position: relative;

    width: 100%;
    height: 100vh;
    min-height: 650px;

    background-image:
        url("image/hero.jpg");

    background-size: cover;

    background-position:
        center center;

    background-repeat:
        no-repeat;
}


.hero::after {
    content: "";

    position: absolute;

    inset: 0;

    background:
        linear-gradient(
            to bottom,
            rgba(0, 0, 0, 0.03) 0%,
            rgba(0, 0, 0, 0.03) 70%,
            rgba(0, 0, 0, 0.30) 100%
        );

    pointer-events: none;
}


.scroll-guide {
    position: absolute;

    left: 50%;
    bottom: 28px;

    transform:
        translateX(-50%);

    z-index: 2;

    color: #ffffff;

    text-align: center;
}


.scroll-text {
    display: block;

    font-size: 10px;

    letter-spacing: 4px;
}


.scroll-arrow {
    display: block;

    margin-top: 5px;

    font-size: 19px;

    animation:
        scrollArrow 1.8s
        ease-in-out
        infinite;
}


@keyframes scrollArrow {

    0%,
    100% {
        transform:
            translateY(0);
    }

    50% {
        transform:
            translateY(7px);
    }
}



/* ==================================================
   Screen-reader only
================================================== */

.sr-only {
    position: absolute;

    width: 1px;
    height: 1px;

    padding: 0;
    margin: -1px;

    overflow: hidden;

    clip:
        rect(0, 0, 0, 0);

    white-space: nowrap;

    border: 0;
}



/* ==================================================
   Common Sections
================================================== */

.section,
.intro {
    padding:
        120px 8%;
}


.section-inner {
    width: 100%;
    max-width: 1120px;

    margin:
        0 auto;
}


.section-label {
    margin:
        0 0 24px 0;

    color: #777777;

    font-size: 11px;

    font-weight: 600;

    letter-spacing: 4px;
}


.section h2,
.intro h2 {
    margin:
        0 0 38px 0;

    font-size:
        clamp(36px, 4vw, 54px);

    line-height: 1.2;

    font-weight: 500;

    letter-spacing: -1px;
}


.lead {
    max-width: 820px;

    margin:
        0 0 28px 0;

    font-size:
        clamp(18px, 2vw, 23px);

    line-height: 2;

    font-weight: 400;
}


.section p,
.intro p {
    max-width: 820px;
}



/* ==================================================
   Introduction
================================================== */

.intro {
    background: #ffffff;
}


.intro-title {
    font-family:
        Georgia,
        "Times New Roman",
        "Yu Mincho",
        "Hiragino Mincho ProN",
        serif;

    font-weight: 400 !important;
}



/* ==================================================
   Gray background
================================================== */

.section-gray {
    background: #f4f4f2;
}



/* ==================================================
   Profile
================================================== */

.profile-grid {
    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 1px;

    margin-top: 65px;

    background: #d8d8d8;
}


.profile-item {
    min-height: 330px;

    padding: 40px;

    background: #ffffff;
}


.item-number {
    margin:
        0 0 34px 0;

    color: #999999;

    font-size: 11px;

    letter-spacing: 2px;
}


.profile-item h3 {
    margin:
        0 0 25px 0;

    font-size: 23px;

    font-weight: 500;
}


.profile-item p {
    margin:
        5px 0;

    font-size: 15px;
}



/* ==================================================
   Career
================================================== */

.timeline {
    margin-top: 60px;

    border-bottom:
        1px solid #d5d5d5;
}


.timeline-item {
    display: grid;

    grid-template-columns:
        90px 1fr;

    gap: 25px;

    padding:
        38px 0;

    border-top:
        1px solid #d5d5d5;
}


.timeline-number {
    color: #999999;

    font-size: 12px;

    letter-spacing: 2px;
}


.timeline-content h3 {
    margin:
        0 0 12px 0;

    font-size:
        clamp(21px, 2vw, 27px);

    font-weight: 500;
}


.timeline-content p {
    margin: 0;

    color: #555555;
}



/* ==================================================
   Research
================================================== */

.research-grid {
    display: grid;

    grid-template-columns:
        repeat(2, 1fr);

    gap:
        55px 45px;

    margin-top: 70px;
}


.research-item {
    min-height: 260px;

    padding-top: 25px;

    border-top:
        1px solid #242424;
}


.research-item h3 {
    margin:
        20px 0 20px 0;

    font-size:
        clamp(22px, 2vw, 28px);

    font-weight: 500;

    line-height: 1.35;
}


.research-item p:last-child {
    color: #555555;
}



/* ==================================================
   Publications
================================================== */

.section-dark {
    color: #ffffff;

    background: #111111;
}


.section-label-light {
    color: #999999;
}


.dark-lead {
    color: #cccccc;
}


.achievement-grid {
    display: grid;

    grid-template-columns:
        repeat(3, 1fr);

    gap: 1px;

    margin-top: 75px;

    background:
        rgba(255, 255, 255, 0.20);
}


.achievement-item {
    min-height: 260px;

    padding: 45px;

    display: flex;

    flex-direction: column;

    justify-content:
        space-between;

    background: #111111;
}


.achievement-item strong {
    display: block;

    font-size:
        clamp(56px, 7vw, 90px);

    line-height: 1;

    font-weight: 300;
}


.achievement-item strong.achievement-text {
    font-size:
        clamp(48px, 6vw, 75px);
}


.achievement-item span {
    color: #aaaaaa;

    font-size: 14px;

    letter-spacing: 1px;
}


.publication-note {
    margin-top: 50px;

    color: #888888;

    font-size: 13px;
}



/* ==================================================
   Projects
================================================== */

.project-feature {
    display: grid;

    grid-template-columns:
        100px 1fr;

    gap: 40px;

    padding:
        48px 0 60px 0;

    border-top:
        1px solid #222222;
}


.project-feature:first-of-type {
    margin-top: 65px;
}


.project-number {
    color: #999999;

    font-size: 12px;

    letter-spacing: 2px;
}


.project-category {
    margin:
        0 0 10px 0;

    color: #888888;

    font-size: 11px;

    font-weight: 600;

    letter-spacing: 2.5px;
}


.project-content h3 {
    margin:
        0 0 24px 0;

    font-size:
        clamp(27px, 3vw, 38px);

    font-weight: 500;

    line-height: 1.3;
}


.project-lead {
    margin:
        0 0 22px 0;

    font-size: 20px;

    line-height: 1.8;
}


.project-content p:last-child {
    color: #555555;
}



/* ==================================================
   Message
================================================== */

.message {
    padding:
        140px 8%;

    color: #ffffff;

    background:
        #101010;
}


.message-inner {
    width: 100%;
    max-width: 1120px;

    margin:
        0 auto;
}


.message-small {
    margin: 0;

    font-size:
        clamp(19px, 2vw, 27px);
}


.message h2 {
    margin:
        4px 0 45px 0;

    font-family:
        Georgia,
        "Times New Roman",
        serif;

    font-size:
        clamp(48px, 7vw, 88px);

    line-height: 1.1;

    font-weight: 400;

    letter-spacing: -2px;
}


.message-japanese {
    margin: 0;

    color: #cccccc;

    font-size:
        clamp(16px, 1.7vw, 21px);

    line-height: 2;
}



/* ==================================================
   Contact
================================================== */

.contact {
    min-height: 650px;

    display: flex;

    align-items: center;

    text-align: center;
}


.contact .section-inner {
    display: flex;

    flex-direction: column;

    align-items: center;
}


.contact-lead {
    max-width: 680px;
}


.contact-button {
    display: inline-block;

    margin-top: 38px;

    padding:
        17px 30px;

    color: #111111;

    background: transparent;

    border:
        1px solid #111111;

    text-decoration: none;

    font-size:
        clamp(13px, 1.5vw, 16px);

    letter-spacing: 0.5px;

    transition:
        color 0.3s ease,
        background 0.3s ease,
        transform 0.3s ease;
}


.contact-button:hover {
    color: #ffffff;

    background: #111111;

    transform:
        translateY(-2px);
}



/* ==================================================
   Footer
================================================== */

.footer {
    min-height: 85px;

    padding:
        25px 5%;

    display: flex;

    justify-content:
        space-between;

    align-items: center;

    gap: 20px;

    color: #888888;

    background: #111111;

    font-size: 11px;

    letter-spacing: 1px;
}


.footer p {
    margin: 0;
}



/* ==================================================
   Tablet
================================================== */

@media (max-width: 1050px) {

    .nav {
        gap: 18px;
    }


    .nav a {
        font-size: 11px;
    }


    .profile-grid {
        grid-template-columns:
            repeat(2, 1fr);
    }


    .achievement-grid {
        grid-template-columns:
            repeat(3, 1fr);
    }

}



/* ==================================================
   Smartphone
================================================== */

@media (max-width: 768px) {

    .header {
        min-height: 60px;

        padding:
            0 5%;
    }


    .logo {
        font-size: 15px;
    }


    .nav {
        display: none;
    }


    .hero {
        height: 70vh;
        min-height: 500px;

        background-position:
            center center;
    }


    .section,
    .intro {
        padding:
            80px 7%;
    }


    .section h2,
    .intro h2 {
        font-size: 34px;
    }


    .lead {
        font-size: 18px;

        line-height: 1.9;
    }


    .profile-grid {
        grid-template-columns:
            1fr;
    }


    .profile-item {
        min-height: auto;

        padding: 35px;
    }


    .timeline-item {
        grid-template-columns:
            50px 1fr;

        gap: 15px;
    }


    .research-grid {
        grid-template-columns:
            1fr;

        gap: 40px;
    }


    .research-item {
        min-height: auto;
    }


    .achievement-grid {
        grid-template-columns:
            1fr;
    }


    .achievement-item {
        min-height: 200px;
    }


    .project-feature {
        grid-template-columns:
            1fr;

        gap: 10px;
    }


    .message {
        padding:
            90px 7%;
    }


    .message h2 {
        font-size: 47px;

        letter-spacing: -1px;
    }


    .contact {
        min-height: 550px;
    }


    .contact-button {
        width: 100%;

        word-break:
            break-all;
    }


    .footer {
        flex-direction:
            column;

        align-items:
            flex-start;

        gap: 3px;
    }

}



/* ==================================================
   Very small screens
================================================== */

@media (max-width: 420px) {

    .hero {
        height: 62vh;

        min-height: 440px;
    }


    .section,
    .intro {
        padding:
            65px 6%;
    }


    .section h2,
    .intro h2 {
        font-size: 30px;
    }


    .profile-item {
        padding: 28px;
    }


    .achievement-item {
        padding: 35px;
    }


    .message h2 {
        font-size: 40px;
    }

}