/* =====================================================
   RESET
===================================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}


html {
    scroll-behavior: smooth;
}


body {

    font-family: "Inter", Arial, sans-serif;

    background: #fff;

    color: #111;

    font-weight: 300;

    line-height: 1.6;

    -webkit-font-smoothing: antialiased;

}


img {

    width: 100%;

    display: block;

}


a {

    color: inherit;

    text-decoration: none;

}




/* =====================================================
   VARIABLES
===================================================== */


:root {

    --content-width: min(1100px, 80vw);

    --side-padding: 50px;


    --grey: #777;

}





/* =====================================================
   GLOBAL GRID
===================================================== */


main {

    margin-left: 0;

    padding-top: 90px;

}

h2 {

    scroll-margin-top: 40px;

}



/* =====================================================
   NAVIGATION
===================================================== */

.site-navigation {

    position: fixed;

    top: 0;
    left: 0;

    width: 100%;

    padding: 25px 45px;

    display: flex;

    justify-content: space-between;

    align-items: baseline;

    z-index: 100;

    background: #fff;

}


.identity-name {

    display: block;

    font-size: 28px;

    line-height: .9;

    font-weight: 500;

    letter-spacing: -.07em;

}


.site-navigation nav {

    display: flex;

    align-items: baseline;

    gap: 25px;

}


.site-navigation nav a {

    font-size: 15px;

    line-height: 1;

    font-weight: 400;

    color: #111;

    transition: opacity .25s ease;

}


.site-navigation nav a:hover {

    opacity: .45;

}

/* =====================================================
   HERO
===================================================== */

.hero {

    min-height: 100vh;

    padding: 40px 50px;

    display: flex;

    align-items: center;

}


.hero-image {

    width: 100%;

    max-width: 1500px;

}


.hero-image img {

    width: 100%;

    display: block;

}




/* =====================================================
   CHAPTER STRUCTURE
===================================================== */

.intro-section,
.chapter-preview,
.contact {

    padding: 90px 50px;

    display: grid;

    grid-template-columns: 80px minmax(300px, var(--content-width));

    gap: 60px;

}



.chapter-number {

    font-size:12px;

    color:var(--grey);

    letter-spacing:.1em;

}



.chapter-content {

    max-width:1000px;

}




/* =====================================================
   TITLES
===================================================== */


.chapter-content h2 {

    font-size: clamp(28px, 3vw, 42px);

    font-weight: 500;

    letter-spacing: -.04em;

    line-height: 1;

    margin: 0 0 35px;

}




/* =====================================================
   TEXT
===================================================== */


.reading-text {

    width: 95%;
    max-width: none;

}


.reading-text p {

    font-size: 18px;

    line-height: 1.5;

    margin-bottom: 25px;

}


.chapter-content > p {

    width: 95%;
    max-width: none;

    font-size: 17px;

    line-height: 1.5;

    margin-top: 30px;

}




/* =====================================================
   IMAGES
===================================================== */


.chapter-content figure {

    width: 100%;

}


.chapter-content img {

    display: block;

}


/* =====================================================
   LINKS
===================================================== */


.more {

    display:inline-block;

    margin-top:35px;

    font-size:13px;

    text-transform:uppercase;

    letter-spacing:.12em;

    border-bottom:1px solid #111;

    padding-bottom:5px;

}


/* =====================================================
   TALKS LIST
===================================================== */


.talk-list {

    max-width:700px;

}



.talk-list article {

    display:grid;

    grid-template-columns:80px 1fr;

    gap:30px;

    padding:25px 0;

    border-bottom:1px solid #eee;

}



.talk-list .year {

    font-size:13px;

    color:#777;

}



.talk-list p {

    font-size:17px;

    line-height:1.5;

}



.talk-list em {

    font-style:normal;

}



/* =====================================================
   CONTACT
===================================================== */


.contact p {

    font-size:22px;

}






/* =====================================================
   FOOTER
===================================================== */


footer {


    padding:50px;

    font-size:12px;

    border-top:1px solid #eee;

}



/* =====================================================
   BACK TO TOP
===================================================== */

.back-to-top {
    display: none;
}


@media(max-width: 900px) {

    .back-to-top {

        display: block;

        position: fixed;

        right: 25px;

        bottom: 25px;

        width: 40px;

        height: 40px;

        border: 1px solid #111;

        border-radius: 50%;

        background: #fff;

        font-size: 18px;

        line-height: 37px;

        text-align: center;

        z-index: 100;

        opacity: 0;

        pointer-events: none;

        transition: opacity .3s ease;

    }


    .back-to-top.visible {

        opacity: 1;

        pointer-events: auto;

    }

}


/* =====================================================
   MOBILE
===================================================== */


@media(max-width: 900px) {

    .site-navigation {

        position: relative;

        width: 100%;

        height: auto;

        padding: 25px 30px;

        display: block;

    }


   


    .site-navigation nav {

        margin-top: 25px;

        flex-direction: row;

        flex-wrap: wrap;

        gap: 8px 18px;

    }


    .site-navigation nav a {

        font-size: 14px;

    }


    main {
        margin-left: 0;
        padding-top: 0px;
    }


    .hero {

        min-height: auto;

        padding: 30px;

    }


    .intro-section,
    .chapter-preview,
    .contact {

        display: block;

        padding: 35px 30px;

    }


    .chapter-number {

        margin-bottom: 25px;

    }


    .chapter-content h2 {

        font-size: 42px;

        margin-bottom: 35px;

    }



    footer {

        margin-left:0;

        padding:30px;

    }

}