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

html {
    scroll-behavior: smooth;
}

body {
    font-family: Georgia, "Times New Roman", serif;
    color: #fff;
    background-image: url("IMG_3937.JPG");
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
}

header {
    position: sticky;
    top: 0;
    z-index: 1;
    height: 4rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.1rem 2.5rem;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(4px);
}

footer {
    height: 3rem;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.45);
    backdrop-filter: blur(4px);
}

header a,
header span,
footer a {
    color: #fff;
    text-decoration: none;
    font-size: 1.05rem;
    letter-spacing: 0.04em;
}

header a:hover,
footer a:hover {
    text-decoration: underline;
}

main section {
    min-height: calc(100vh - 7rem);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 2rem;
    gap: 0.7rem;
    scroll-margin-top: 4rem;
}

main h1,
main h2,
main p,
main li,
main a {
    color: #c5e3a6;
    -webkit-text-stroke: 1.5px #000;
    paint-order: stroke fill;
    text-shadow:
        -1px -1px 0 #000,
        1px -1px 0 #000,
        -1px 1px 0 #000,
        1px 1px 0 #000;
}

main h1 {
    font-size: 3.4rem;
    letter-spacing: 0.04em;
}

main p {
    font-size: 1.35rem;
}

main h2 {
    margin-top: 1.4rem;
    font-size: 1.5rem;
}

main ul {
    list-style-position: inside;
    font-size: 1.15rem;
}

main h1.talk-title {
    max-width: 60rem;
    font-size: clamp(1.8rem, 4vw, 3rem);
}

main ul.talk-points {
    list-style-position: outside;
    text-align: left;
    font-size: clamp(1.15rem, 2.5vw, 1.6rem);
    line-height: 1.6;
    margin: 1.5rem 0;
    padding-left: 1.5rem;
}

.talk-photos {
    display: grid;
    grid-template-columns: 9fr 16fr 9fr;
    gap: 1rem;
    width: 100%;
    max-width: 60rem;
    margin: 1rem 0;
}

.talk-photos img {
    width: 100%;
    height: auto;
    border: 2px solid rgba(255, 255, 255, 0.8);
    border-radius: 0.5rem;
    box-shadow: 0 0.5rem 1.5rem rgba(0, 0, 0, 0.6);
    cursor: zoom-in;
}

.lightbox {
    position: fixed;
    inset: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0, 0, 0, 0.8);
    cursor: zoom-out;
}

.lightbox[hidden] {
    display: none;
}

.lightbox img {
    max-width: 90vw;
    max-height: 90vh;
    border: 2px solid rgba(255, 255, 255, 0.8);
    border-radius: 0.5rem;
}

main a {
    text-decoration: underline;
}

main a:hover {
    color: #ffd966;
}