/* --- Global box-sizing (prevents horizontal overflow from padding + width) --- */
*,
*::before,
*::after {
    box-sizing: border-box;
}

/* --- Skip link (visually hidden, still announced to screen readers) --- */
.skip-link {
    position: absolute;
    top: 0;
    left: 0;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0 0 0 0);
    clip-path: inset(50%);
    white-space: nowrap;
    border: 0;
}

/* --- Common (all pages) --- */

body {
    display: flex;
    flex-flow: column;
    min-height: 90vh;
    font-family: "BIZ UDGothic", sans-serif;
}

main {
    flex: 1;
}

header {
    text-align: center;
    padding: 2rem 1rem;
}

.tagline {
    color: #666;
    font-weight: normal;
    margin-top: 0.25rem;
}

footer {
    width: 100%;
    padding: 1rem;
    text-align: center;
    background-color: lightgray;
}

.social-icon {
    width: 1.75rem;
    height: 1.75rem;
    flex: 0 0 1.75rem;
}