/*
 * Search Growth Lab public layout.
 *
 * The Lab is intentionally a lightweight reading experience rather than a
 * learning-management system. Desktop readers keep the published lesson path
 * visible at the left; narrow screens replace it with a native disclosure list.
 */

.lab-hero {
    padding: 72px 0 56px;
    border-bottom: 1px solid var(--line);
    background: #fff;
}

.lab-hero h1 {
    max-width: 860px;
    margin: 8px 0 12px;
    font-size: clamp(38px, 5vw, 62px);
    line-height: 1.02;
    letter-spacing: -.05em;
}

.lab-hero p {
    max-width: 720px;
    margin: 0;
    color: var(--muted);
    font-size: 17px;
    line-height: 1.65;
}

.lab-shell {
    display: grid;
    grid-template-columns: 250px minmax(0, 1fr);
    gap: 56px;
    padding-top: 56px;
    padding-bottom: 96px;
}

.lab-lesson-shell {
    align-items: start;
}

.lab-sidebar {
    position: sticky;
    top: 24px;
    align-self: start;
    padding-right: 24px;
    border-right: 1px solid var(--line);
}

.site-header.is-sticky ~ main .lab-sidebar {
    top: calc(var(--site-header-height, 64px) + 24px);
}

.lab-sidebar-title {
    display: block;
    margin-bottom: 24px;
    color: var(--text);
    font-size: 15px;
    font-weight: 800;
}

.lab-sidebar section + section {
    margin-top: 28px;
}

.lab-sidebar h2 {
    margin: 0 0 9px;
    color: #64748b;
    font-size: 11px;
    letter-spacing: .08em;
    text-transform: uppercase;
}

.lab-sidebar section a {
    display: grid;
    grid-template-columns: 26px minmax(0, 1fr);
    gap: 8px;
    margin: 2px -10px;
    padding: 8px 10px;
    border-radius: 8px;
    color: #475569;
    font-size: 13px;
    line-height: 1.4;
}

.lab-sidebar section a span {
    color: #94a3b8;
    font-variant-numeric: tabular-nums;
}

.lab-sidebar section a:hover,
.lab-sidebar section a.active {
    background: var(--soft);
    color: var(--blue);
}

.lab-sidebar section a.active {
    font-weight: 750;
}

.lab-mobile-nav {
    display: none;
}

.lab-index-main {
    max-width: 880px;
}

.lab-intro {
    max-width: 800px;
    margin-top: 0;
}

.lab-start-card,
.lab-practice-card {
    margin-top: 34px;
    padding: 28px;
    border: 1px solid var(--line);
    border-radius: 14px;
    background: #fff;
    box-shadow: 0 10px 32px #0f17210a;
}

.lab-start-card > span,
.lab-practice-card > span,
.lab-lesson-head > span {
    color: var(--blue);
    font-size: 10px;
    font-weight: 800;
    letter-spacing: .12em;
    text-transform: uppercase;
}

.lab-start-card h2,
.lab-practice-card h2 {
    margin: 8px 0 10px;
    font-size: 28px;
    letter-spacing: -.035em;
}

.lab-start-card p,
.lab-practice-card p {
    max-width: 700px;
    color: var(--muted);
    line-height: 1.7;
}

.lab-start-card .button {
    margin-top: 8px;
}

.lab-practice-links {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 18px;
}

.lab-practice-links a,
.lab-practice-links span {
    padding: 7px 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    color: #475569;
    font-size: 12px;
}

.lab-lesson {
    width: min(100%, 820px);
}

.lab-lesson-head {
    padding-bottom: 30px;
    border-bottom: 1px solid var(--line);
}

.lab-lesson-head h1 {
    margin: 10px 0 12px;
    font-size: clamp(38px, 5vw, 58px);
    line-height: 1.04;
    letter-spacing: -.05em;
}

.lab-lesson-head p {
    max-width: 720px;
    margin: 0;
    color: var(--muted);
    font-size: 17px;
    line-height: 1.65;
}

.lab-content {
    max-width: 780px;
    margin-top: 36px;
}

.lab-content h2 {
    margin-top: 42px;
}

.lab-content h2:first-child {
    margin-top: 0;
}

.lab-prev-next {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 18px;
    margin-top: 56px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
}

.lab-prev-next a:last-child {
    text-align: right;
}

.lab-prev-next a {
    color: var(--blue);
    font-weight: 700;
    line-height: 1.5;
}

@media (max-width: 860px) {
    .lab-shell {
        display: block;
        padding-top: 32px;
    }

    .lab-sidebar {
        display: none;
    }

    .lab-mobile-nav {
        display: block;
        margin-bottom: 30px;
        padding: 12px 14px;
        border: 1px solid var(--line);
        border-radius: 10px;
        background: #fff;
    }

    .lab-mobile-nav summary {
        cursor: pointer;
        font-weight: 750;
    }

    .lab-mobile-nav strong,
    .lab-mobile-nav a {
        display: block;
    }

    .lab-mobile-nav strong {
        margin-top: 16px;
        color: #64748b;
        font-size: 11px;
        text-transform: uppercase;
    }

    .lab-mobile-nav a {
        padding: 7px 0;
        color: #475569;
    }

    .lab-mobile-nav a[aria-current="page"] {
        color: var(--blue);
        font-weight: 750;
    }
}

@media (max-width: 560px) {
    .lab-hero {
        padding: 48px 0 38px;
    }

    .lab-prev-next {
        grid-template-columns: 1fr;
    }

    .lab-prev-next a:last-child {
        text-align: left;
    }
}