/* ===== Back Link ===== */
.back-link {
    position: fixed;
    top: 2rem;
    left: 2.5rem;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--dark-gray);
    text-decoration: none;
    transition: var(--transition);
    z-index: 100;
}

.back-link:hover {
    opacity: 0.5;
}

/* ===== Sidebar TOC ===== */
.essay-sidebar {
    position: fixed;
    top: 5rem;
    left: 2.5rem;
    width: 210px;
    z-index: 100;
}

.toc {
    display: flex;
    flex-direction: column;
    gap: 0;
}

/* Title: always bold, no bar */
.toc-title {
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 700;
    color: var(--dark-gray);
    padding-left: 0.75rem;
    padding-bottom: 0.6rem;
    margin-bottom: 0.2rem;
}

/* Section items: indented, light by default */
.toc-item {
    font-family: var(--font-sans);
    font-size: 0.8rem;
    font-weight: 400;
    color: var(--light-gray);
    text-decoration: none;
    padding: 0.25rem 0;
    padding-left: 1.5rem;
    border-left: 3px solid transparent;
    transition: color 0.2s ease, font-weight 0.2s ease, border-color 0.2s ease;
}

.toc-item:hover {
    color: var(--dark-gray);
}

/* Active section: bold, dark, left bar */
.toc-item.active {
    color: var(--dark-gray);
    font-weight: 600;
    border-left-color: var(--dark-gray);
}

/* ===== Article Content ===== */
.essay-article {
    max-width: 680px;
    margin: 0 auto;
    padding: 2rem 2rem 4rem;
}

.essay-header {
    text-align: center;
    margin-bottom: 3rem;
}

.essay-page-title {
    font-family: 'Libre Baskerville', serif;
    font-size: 2.2rem;
    font-weight: 400;
    color: var(--dark-gray);
    margin-bottom: 0.5rem;
    line-height: 1.3;
}

.essay-page-subtitle {
    font-family: var(--font-sans);
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--light-gray);
    font-style: italic;
    margin: 0 auto 0.9rem;
    max-width: 620px;
}

.essay-page-date {
    font-family: var(--font-sans);
    font-size: 0.8rem;
    color: var(--light-gray);
    font-style: italic;
}

/* ===== Essay Body ===== */
.essay-body p {
    font-family: 'Libre Baskerville', serif;
    font-size: 1.05rem;
    line-height: 1.8;
    color: var(--dark-gray);
    margin-bottom: 1.5rem;
    text-align: justify;
}

.essay-body h2 {
    font-family: 'Libre Baskerville', serif;
    font-size: 1.6rem;
    font-weight: 400;
    color: var(--dark-gray);
    margin-top: 3rem;
    margin-bottom: 1.5rem;
    line-height: 1.3;
}

.essay-body .math-block {
    text-align: center;
    margin: 2rem 0;
    font-size: 1.1rem;
}

/* ===== Code Blocks ===== */
.essay-body pre {
    background-color: #f6f6f6;
    border-radius: 6px;
    padding: 1.5rem;
    margin: 1.5rem 0;
    overflow-x: auto;
}

.essay-body code {
    font-family: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--dark-gray);
}

.essay-body p code {
    background-color: #f6f6f6;
    padding: 0.15rem 0.4rem;
    border-radius: 3px;
    font-size: 0.9rem;
}

/* ===== Essay Footer ===== */
.essay-footer {
    padding: 2rem 3rem;
}

/* Page-specific spacing tweaks for "What Companies Won't Automate" */
body.essay-ai-value .essay-article {
    padding-top: 2rem;
}

body.essay-ai-value .essay-header {
    margin-top: 24vh;
    margin-bottom: 2.5rem;
}

body.essay-ai-value .essay-body h2 {
    margin-top: 4.25rem;
}

/* ===== Responsive ===== */
@media (max-width: 1100px) {
    .essay-sidebar {
        display: none;
    }

    .back-link {
        position: relative;
        top: auto;
        left: auto;
        display: block;
        padding: 1.5rem 2rem 0;
    }
}

@media (max-width: 768px) {
    .back-link {
        padding: 1.25rem 1.5rem 0;
        font-size: 0.8rem;
    }

    .essay-article {
        padding: 1.5rem 1.5rem 3rem;
    }

    body.essay-ai-value .essay-article {
        padding-top: 1.5rem;
    }

    body.essay-ai-value .essay-header {
        margin-top: 16vh;
        margin-bottom: 2rem;
    }

    body.essay-ai-value .essay-body h2 {
        margin-top: 3rem;
    }

    .essay-header {
        margin-bottom: 2rem;
    }

    .essay-page-title {
        font-size: 1.8rem;
    }

    .essay-page-subtitle {
        font-size: 0.88rem;
        max-width: 100%;
    }

    .essay-body p {
        font-size: 0.95rem;
        line-height: 1.7;
        text-align: left;
    }

    .essay-body h2 {
        font-size: 1.3rem;
        margin-top: 2rem;
        margin-bottom: 1rem;
    }

    .essay-body pre {
        padding: 1rem;
        margin: 1rem 0;
    }

    .essay-body code {
        font-size: 0.75rem;
    }

    .essay-body .math-block {
        font-size: 0.95rem;
        margin: 1.5rem 0;
        overflow-x: auto;
    }

    .essay-footer {
        padding: 1rem 1.5rem;
    }
}

@media (max-width: 480px) {
    .back-link {
        padding: 1rem 1.25rem 0;
    }

    .essay-article {
        padding: 1.25rem 1.25rem 2rem;
    }

    body.essay-ai-value .essay-article {
        padding-top: 1.25rem;
    }

    body.essay-ai-value .essay-header {
        margin-top: 13vh;
        margin-bottom: 1.75rem;
    }

    .essay-page-title {
        font-size: 1.5rem;
    }

    .essay-page-subtitle {
        font-size: 0.84rem;
    }

    .essay-body p {
        font-size: 0.88rem;
    }

    .essay-body h2 {
        font-size: 1.15rem;
    }

    .essay-footer {
        padding: 1rem 1.25rem;
    }
}