:root {
    --bg-light: #f4f4f6;
    --card-white: #ffffff;
    --text-main: #121212;
    --text-muted: #525252;
    --accent-blue: #0f62fe;
    --border-line: #e0e0e0;
}

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

body.light-body {
    font-family: 'IBM Plex Sans', -apple-system, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

/* Header */
.site-header {
    position: fixed;
    top: 0; left: 0; width: 100%;
    height: 70px;
    background: rgba(244, 244, 246, 0.9);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border-line);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 4rem;
    z-index: 1000;
}

.header-inner { display: flex; align-items: baseline; gap: 1rem; }
.brand-name { font-size: 1rem; font-weight: 600; letter-spacing: -0.2px; }
.brand-desc { font-size: 0.8rem; color: var(--text-muted); }

.header-nav { display: flex; gap: 1.5rem; }
.header-nav a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 500;
    transition: color 0.2s;
}
.header-nav a:hover { color: var(--text-main); }

/* Document Layout Container */
.document-container {
    max-width: 1357px;
    margin: 110px auto 4rem auto;
    padding: 0 4rem;
    display: flex;
    flex-direction: column;
    gap: 4rem;
}

/* Sections styled as clean white editorial cards */
.doc-section {
    background: var(--card-white);
    border: 1px solid var(--border-line);
    padding: 4.5rem;
    border-radius: 4px;
}

.section-counter {
    font-size: 0.7rem;
    font-weight: 600;
    letter-spacing: 1.5px;
    color: var(--accent-blue);
    display: block;
    margin-bottom: 1.5rem;
}

.doc-section h1 {
    font-family: 'IBM Plex Serif', serif;
    font-size: 2.75rem;
    font-weight: 300;
    letter-spacing: -0.02em;
    line-height: 1.15;
    margin-bottom: 2.5rem;
    color: #000;
}

.narrative-block {
    margin-bottom: 2rem;
}

.narrative-block h3 {
    font-size: 1rem;
    font-weight: 600;
    color: #000;
    margin-bottom: 0.4rem;
}

.narrative-block p, .body-copy {
    font-size: 1.05rem;
    color: var(--text-muted);
}

/* Editorial Pull Quotes */
.editorial-quote {
    font-family: 'IBM Plex Serif', serif;
    font-size: 1.2rem;
    font-weight: 300;
    font-style: italic;
    color: #1a1a1a;
    border-left: 2px solid var(--accent-blue);
    padding-left: 2rem;
    margin: 2.5rem 0;
    line-height: 1.6;
}

.quote-author {
    font-family: 'IBM Plex Sans', sans-serif;
    font-size: 0.85rem;
    font-style: normal;
    font-weight: 500;
    color: var(--text-muted);
    display: block;
    margin-top: 0.5rem;
}

/* Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin: 2.5rem 0;
}

.metric-card {
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 2px;
}

.metric-val {
    font-size: 2.2rem;
    font-weight: 600;
    color: var(--accent-blue);
    display: block;
    margin-bottom: 0.5rem;
}

.metric-txt {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.5;
}

/* Callouts & Schema Code Blocks */
.callout-box {
    background: var(--bg-light);
    padding: 1.5rem 2rem;
    border-left: 2px solid #000;
    margin: 2rem 0;
}

.schema-code-block {
    background: #111;
    color: #fff;
    padding: 2.5rem;
    border-radius: 2px;
    margin: 2.5rem 0;
}

.code-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--accent-blue);
    display: block;
    margin-bottom: 0.75rem;
}

.schema-code-block p { color: #a3a3a3; font-size: 0.95rem; }
.schema-code-block code {
    display: block;
    background: #000;
    padding: 1rem;
    font-family: monospace;
    color: #38bdf8;
    margin: 1rem 0;
    font-size: 0.9rem;
    border-radius: 2px;
}
.code-sub { font-size: 0.85rem !important; color: #737373 !important; }

/* Action Steps */
.action-steps {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    margin: 2.5rem 0;
}

.action-step-item {
    display: flex;
    gap: 1.5rem;
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 2px;
    align-items: flex-start;
}

.step-num {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--accent-blue);
}

.action-step-item h4 { font-size: 1rem; margin-bottom: 0.3rem; color: #000; }
.action-step-item p { font-size: 0.9rem; color: var(--text-muted); }

/* Closing Thought */
.closing-thought-box {
    text-align: center;
    background: var(--bg-light);
    padding: 3rem 2rem;
    margin-top: 3rem;
    border-radius: 2px;
}

.closing-label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 2px; color: var(--accent-blue); font-weight: 600; display: block; margin-bottom: 1rem; }
.closing-thought-box p { font-family: 'IBM Plex Serif', serif; font-size: 1.25rem; font-style: italic; color: #000; max-width: 600px; margin: 0 auto 2rem auto; line-height: 1.5; }

.clean-cta-btn {
    display: inline-block;
    background: var(--text-main);
    color: #fff;
    padding: 0.8rem 2rem;
    border-radius: 2px;
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: background 0.2s;
}
.clean-cta-btn:hover { background: var(--accent-blue); }

/* Source Footnotes */
.source-foot {
    margin-top: 3rem;
    padding-top: 1rem;
    border-top: 1px solid var(--border-line);
    font-size: 0.75rem;
    color: var(--text-muted);
}
.source-foot a { color: var(--accent-blue); text-decoration: none; }
.source-foot a:hover { text-decoration: underline; }

/* Footer */
.site-footer {
    text-align: center;
    padding: 3rem;
    font-size: 0.8rem;
    color: var(--text-muted);
    background: #e5e5e7;
    border-top: 1px solid var(--border-line);
}

/* Mobile Adjustments */
@media (max-width: 768px) {
    .site-header { padding: 0 1.5rem; }
    .header-nav { display: none; }
    .doc-section { padding: 2.5rem 1.5rem; }
    .metrics-grid { grid-template-columns: 1fr; }
    .doc-section h1 { font-size: 2rem; }
}
/* =========================================
   Mobile Responsiveness (Screens under 768px)
   ========================================= */
@media (max-width: 768px) {
    
    /* 1. Header Adjustments */
    .site-header { 
        padding: 0 1.5rem; 
    }
    .header-nav { 
        display: none; /* Hides the top nav links so they don't clutter small screens */
    }

    /* 2. Main Container & Spacing */
    .document-container {
        margin: 90px auto 2rem auto; /* Reduces the top margin */
        padding: 0 1rem; /* Pulls the edges slightly closer to the screen border */
        gap: 2rem; /* Reduces the huge gaps between sections */
    }

    /* 3. Section Cards */
    .doc-section { 
        padding: 2.5rem 1.5rem; /* Drastically reduces the thick internal padding for small screens */
    }

    /* 4. Typography Scaling */
    .doc-section h1 { 
        font-size: 2rem; /* Shrinks the massive headlines so they fit neatly */
        margin-bottom: 1.5rem;
    }
    
    .editorial-quote {
        font-size: 1.1rem;
        padding-left: 1.5rem;
        margin: 2rem 0;
    }

    /* 5. Force Single Columns for Grids & Flex Layouts */
    .metrics-grid { 
        grid-template-columns: 1fr; /* Forces the two stats boxes to stack on top of each other */
        gap: 1.5rem;
    }

    .action-step-item {
        flex-direction: column; /* Stacks the step number above the text */
        gap: 1rem;
        padding: 1.5rem;
    }
}