/* --- 1. Variables & Reset --- */
:root {
    --bg-main: #10131A;
    --bg-surface: #1E293B;
    --accent: #4482E9;
    --text-main: #FFFFFF;
    --text-muted: #94A3B8;
    --border: rgba(255, 255, 255, 0.1);
}

* { box-sizing: border-box; }

body {
    margin: 0; padding: 0;
    background-color: var(--bg-main);
    color: var(--text-main);
    font-family: 'Inter', system-ui, sans-serif;
    line-height: 1.6;
}

.container {
    max-width: 850px;
    margin: 60px auto;
    padding: 0 20px;
}

/* --- 2. Headers & Typography --- */
h1 { font-size: 3.5rem; color: var(--accent); margin-bottom: 10px; letter-spacing: -2px; }
h2 { color: var(--text-main); font-size: 2rem; margin-top: 50px; border-left: 4px solid var(--accent); padding-left: 15px; }
h3 { color: var(--accent); margin-top: 30px; font-size: 1.3rem; }
h4 { margin-bottom: 5px; color: #fff; }
p { color: var(--text-muted); margin-bottom: 20px; }
hr { border: 0; border-top: 1px solid var(--bg-surface); margin: 60px 0; }

.meta-info { font-size: 1.1rem; margin-bottom: 30px; }

/* --- 3. Buttons & Links --- */
.download-zone { display: flex; gap: 15px; margin-bottom: 40px; }

.btn-primary, .btn-secondary {
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: 0.3s;
}

.btn-primary { background: var(--accent); color: white; }
.btn-primary:hover { background: #3569c7; transform: translateY(-2px); }

.btn-secondary { border: 1px solid var(--accent); color: var(--accent); }
.btn-secondary:hover { background: rgba(68, 130, 233, 0.1); }

.link-text { color: var(--accent); text-decoration: none; font-weight: 600; }

/* --- 4. ERD & Images --- */
.image-container {
    background: var(--bg-surface);
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    margin: 20px 0;
}

.responsive-img {
    max-width: 100%;
    height: auto;
    border-radius: 4px;
}

.caption { font-size: 0.85rem; margin-top: 10px; font-style: italic; }

/* --- 5. Tables & Quotes --- */
table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    background: var(--bg-surface);
    border-radius: 8px;
    overflow: hidden;
}

th, td { padding: 15px; text-align: left; border-bottom: 1px solid var(--bg-main); }
th { background: rgba(68, 130, 233, 0.2); color: #C5D2E8; }

blockquote {
    border-left: 4px solid var(--accent);
    background: var(--bg-surface);
    padding: 20px;
    margin: 20px 0;
    font-style: italic;
    color: var(--text-main);
}

/* --- 6. Reflection Boxes --- */
.reflection-box {
    background: var(--bg-surface);
    padding: 25px;
    border-radius: 12px;
    margin-bottom: 20px;
}

/* --- 7. Data Collection Sub-Categories --- */
.data-collection-content h4 {
    margin-top: 25px;
    margin-bottom: 10px;
    text-transform: none;
    letter-spacing: normal;
    color: var(--accent);
    opacity: 0.9;
    font-weight: 600
}

.data-collection-content h4::after { display: none; }

.test-group {
    margin: 10px 0 25px 0;
    padding-left: 15px;
    border-left: 1px solid var(--border);
}

.test-question {
    color: #f0f0f0;
    font-weight: 400;
    font-size: 1rem;
    margin-bottom: 6px;
    display: block;
}

.variable-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.variable-list li {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.6;
}

.variable-list li strong {
    color: var(--accent);
    font-size: 0.7rem;
    font-family: monospace;
    margin-right: 8px;
    display: inline-block;
    width: 25px;
    opacity: 0.8;
}

/* Specific styling for the Future Improvements list to override the global list-style: none */
.future-list {
    list-style: none;
    padding: 0
}

.future-list li {
    margin-bottom: 12px;
    border-left: 1px solid var(--border);
    padding-left: 15px;
 }

.future-list p, li p {
    margin: 0;
}