.resources-hero {
    padding: 8rem 2.5rem 3rem;
    width: 100%;
    max-width: 100%;
    margin: 0 auto;
    text-align: center;
    box-sizing: border-box;
}

        .back-link {
            display: inline-flex;
            align-items: center;
            gap: 0.5rem;
            color: var(--primary);
            font-weight: 600;
            font-size: 0.95rem;
            margin-bottom: 1.5rem;
            transition: transform var(--transition-fast);
        }

        .back-link:hover {
            transform: translateX(-4px);
            color: var(--secondary);
        }

        .resources-hero h1 {
            font-size: 3rem;
            margin-bottom: 0.5rem;
            background: linear-gradient(135deg, var(--text-primary) 40%, #1e3a8a 100%);
            -webkit-background-clip: text;
            background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .chapter-ref {
            display: inline-block;
            font-size: 0.95rem;
            font-weight: 700;
            color: var(--secondary);
            margin-bottom: 1rem;
            text-transform: uppercase;
            letter-spacing: 0.05em;
        }

        .resources-hero p {
            font-size: 1.15rem;
            color: var(--text-secondary);
            max-width: 700px;
            margin: 0 auto 3rem;
        }

        .tool-container {
    width: 100%;
    max-width: 100%;
    margin: 0 auto 4rem;
    padding: 0 2.5rem;
    display: grid;
    grid-template-columns: 1.3fr 0.7fr;
    gap: 2.5rem;
    align-items: start;
    box-sizing: border-box;
}

        @media (max-width: 1024px) {
            .tool-container {
                grid-template-columns: 1fr;
            }
        }

        .card-panel {
            background: var(--bg-card);
            backdrop-filter: blur(8px);
            -webkit-backdrop-filter: blur(8px);
            border: 1px solid var(--border-color);
            border-radius: 16px;
            padding: 2.5rem;
            box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.02);
            margin-bottom: 2rem;
        }

        .card-panel h2 {
            font-size: 1.5rem;
            margin-bottom: 1rem;
            color: var(--text-primary);
        }

        /* Tabs Menu */
        .tabs-menu {
            display: flex;
            gap: 0.5rem;
            margin-bottom: 2rem;
            border-bottom: 2px solid var(--border-color);
            padding-bottom: 0.5rem;
            flex-wrap: wrap;
        }

        .tab-btn {
            border: none;
            background: transparent;
            padding: 0.6rem 1.2rem;
            font-family: var(--font-heading);
            font-size: 0.9rem;
            font-weight: 700;
            color: var(--text-secondary);
            cursor: pointer;
            border-radius: 6px;
            transition: all var(--transition-fast);
        }

        .tab-btn:hover {
            background: #f1f5f9;
            color: var(--text-primary);
        }

        .tab-btn.active {
            background: var(--primary-glow);
            color: var(--primary);
        }

        .tab-pane {
            display: none;
        }

        .tab-pane.active {
            display: block;
        }

        /* Forms Layout */
        .calc-grid {
            display: grid;
            grid-template-columns: 1fr 1fr;
            gap: 1.5rem;
            margin-bottom: 1.5rem;
        }

        @media (max-width: 600px) {
            .calc-grid {
                grid-template-columns: 1fr;
            }
        }

        .calc-group {
            background: #f8fafc;
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 1.25rem;
        }

        .calc-group h3 {
            font-size: 1rem;
            margin-bottom: 1rem;
            color: var(--text-primary);
            font-family: var(--font-heading);
            border-bottom: 1px solid var(--border-color);
            padding-bottom: 0.5rem;
        }

        .input-wrapper {
            margin-bottom: 0.75rem;
        }

        .input-wrapper label {
            display: block;
            font-size: 0.8rem;
            font-weight: 600;
            color: var(--text-secondary);
            margin-bottom: 0.25rem;
        }

        .input-wrapper input, .input-wrapper textarea {
            width: 100%;
            padding: 0.5rem;
            border-radius: 6px;
            border: 1px solid var(--border-color);
            font-size: 0.95rem;
            color: var(--text-primary);
            outline: none;
            font-family: inherit;
            transition: border var(--transition-fast);
        }

        .input-wrapper input:focus, .input-wrapper textarea:focus {
            border-color: var(--primary);
        }

        .input-wrapper textarea {
            height: 120px;
            font-family: monospace;
            font-size: 0.85rem;
            resize: vertical;
        }

        /* Output styling */
        .verdict-box {
            border-radius: 8px;
            padding: 1.5rem;
            text-align: center;
            margin-bottom: 1.5rem;
            font-weight: 700;
            font-size: 1.1rem;
            transition: all var(--transition-normal);
        }

        .verdict-sig { background: #d1fae5; color: #065f46; border: 1px solid rgba(6, 95, 70, 0.2); }
        .verdict-nonsig { background: #fee2e2; color: #991b1b; border: 1px solid rgba(153, 27, 27, 0.2); }
        .verdict-empty { background: #f1f5f9; color: var(--text-secondary); border: 1px solid var(--border-color); }

        .ab-settings-grid {
            display: grid;
            grid-template-columns: repeat(2, minmax(0, 1fr));
            gap: 1rem;
            margin-bottom: 0.75rem;
        }

        .metrics-summary-grid {
            display: grid;
            grid-template-columns: repeat(3, 1fr);
            gap: 1rem;
            margin-bottom: 1.5rem;
        }

        .metrics-summary-grid-four {
            grid-template-columns: repeat(4, minmax(0, 1fr));
        }

        .metric-summary-card {
            background: white;
            border: 1px solid var(--border-color);
            border-radius: 8px;
            padding: 1rem;
            text-align: center;
        }

        .metric-lbl {
            font-size: 0.75rem;
            color: var(--text-muted);
            font-weight: 600;
            text-transform: uppercase;
        }

        .metric-val {
            font-size: 1.25rem;
            font-weight: 800;
            color: var(--text-primary);
            margin-top: 0.25rem;
        }

        .assumptions-panel {
            background: #f8fafc;
            border: 1px solid var(--border-color);
            border-left: 4px solid var(--primary);
            border-radius: 8px;
            padding: 1rem 1.25rem;
            margin-bottom: 1.5rem;
        }

        .assumptions-panel h3 {
            color: var(--text-primary);
            font-size: 1rem;
            margin: 0 0 0.5rem;
        }

        .assumptions-panel ul {
            color: var(--text-secondary);
            font-size: 0.85rem;
            line-height: 1.5;
            margin: 0;
            padding-left: 1.25rem;
        }

        .assumptions-panel li + li {
            margin-top: 0.25rem;
        }

        /* Stats definitions block */
        .concept-card {
            border: 1px solid var(--border-color);
            border-radius: 10px;
            padding: 1.25rem;
            background: white;
            margin-bottom: 1.25rem;
        }

        .concept-card h3 {
            font-size: 1.05rem;
            font-weight: 700;
            margin-bottom: 0.5rem;
            color: var(--text-primary);
            display: flex;
            align-items: center;
            gap: 0.5rem;
        }

        .concept-card p {
            font-size: 0.85rem;
            color: var(--text-secondary);
            line-height: 1.5;
        }

        code.math-formula {
            display: block;
            background: #f1f5f9;
            padding: 0.75rem;
            border-radius: 6px;
            font-family: monospace;
            font-size: 0.85rem;
            color: #1e293b;
            margin: 0.75rem 0;
            overflow-x: auto;
        }

        /* Bibliography block */
        .bibliography-section {
    width: 100%;
    max-width: 100%;
    margin: 0 auto 6rem;
    padding: 2rem 2.5rem 0;
    border-top: 1px solid var(--border-color);
    box-sizing: border-box;
}

        .bibliography-section h3 {
            font-family: var(--font-heading);
            font-size: 1.1rem;
            color: var(--text-primary);
            margin-bottom: 1rem;
        }

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

        .bibliography-list li {
            font-size: 0.85rem;
            color: var(--text-secondary);
            margin-bottom: 0.75rem;
            line-height: 1.5;
            text-indent: -1.5rem;
            padding-left: 1.5rem;
        }

        .bibliography-list a {
            color: var(--primary);
            text-decoration: underline;
        }

.intro-text { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 1.5rem; line-height: 1.6; }

.card-panel-no-margin { margin-bottom: 0; }
.stat-section-desc { color: var(--text-secondary); font-size: 0.9rem; margin-bottom: 1.5rem; }
.select-input-wrapper { max-width: 250px; margin-bottom: 1.5rem; }
.stat-dropdown-select { text-align-last: left; width: 100%; border: 1px solid var(--border-color); }
.col-span-2 { grid-column: span 2; }
.mt-1 { margin-top: 1rem; }
.calc-group-title { font-size: 0.9rem; margin-bottom: 0.5rem; }
.calc-group-subtitle { font-size: 0.8rem; color: var(--text-secondary); margin-bottom: 0.5rem; }
.outliers-text { font-size: 0.85rem; font-weight: 700; color: #ef4444; }
.font-size-95 { font-size: 0.95rem; }
.correlation-verdict-text { font-size: 0.85rem; font-weight: 700; color: var(--primary); }
.p-2 { padding: 2rem; }
.mb-15 { margin-bottom: 1.5rem; }

@media (max-width: 760px) {
    .ab-settings-grid,
    .metrics-summary-grid,
    .metrics-summary-grid-four {
        grid-template-columns: 1fr;
    }

    .col-span-2 {
        grid-column: span 1;
    }

    .select-input-wrapper {
        max-width: none;
    }
}

/* Stat Charts Styles */
.stat-chart-wrapper {
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 0.75rem;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.02);
    overflow-x: auto;
}

.stat-svg {
    width: 100%;
    height: auto;
    max-height: 260px;
    display: block;
    font-family: var(--font-main), sans-serif;
}

.chart-empty {
    text-align: center;
    padding: 2rem;
    color: var(--text-secondary);
    font-size: 0.85rem;
    font-style: italic;
}