.hv-story {
        --story-green: #23ac39;
        --story-green-dark: #1e8c30;
        --story-green-light: #e8f5e9;
        --story-green-soft: #d4edda;
        --story-accent: #f57c00;
        --story-accent-light: #fff3e0;
        --story-dark: #1a1a1a;
        --story-gray: #555;
        --story-light-gray: #888;
        --story-border: #e8e8e8;
        --story-bg: #fafbfc;
        --story-white: #ffffff;
        --story-radius: 16px;
        --story-shadow: 0 8px 32px rgba(35, 172, 57, 0.08);
        --story-shadow-hover: 0 12px 40px rgba(35, 172, 57, 0.14);
        font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
        background: var(--story-bg);
        color: var(--story-dark);
        line-height: 1.75;
        font-size: 16px;
        max-width: 880px;
        margin: 0 auto;
        padding: 48px 28px;
        position: relative;
    }

    /* Hero Header */
    .hv-story .story-hero {
        position: relative;
        text-align: center;
        padding: 48px 32px 40px;
        margin-bottom: 48px;
        background: linear-gradient(135deg, var(--story-green-light) 0%, var(--story-white) 50%, var(--story-accent-light) 100%);
        border-radius: var(--story-radius);
        overflow: hidden;
    }
    .hv-story .story-hero::before {
        content: "";
        position: absolute;
        top: 0; left: 0; right: 0;
        height: 5px;
        background: linear-gradient(90deg, var(--story-green), var(--story-accent), var(--story-green));
    }
    .hv-story .story-hero h1 {
        font-size: 2.2rem;
        font-weight: 800;
        color: var(--story-dark);
        line-height: 1.25;
        margin-bottom: 16px;
        letter-spacing: -0.5px;
    }
    .hv-story .story-hero h1 span {
        color: var(--story-green);
        position: relative;
    }
    .hv-story .story-hero h1 span::after {
        content: "";
        position: absolute;
        bottom: 2px; left: 0; right: 0;
        height: 8px;
        background: rgba(35, 172, 57, 0.15);
        border-radius: 4px;
        z-index: -1;
    }
    .hv-story .story-hero .hero-sub {
        font-size: 1.05rem;
        color: var(--story-gray);
        max-width: 640px;
        margin: 0 auto;
        line-height: 1.7;
    }
    .hv-story .story-hero .hero-tags {
        margin-top: 20px;
        display: flex;
        justify-content: center;
        gap: 10px;
        flex-wrap: wrap;
    }
    .hv-story .story-hero .hero-tags span {
        display: inline-block;
        padding: 6px 16px;
        background: var(--story-white);
        border: 1.5px solid var(--story-green);
        color: var(--story-green);
        border-radius: 20px;
        font-size: 0.8rem;
        font-weight: 600;
        letter-spacing: 0.5px;
    }

    /* Section Cards */
    .hv-story .story-section {
        background: var(--story-white);
        border-radius: var(--story-radius);
        padding: 36px 32px;
        margin-bottom: 32px;
        box-shadow: var(--story-shadow);
        transition: box-shadow 0.3s ease, transform 0.3s ease;
        position: relative;
        overflow: hidden;
    }
    .hv-story .story-section:hover {
        box-shadow: var(--story-shadow-hover);
        transform: translateY(-2px);
    }
    .hv-story .story-section::before {
        content: "";
        position: absolute;
        top: 0; left: 0;
        width: 5px;
        height: 100%;
        background: linear-gradient(180deg, var(--story-green), var(--story-green-dark));
    }

    .hv-story .section-header {
        display: flex;
        align-items: flex-start;
        gap: 16px;
        margin-bottom: 20px;
    }
    .hv-story .section-num {
        flex-shrink: 0;
        width: 48px;
        height: 48px;
        background: linear-gradient(135deg, var(--story-green), var(--story-green-dark));
        color: white;
        border-radius: 14px;
        display: flex;
        align-items: center;
        justify-content: center;
        font-size: 1.3rem;
        font-weight: 800;
        box-shadow: 0 4px 12px rgba(35, 172, 57, 0.3);
    }
    .hv-story .section-title-group h2 {
        font-size: 1.45rem;
        color: var(--story-dark);
        margin: 0 0 6px 0;
        font-weight: 700;
        line-height: 1.3;
    }
    .hv-story .section-title-group .section-tag {
        font-size: 0.78rem;
        color: var(--story-green);
        font-weight: 600;
        text-transform: uppercase;
        letter-spacing: 1px;
    }

    .hv-story .story-section p {
        margin-bottom: 14px;
        color: var(--story-gray);
        text-align: justify;
    }
    .hv-story .story-section p:last-child {
        margin-bottom: 0;
    }

    /* Sub-headings inside sections */
    .hv-story .story-section h3 {
        font-size: 1.1rem;
        color: var(--story-dark);
        margin: 24px 0 10px 0;
        padding-left: 14px;
        border-left: 3px solid var(--story-accent);
        font-weight: 700;
    }

    /* Formula Box */
    .hv-story .formula-card {
        background: linear-gradient(135deg, #f0f7f2 0%, var(--story-green-light) 100%);
        border: 2px solid var(--story-green-soft);
        border-radius: 12px;
        padding: 24px 28px;
        margin: 20px 0;
        text-align: center;
        position: relative;
    }
    .hv-story .formula-card::before {
        content: "PHYSICS";
        position: absolute;
        top: -10px;
        left: 20px;
        background: var(--story-green);
        color: white;
        font-size: 0.65rem;
        font-weight: 700;
        padding: 3px 10px;
        border-radius: 4px;
        letter-spacing: 1px;
    }
    .hv-story .formula-card div {
        font-family: "Courier New", monospace;
        font-size: 1.25rem;
        color: var(--story-dark);
        font-weight: 700;
        line-height: 2;
    }

    /* Highlight Box */
    .hv-story .insight-box {
        background: var(--story-accent-light);
        border-left: 4px solid var(--story-accent);
        padding: 18px 22px;
        margin: 20px 0;
        border-radius: 0 12px 12px 0;
        position: relative;
    }
    .hv-story .insight-box::before {
        content: "💡";
        position: absolute;
        top: -12px;
        left: 16px;
        background: var(--story-white);
        padding: 2px 6px;
        border-radius: 50%;
        font-size: 1.1rem;
    }
    .hv-story .insight-box strong {
        color: var(--story-accent);
    }

    /* Figures */
    .hv-story .story-figure {
        margin: 28px 0;
        text-align: center;
    }
    .hv-story .story-figure .img-frame {
        display: inline-block;
        padding: 12px;
        background: var(--story-white);
        border: 2px solid var(--story-border);
        border-radius: 16px;
        box-shadow: 0 6px 24px rgba(0,0,0,0.06);
        transition: transform 0.3s ease, box-shadow 0.3s ease;
    }
    .hv-story .story-figure .img-frame:hover {
        transform: translateY(-4px) scale(1.01);
        box-shadow: 0 12px 32px rgba(35, 172, 57, 0.12);
        border-color: var(--story-green-soft);
    }
    .hv-story .story-figure img {
        width: 500px;
        height: 500px;
        object-fit: contain;
        border-radius: 10px;
        display: block;
        background: #f9fafb;
    }
    .hv-story .story-figure figcaption {
        margin-top: 14px;
        font-size: 0.88rem;
        color: var(--story-light-gray);
        font-style: italic;
        max-width: 500px;
        margin-left: auto;
        margin-right: auto;
        line-height: 1.5;
    }
    .hv-story .story-figure .fig-badge {
        display: inline-block;
        margin-bottom: 10px;
        padding: 4px 12px;
        background: var(--story-green);
        color: white;
        font-size: 0.7rem;
        font-weight: 700;
        border-radius: 20px;
        letter-spacing: 0.5px;
        text-transform: uppercase;
    }

    /* Tables */
    .hv-story .story-table-wrap {
        overflow-x: auto;
        margin: 24px 0;
        border-radius: 12px;
        box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    }
    .hv-story .story-table {
        width: 100%;
        border-collapse: separate;
        border-spacing: 0;
        font-size: 0.92rem;
        min-width: 600px;
    }
    .hv-story .story-table thead th {
        background: linear-gradient(135deg, var(--story-green), var(--story-green-dark));
        color: white;
        padding: 14px 16px;
        text-align: left;
        font-weight: 600;
        font-size: 0.85rem;
        text-transform: uppercase;
        letter-spacing: 0.5px;
    }
    .hv-story .story-table thead th:first-child {
        border-radius: 12px 0 0 0;
    }
    .hv-story .story-table thead th:last-child {
        border-radius: 0 12px 0 0;
    }
    .hv-story .story-table tbody td {
        padding: 14px 16px;
        border-bottom: 1px solid var(--story-border);
        color: var(--story-gray);
        background: var(--story-white);
    }
    .hv-story .story-table tbody tr:last-child td:first-child {
        border-radius: 0 0 0 12px;
    }
    .hv-story .story-table tbody tr:last-child td:last-child {
        border-radius: 0 0 12px 0;
    }
    .hv-story .story-table tbody tr:nth-child(even) td {
        background: var(--story-green-light);
    }
    .hv-story .story-table tbody tr:hover td {
        background: var(--story-green-soft);
        transition: background 0.2s;
    }
    .hv-story .story-table td strong {
        color: var(--story-dark);
    }

    /* Mono block for chain */
    .hv-story .chain-block {
        background: linear-gradient(90deg, #f8f9fa, #f0f7f2);
        border: 1.5px dashed var(--story-green-soft);
        padding: 16px 20px;
        margin: 16px 0;
        border-radius: 10px;
        font-family: "SF Mono", "Courier New", monospace;
        font-size: 0.9rem;
        color: var(--story-dark);
        line-height: 1.8;
    }

    /* Conclusion Special */
    .hv-story .conclusion-section {
        background: linear-gradient(135deg, var(--story-green-light) 0%, var(--story-white) 100%);
        border: 2px solid var(--story-green);
        border-radius: var(--story-radius);
        padding: 36px 32px;
        position: relative;
        overflow: visible;
    }
    .hv-story .conclusion-section::before {
        display: none;
    }
    .hv-story .conclusion-section .section-header {
        justify-content: center;
        margin-bottom: 24px;
    }
    .hv-story .conclusion-section .section-title-group {
        text-align: center;
    }
    .hv-story .conclusion-section .section-title-group h2 {
        font-size: 1.6rem;
    }
    .hv-story .conclusion-section p {
        text-align: justify;
    }
    .hv-story .conclusion-section strong {
        color: var(--story-green-dark);
    }

    /* Responsive */
    @media (max-width: 768px) {
        .hv-story {
            padding: 24px 16px;
        }
        .hv-story .story-hero {
            padding: 32px 20px 28px;
        }
        .hv-story .story-hero h1 {
            font-size: 1.6rem;
        }
        .hv-story .story-section {
            padding: 24px 20px;
        }
        .hv-story .section-header {
            gap: 12px;
        }
        .hv-story .section-num {
            width: 40px;
            height: 40px;
            font-size: 1.1rem;
        }
        .hv-story .section-title-group h2 {
            font-size: 1.2rem;
        }
        .hv-story .story-figure img {
            width: 100%;
            max-width: 500px;
            height: auto;
            max-height: 500px;
        }
        .hv-story .story-table-wrap {
            border-radius: 8px;
        }
    }

    @media (max-width: 480px) {
        .hv-story .story-hero h1 {
            font-size: 1.35rem;
        }
        .hv-story .story-hero .hero-tags span {
            font-size: 0.7rem;
            padding: 4px 10px;
        }
    }