/* ===== CSS Reset & Base Styles ===== */
:root {
    --primary-color: #0891b2;
    --primary-dark: #0e7490;
    --primary-light: #22d3ee;
    --secondary-color: #14b8a6;
    --text-color: #2d3436;
    --text-light: #636e72;
    --bg-color: #ffffff;
    --bg-light: #f0fdfa;
    --border-color: #ccfbf1;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 2px 8px rgba(0, 0, 0, 0.06);
    --border-radius: 8px;
    --border-radius-sm: 6px;
    --transition: all 0.2s ease;
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
}

ul {
    list-style: none;
}

button {
    cursor: pointer;
    border: none;
    background: none;
    font-family: inherit;
    transition: var(--transition);
}

.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 20px;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-header h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--text-light);
    line-height: 1.8;
}

/* ===== Navigation ===== */
.navbar {
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 16px 0;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color);
}

.logo-icon {
    width: 32px;
    height: 32px;
}

.brand-text {
    color: var(--text-color);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-menu a {
    font-weight: 500;
    color: var(--text-light);
    position: relative;
}

.nav-menu a:hover {
    color: var(--primary-color);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: var(--transition);
}

.nav-menu a:hover::after {
    width: 100%;
}

.btn-nav {
    padding: 10px 24px;
    background: var(--primary-color);
    color: white !important;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
}

.btn-nav:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.btn-nav::after {
    display: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    padding: 8px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--text-color);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    border: none;
    text-decoration: none;
    transition: var(--transition);
}

.btn-primary {
    background: var(--primary-color);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: white;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-light);
    border-color: var(--text-light);
}

.btn-large {
    padding: 18px 48px;
    font-size: 1.125rem;
}

/* ===== Hero Section ===== */
.hero {
    background: linear-gradient(135deg, var(--bg-color) 0%, var(--bg-light) 100%);
    color: var(--text-color);
    padding: 60px 0 80px;
    text-align: center;
}

.hero-content {
    position: relative;
    text-align: center;
    max-width: 900px;
    margin: 0 auto 60px;
}

.hero-title {
    font-size: 3rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 24px;
    color: var(--text-color);
}

.hero-title .highlight {
    display: block;
    font-size: 2rem;
    font-weight: 600;
    margin-top: 12px;
    color: var(--primary-color);
}

.hero-subtitle {
    font-size: 1.125rem;
    line-height: 1.7;
    margin-bottom: 40px;
    color: var(--text-light);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* ===== Hero Tool Interface ===== */
.hero-tool {
    max-width: 900px;
    margin: 0 auto;
}

/* Upload Area */
.hero-tool .upload-area {
    background: white;
    border: 2px dashed var(--border-color);
    border-radius: 16px;
    padding: 60px 40px;
    margin-bottom: 24px;
    cursor: pointer;
    transition: var(--transition);
}

.hero-tool .upload-area:hover {
    border-color: var(--primary-color);
    background: var(--bg-light);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.hero-tool .upload-area.drag-over {
    border-color: var(--primary-color);
    background: var(--bg-light);
}

.hero-tool .upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    color: var(--primary-color);
}

.hero-tool .upload-text {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-color);
}

.hero-tool .upload-subtext {
    color: var(--text-light);
    font-size: 1rem;
}

/* Privacy Notice */
.privacy-notice {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 32px;
    padding: 0 20px;
}

.privacy-item {
    display: flex;
    align-items: center;
    gap: 12px;
    justify-content: center;
    color: var(--text-light);
    font-size: 0.95rem;
}

.privacy-item svg {
    width: 18px;
    height: 18px;
    color: var(--primary-color);
    flex-shrink: 0;
}

/* Divider */
.divider {
    display: flex;
    align-items: center;
    margin: 32px 0;
    color: var(--text-light);
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--border-color);
}

.divider span {
    padding: 0 16px;
    font-size: 0.9rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Example Videos */
.example-videos {
    text-align: center;
}

.example-videos h3 {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 24px;
    color: var(--text-color);
}

.example-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.example-card {
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 20px;
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
}

.example-card:hover {
    border-color: var(--primary-color);
    background: var(--bg-light);
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.example-thumbnail {
    width: 100%;
    aspect-ratio: 16/9;
    background: var(--bg-light);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.example-thumbnail svg {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
}

.example-label {
    font-weight: 600;
    color: var(--text-color);
    font-size: 0.95rem;
}

/* Legacy Hero Features (kept for backward compatibility) */
.hero-cta {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 40px;
}

.hero-cta .btn-primary {
    background: var(--primary-color);
    color: white;
}

.hero-cta .btn-primary:hover {
    background: var(--primary-dark);
}

.hero-cta .btn-secondary {
    background: white;
    color: var(--text-color);
    border-color: var(--border-color);
}

.hero-cta .btn-secondary:hover {
    background: var(--bg-light);
}

.hero-features {
    display: flex;
    gap: 24px;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 48px;
}

.feature-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 18px;
    background: var(--bg-light);
    border: 1px solid var(--border-color);
    border-radius: 50px;
    font-weight: 500;
    font-size: 0.9rem;
    color: var(--text-light);
}

.feature-badge svg {
    width: 18px;
    height: 18px;
}

/* ===== Tool Section ===== */
.tool-section {
    padding: 80px 0;
    background: var(--bg-color);
}

.tool-container {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.tool-header {
    padding: 40px;
    text-align: center;
    background: var(--bg-light);
    color: var(--text-color);
    border-bottom: 1px solid var(--border-color);
}

.tool-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

.tool-header p {
    font-size: 1.125rem;
    color: var(--text-light);
}

.upload-area {
    padding: 60px 40px;
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    margin: 40px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    background: var(--bg-light);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: white;
}

.upload-area.drag-over {
    border-color: var(--primary-color);
    background: white;
}

.upload-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 20px;
    color: var(--primary-color);
}

.upload-text {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-color);
}

.upload-subtext {
    color: var(--text-light);
    font-size: 1rem;
}

.video-preview {
    padding: 40px;
    background: var(--bg-light);
}

.video-preview video {
    width: 100%;
    max-height: 500px;
    background: black;
    border-radius: var(--border-radius-sm);
}

.extraction-settings {
    padding: 40px;
}

.extraction-settings h3 {
    font-size: 1.5rem;
    margin-bottom: 24px;
    color: var(--text-color);
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-bottom: 32px;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.setting-group label {
    font-weight: 600;
    color: var(--text-color);
    font-size: 0.95rem;
}

.setting-group input,
.setting-group select {
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    font-size: 1rem;
    transition: var(--transition);
    font-family: inherit;
}

.setting-group input:focus,
.setting-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(8, 145, 178, 0.1);
}

.action-buttons {
    display: flex;
    gap: 16px;
    justify-content: flex-end;
    flex-wrap: wrap;
}

.frames-gallery {
    padding: 40px;
}

.gallery-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    flex-wrap: wrap;
    gap: 16px;
}

.gallery-header h3 {
    font-size: 1.5rem;
    color: var(--text-color);
}

.gallery-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.frames-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.frame-item {
    position: relative;
    border-radius: var(--border-radius-sm);
    overflow: hidden;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.frame-item:hover {
    border-color: var(--primary-color);
}

.frame-item img {
    width: 100%;
    height: 150px;
    object-fit: cover;
    display: block;
}

.frame-item-checkbox {
    position: absolute;
    top: 8px;
    left: 8px;
    width: 20px;
    height: 20px;
    cursor: pointer;
}

/* ===== Features Section ===== */
.features-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.feature-card {
    padding: 32px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: var(--bg-light);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.feature-icon svg {
    width: 28px;
    height: 28px;
    color: var(--primary-color);
}

.feature-card h3 {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===== How to Use Section ===== */
.how-to-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.steps-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.step-card {
    background: white;
    padding: 32px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    position: relative;
    transition: var(--transition);
}

.step-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.step-number {
    width: 56px;
    height: 56px;
    background: var(--primary-color);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 20px;
}

.step-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
}

.step-card p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 16px;
}

.step-card ul {
    list-style: disc;
    padding-left: 20px;
    color: var(--text-light);
}

.step-card li {
    margin-bottom: 8px;
    line-height: 1.6;
}

/* ===== Key Features Section ===== */
.key-features-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.key-features-list {
    display: grid;
    gap: 24px;
}

.key-feature-item {
    display: flex;
    gap: 20px;
    padding: 28px;
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.key-feature-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.key-feature-item svg {
    width: 48px;
    height: 48px;
    color: var(--primary-color);
    flex-shrink: 0;
}

.key-feature-item h4 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-color);
}

.key-feature-item p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===== Use Cases Section ===== */
.use-cases-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.use-cases-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 32px;
}

.use-case-card {
    background: white;
    padding: 32px;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.use-case-card:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.use-case-icon {
    width: 56px;
    height: 56px;
    background: var(--bg-light);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
}

.use-case-icon svg {
    width: 28px;
    height: 28px;
    color: var(--primary-color);
}

.use-case-card h3 {
    font-size: 1.375rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
}

.use-case-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===== FAQ Section ===== */
.faq-section {
    padding: 100px 0;
    background: var(--bg-color);
}

.faq-accordion {
    max-width: 900px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    margin-bottom: 16px;
    overflow: hidden;
    transition: var(--transition);
}

.faq-item:last-child {
    margin-bottom: 0;
}

.faq-item:hover {
    border-color: var(--primary-color);
    box-shadow: var(--shadow-md);
}

.faq-question {
    width: 100%;
    padding: 24px;
    background: none;
    border: none;
    text-align: left;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
    cursor: pointer;
    transition: var(--transition);
}

.faq-question span {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--text-color);
    line-height: 1.4;
    flex: 1;
}

.faq-icon {
    width: 24px;
    height: 24px;
    color: var(--primary-color);
    flex-shrink: 0;
    transition: transform 0.3s ease;
}

.faq-item.active .faq-icon {
    transform: rotate(180deg);
}

.faq-answer {
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 0.3s ease, opacity 0.3s ease, padding 0.3s ease;
}

.faq-item.active .faq-answer {
    max-height: 500px;
    opacity: 1;
    padding: 0 24px 24px 24px;
}

.faq-answer p {
    color: var(--text-light);
    line-height: 1.8;
    margin: 0;
}

.faq-item.active .faq-question {
    background: var(--bg-light);
}

/* ===== CTA Section ===== */
.cta-section {
    padding: 100px 0;
    background: var(--bg-light);
    text-align: center;
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
}

.cta-content h2 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text-color);
}

.cta-content p {
    font-size: 1.125rem;
    margin-bottom: 32px;
    color: var(--text-light);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.cta-content .btn-primary {
    background: var(--primary-color);
    color: white;
    margin-bottom: 24px;
}

.cta-content .btn-primary:hover {
    background: var(--primary-dark);
}

.cta-note {
    font-size: 1rem;
    color: var(--text-light);
}

/* ===== Footer ===== */
.footer {
    background: var(--bg-color);
    color: var(--text-color);
    padding: 60px 0 24px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .nav-brand {
    margin-bottom: 16px;
}

.footer-brand .brand-text {
    color: var(--text-color);
}

.footer-brand p {
    color: var(--text-light);
    line-height: 1.8;
}

.footer-links h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: 16px;
    color: var(--text-color);
}

.footer-links ul {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.footer-links a {
    color: var(--text-light);
    transition: var(--transition);
}

.footer-links a:hover {
    color: var(--primary-color);
}

.footer-bottom {
    padding-top: 24px;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-light);
}

/* ===== Responsive Design ===== */
@media (max-width: 1024px) {
    .hero-title {
        font-size: 3rem;
    }

    .hero-title .highlight {
        font-size: 2rem;
    }

    .section-header h2 {
        font-size: 2rem;
    }

    /* FAQ Responsive */
    .faq-question {
        padding: 20px;
    }

    .faq-question span {
        font-size: 1rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 20px 20px 20px;
    }

    /* Hero Tool Responsive */
    .example-grid {
        grid-template-columns: repeat(3, 1fr);
        gap: 16px;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background: white;
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: 24px;
        transition: right 0.3s ease;
        box-shadow: var(--shadow-lg);
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-toggle {
        display: flex;
        z-index: 1001;
    }

    .nav-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .nav-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero {
        padding: 60px 0 40px;
    }

    .hero-title {
        font-size: 2.25rem;
    }

    .hero-title .highlight {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .hero-cta {
        flex-direction: column;
        align-items: stretch;
    }

    .hero-features {
        flex-direction: column;
        align-items: center;
    }

    .feature-badge {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }

    /* Hero Tool Responsive */
    .hero-tool .upload-area {
        padding: 40px 20px;
        margin: 20px;
    }

    .privacy-notice {
        padding: 0 10px;
    }

    .example-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .example-card {
        padding: 16px;
    }

    .tool-section,
    .features-section,
    .how-to-section,
    .key-features-section,
    .use-cases-section,
    .faq-section {
        padding: 60px 0;
    }

    .upload-area {
        padding: 40px 20px;
        margin: 20px;
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .action-buttons {
        flex-direction: column;
    }

    .action-buttons .btn {
        width: 100%;
        justify-content: center;
    }

    .gallery-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .gallery-actions {
        width: 100%;
    }

    .gallery-actions .btn {
        flex: 1;
    }

    .frames-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    .section-header h2 {
        font-size: 1.75rem;
    }

    .section-header p {
        font-size: 1rem;
    }

    .cta-content h2 {
        font-size: 2rem;
    }

    .cta-content p {
        font-size: 1.125rem;
    }

    .footer-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 1.875rem;
    }

    .hero-title .highlight {
        font-size: 1.5rem;
    }

    .btn {
        padding: 12px 24px;
        font-size: 0.95rem;
    }

    .feature-card,
    .step-card,
    .use-case-card {
        padding: 32px 24px;
    }

    .frames-grid {
        grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
        gap: 12px;
    }

    /* FAQ Mobile Responsive */
    .faq-question {
        padding: 16px;
    }

    .faq-question span {
        font-size: 0.95rem;
    }

    .faq-item.active .faq-answer {
        padding: 0 16px 16px 16px;
    }
}

/* ===== Utility Classes ===== */
.text-center {
    text-align: center;
}

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mt-4 { margin-top: 32px; }

.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }
.mb-4 { margin-bottom: 32px; }