* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    background: #fff;
    color: #222;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    line-height: 1.7;
}

a {
    color: inherit;
    text-decoration: none;
}

.hero {
    min-height: 600px;
    display: grid;
    grid-template-columns: 0.85fr 1.15fr;
    align-items: center;
    gap: 3rem;
    padding-top: 4rem;
    padding-bottom: 4rem;
}

.hero-copy {
    padding-bottom: 1rem;
}

.eyebrow {
    margin: 0 0 0.65rem;
    color: #4f8a5b;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.12em;
}

.hero h1 {
    max-width: 620px;
    margin: 0;
    font-size: clamp(2.4rem, 5vw, 4.2rem);
    line-height: 1.08;
    font-weight: 600;
    letter-spacing: -0.035em;
}

.hero-lead {
    max-width: 540px;
    margin: 1.5rem 0 0;
    color: #666;
    font-size: 1.05rem;
}

.introduction-back-link {
    display: inline-block;
    margin-top: 2.25rem;
    color: var(--site-accent);
    font-size: 0.9rem;
    text-decoration: none;
}

    .introduction-back-link:hover {
        color: #0d6efd;
        text-decoration: underline;
    }

.hero-image-wrap {
    display: flex;
    align-items: center;
    justify-content: center;
}

.hero-image {
    display: block;
    width: 100%;
    max-width: 620px;
    height: auto;
}

.section {
    padding: 6rem 0;
}

.section-soft {
    background: #f7f7f7;
}

.section-heading {
    max-width: 850px;
    margin-bottom: 2.5rem;
}

.section-number {
    margin: 0 0 0.3rem;
    color: #aaa;
    font-family: Consolas, "Courier New", monospace;
    font-size: 0.8rem;
    font-weight: 600;
}

.section-heading h2 {
    margin: 0;
    font-size: clamp(1.9rem, 3.5vw, 3rem);
    line-height: 1.18;
    font-weight: 600;
    letter-spacing: -0.025em;
}

.content {
    max-width: 780px;
    color: #444;
    font-size: 1rem;
}

.content p {
    margin: 0 0 1.35rem;
}

.content ul {
    margin: 1.5rem 0 2rem;
    padding-left: 1.25rem;
}

.content li {
    margin-bottom: 0.45rem;
}

.toolbox-message {
    max-width: 900px;
    color: #444;
    font-size: 1.05rem;
}

.toolbox-message > p {
    max-width: 780px;
}

.three-step {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-top: 2.75rem;
}

.step {
    padding: 1.5rem;
    border: 1px solid #dedede;
    border-radius: 5px;
    background: #fff;
}

.step-number {
    display: block;
    margin-bottom: 0.8rem;
    color: #4f8a5b;
    font-family: Consolas, "Courier New", monospace;
    font-size: 0.75rem;
    font-weight: 700;
}

.step h3 {
    margin: 0;
    font-size: 1.05rem;
    font-weight: 600;
}

.utility-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-top: 2rem;
}

.utility-card {
    min-height: 145px;
    padding: 1.5rem;
    border: 1px solid #dedede;
    border-radius: 5px;
    background: #fff;
}

.utility-card h3 {
    margin: 0 0 0.5rem;
    font-size: 1.05rem;
    font-weight: 600;
}

.utility-card p {
    margin: 0;
    color: #666;
    font-size: 0.9rem;
}

.after-grid {
    max-width: 780px;
    margin: 1.5rem 0 0;
    color: #444;
}

.three-phrases {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 2rem;
}

.three-phrases span {
    padding: 0.55rem 0.9rem;
    border: 1px solid #d9d9d9;
    border-radius: 999px;
    background: #fff;
    color: #4f8a5b;
    font-size: 0.9rem;
}

blockquote {
    max-width: 780px;
    margin: 2rem 0;
    padding: 1.25rem 1.5rem;
    border-left: 3px solid #4f8a5b;
    background: #f7f7f7;
    color: #333;
    font-size: 1.1rem;
}

.final-section {
    padding: 7rem 0;
    background: #4f8a5b;
    color: #fff;
}

.final-content {
    text-align: center;
}

.final-section .eyebrow {
    color: #dcefe0;
}

.final-section h2 {
    margin: 0 0 2rem;
    font-size: clamp(2.2rem, 5vw, 4rem);
    line-height: 1.1;
    font-weight: 600;
    letter-spacing: -0.03em;
}

.final-section p {
    margin: 0.3rem 0;
    color: #eef7f0;
    font-size: 1.05rem;
}

.closing {
    margin-top: 2.5rem;
    font-size: 1.15rem;
    line-height: 1.7;
}

/* Dark mode */

[data-theme="dark"] body {
    background: #121212;
    color: #e5e5e5;
}

[data-theme="dark"] .hero-lead {
    color: #b5b5b5;
}

[data-theme="dark"] .section-soft {
    background: #1a1a1a;
}

[data-theme="dark"] .section-number {
    color: #888;
}

[data-theme="dark"] .content {
    color: #d0d0d0;
}

[data-theme="dark"] .toolbox-message {
    color: #d0d0d0;
}

[data-theme="dark"] .step {
    border-color: #444;
    background: #1e1e1e;
}

[data-theme="dark"] .utility-card {
    border-color: #444;
    background: #1e1e1e;
}

    [data-theme="dark"] .utility-card p {
        color: #aaa;
    }

[data-theme="dark"] .after-grid {
    color: #d0d0d0;
}

[data-theme="dark"] .three-phrases span {
    border-color: #444;
    background: #1e1e1e;
    color: #6fa77a;
}

[data-theme="dark"] blockquote {
    border-left-color: #4f8a5b;
    background: #1a1a1a;
    color: #d8d8d8;
}

[data-theme="dark"] .final-section {
    background: #4f8a5b;
    color: #fff;
}

    [data-theme="dark"] .final-section .eyebrow {
        color: #dcefe0;
    }

    [data-theme="dark"] .final-section p {
        color: #eef7f0;
    }

[data-theme="dark"] .hero-image {
    opacity: 0.88;
}

@media (max-width: 800px) {
    .hero {
        grid-template-columns: 1fr;
        padding-top: 3rem;
        padding-bottom: 3rem;
    }

    .hero-image-wrap {
        order: -1;
    }

    .hero-image {
        max-width: 520px;
    }

    .three-step,
    .utility-grid {
        grid-template-columns: 1fr;
    }

    .section {
        padding: 4.5rem 0;
    }
}

@media (max-width: 520px) {
    .hero h1 {
        font-size: 2.35rem;
    }

    .hero-lead {
        font-size: 0.95rem;
    }

    .section-heading h2 {
        font-size: 1.85rem;
    }
}