:root {
    --primary-color: #4a69bd;
    --secondary-color: #6a89cc;
    --accent-color: #f6b93b;
    --text-color: #34495e;
    --heading-color: #2c3e50;
    --bg-light: #f8f9fa;
    --bg-white: #ffffff;
    --border-color: #e9ecef;
    --success-color: #2ecc71;
    --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 10px rgba(0,0,0,0.08);
    --border-radius: 8px;
    --font-main: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --container-width: 1140px;
    --spacing-unit: 1rem;
}

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

html {
    scroll-behavior: smooth;
    font-size: 100%;
}

body {
    font-family: var(--font-main);
    color: var(--text-color);
    line-height: 1.7;
    background-color: var(--bg-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

a {
    color: var(--primary-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

.nav {
    position: sticky;
    top: 0;
    z-index: 10;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
    padding: 0 calc(var(--spacing-unit) * 2);
    background-color: rgba(255,255,255,0.96);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    backdrop-filter: blur(12px);
}

.brand {
    color: var(--heading-color);
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.02em;
}

.brand span {
    color: var(--primary-color);
}

.brand:hover {
    color: var(--heading-color);
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 22px;
    color: var(--text-color);
    font-size: 0.98rem;
}

.nav-links a:not(.button) {
    color: var(--text-color);
    font-weight: 500;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 calc(var(--spacing-unit) * 1.5);
}

.hero {
    padding: calc(var(--spacing-unit) * 5) 0 calc(var(--spacing-unit) * 4);
    text-align: center;
    background: linear-gradient(135deg, #eef3ff 0%, #ffffff 48%, #fff8e7 100%);
    border-bottom: 1px solid var(--border-color);
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    background-color: rgba(74,105,189,0.09);
    border: 1px solid rgba(74,105,189,0.16);
    border-radius: 999px;
    padding: 7px 14px;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    margin-bottom: calc(var(--spacing-unit) * 1.25);
}

h1,
h2,
h3 {
    color: var(--heading-color);
    line-height: 1.3;
    font-weight: 700;
}

h1 {
    max-width: 940px;
    margin: 0 auto var(--spacing-unit);
    font-size: clamp(2.25rem, 5vw, 3.3rem);
}

h2 {
    text-align: center;
    font-size: clamp(1.8rem, 4vw, 2.5rem);
    margin-bottom: calc(var(--spacing-unit) * 2.75);
}

h3 {
    font-size: 1.35rem;
    margin-bottom: calc(var(--spacing-unit) * 0.75);
}

p {
    margin-bottom: var(--spacing-unit);
    font-size: 1rem;
    color: var(--text-color);
}

.lead {
    max-width: 820px;
    margin: 0 auto calc(var(--spacing-unit) * 2);
    color: #555;
    font-size: 1.15rem;
}

.actions {
    display: flex;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    gap: 14px;
    margin-top: calc(var(--spacing-unit) * 1.5);
}

.button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 48px;
    padding: 0 26px;
    border-radius: var(--border-radius);
    font-weight: 700;
    text-decoration: none;
    border: 2px solid transparent;
    box-shadow: var(--shadow-sm);
}

.button:hover {
    text-decoration: none;
}

.button.primary {
    color: #fff;
    background-color: var(--primary-color);
    border-color: var(--primary-color);
}

.button.primary:hover {
    background-color: var(--secondary-color);
    border-color: var(--secondary-color);
    color: #fff;
}

.button.secondary {
    color: var(--primary-color);
    background-color: #fff;
    border-color: var(--primary-color);
}

.proof {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: calc(var(--spacing-unit) * 1.5);
    margin-top: calc(var(--spacing-unit) * 3);
}

.proof div {
    text-align: left;
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    padding: calc(var(--spacing-unit) * 1.4);
}

.proof strong {
    display: block;
    color: var(--primary-color);
    font-size: 1.75rem;
    line-height: 1.1;
    margin-bottom: 6px;
}

.proof span {
    color: #555;
}

section {
    padding: calc(var(--spacing-unit) * 4) 0;
}

main section:nth-of-type(odd) {
    background-color: var(--bg-light);
}

.section-lead {
    max-width: 780px;
    margin: calc(var(--spacing-unit) * -1.5) auto calc(var(--spacing-unit) * 2.5);
    color: #555;
    text-align: center;
    font-size: 1.05rem;
}

.grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: calc(var(--spacing-unit) * 1.5);
}

.grid.two {
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.card {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    padding: calc(var(--spacing-unit) * 1.75);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
}

.card h3 {
    color: var(--primary-color);
}

.card p {
    color: #555;
    margin-bottom: 0;
}

.intent-box {
    background-color: #ffffff;
    border-left: 5px solid var(--accent-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    padding: calc(var(--spacing-unit) * 2);
}

.intent-box h2 {
    text-align: left;
    color: var(--heading-color);
    margin-bottom: var(--spacing-unit);
}

.intent-box p {
    color: #555;
}

.intent-box ul,
.article-guide ul {
    margin: var(--spacing-unit) 0 0 calc(var(--spacing-unit) * 1.25);
}

.intent-box li,
.article-guide li {
    margin-bottom: calc(var(--spacing-unit) * 0.5);
}

.article-guide {
    max-width: 940px;
}

.article-guide h2 {
    margin-bottom: calc(var(--spacing-unit) * 1.75);
}

.article-guide article {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    padding: calc(var(--spacing-unit) * 2);
    margin-bottom: calc(var(--spacing-unit) * 1.5);
}

.article-guide article h3 {
    color: var(--primary-color);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: calc(var(--spacing-unit) * 0.75);
    margin-bottom: var(--spacing-unit);
}

.article-guide article p:last-child,
.article-guide article ul:last-child {
    margin-bottom: 0;
}

.comparison-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    overflow: hidden;
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.comparison-table th,
.comparison-table td {
    text-align: left;
    vertical-align: top;
    padding: calc(var(--spacing-unit) * 1.2);
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    color: var(--heading-color);
    background-color: #eef3ff;
    font-weight: 700;
}

.comparison-table td {
    color: #555;
}

.comparison-table tr:last-child td {
    border-bottom: 0;
}

.faq {
    max-width: 860px;
}

.faq details {
    background-color: var(--bg-white);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-unit);
    overflow: hidden;
    transition: box-shadow 0.2s ease;
}

.faq details[open] {
    box-shadow: var(--shadow-md);
}

.faq summary {
    color: var(--heading-color);
    cursor: pointer;
    font-weight: 700;
    list-style: none;
    padding: calc(var(--spacing-unit) * 1.25) calc(var(--spacing-unit) * 1.5);
    position: relative;
}

.faq summary::-webkit-details-marker {
    display: none;
}

.faq summary::after {
    content: "+";
    color: var(--primary-color);
    font-size: 1.5rem;
    position: absolute;
    right: calc(var(--spacing-unit) * 1.5);
    top: 50%;
    transform: translateY(-50%);
}

.faq details[open] summary::after {
    content: "-";
}

.faq p {
    color: #555;
    padding: 0 calc(var(--spacing-unit) * 1.5) calc(var(--spacing-unit) * 1.25);
    margin: 0;
}

.cluster {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    justify-content: center;
}

.cluster a {
    color: var(--primary-color);
    background-color: #fff;
    border: 1px solid var(--border-color);
    border-radius: 999px;
    box-shadow: var(--shadow-sm);
    padding: 8px 14px;
    font-weight: 600;
}

.cluster a:hover {
    color: var(--secondary-color);
    text-decoration: none;
}

.final-cta {
    text-align: center;
    padding: calc(var(--spacing-unit) * 4) 0;
    background-color: var(--primary-color);
}

.final-cta .button.primary {
    color: var(--primary-color);
    background-color: #fff;
    border-color: #fff;
}

footer {
    background-color: var(--heading-color);
    color: rgba(255,255,255,0.75);
    text-align: center;
    padding: calc(var(--spacing-unit) * 2);
    font-size: 0.9rem;
}

footer a {
    color: #fff;
}

@media (max-width: 850px) {
    .nav {
        padding: 14px 20px;
        align-items: flex-start;
        flex-direction: column;
    }

    .nav-links {
        width: 100%;
        flex-wrap: wrap;
        gap: 12px;
    }

    .nav-links a:not(.button) {
        display: none;
    }

    .proof,
    .grid,
    .grid.two {
        grid-template-columns: 1fr;
    }

    section {
        padding: calc(var(--spacing-unit) * 3) 0;
    }

    .hero {
        padding-top: calc(var(--spacing-unit) * 3.5);
    }
}