:root {
    --bg-color: #F4F4F0;
    --surface: #FFFFFF;
    --ink: #101312;
    --muted: #5C605B;
    --primary: #00C8A0;
    --signal: #FF4D2E;
    --divider: #E1E1DB;
    
    --radius: 4px;
    --space-section: 120px;
    --transition: 150ms ease-out;
}

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&family=Space+Grotesk:wght@500;700&display=swap');

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

body {
    font-family: "Noto Sans SC", -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-color);
    color: var(--ink);
    line-height: 1.7;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

h1, h2, h3, h4, h5, h6, .display-font {
    font-family: "Space Grotesk", "Noto Sans SC", sans-serif;
    letter-spacing: -0.03em;
    color: var(--ink);
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 32px;
}

/* Header */
header {
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--divider);
    padding: 24px 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-container {
    display: flex;
    align-items: center;
    text-decoration: none;
    color: var(--ink);
    font-weight: 700;
    font-size: 20px;
    font-family: "Space Grotesk", sans-serif;
    letter-spacing: -0.03em;
}

.logo-svg {
    height: 32px;
    margin-right: 12px;
}

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

nav.main-nav a {
    color: var(--ink);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition);
}

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

.cta-button {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background-color: var(--primary);
    color: var(--ink);
    padding: 12px 28px;
    border-radius: var(--radius);
    text-decoration: none;
    font-weight: 700;
    transition: background-color var(--transition), transform var(--transition);
    border: none;
    cursor: pointer;
}

.cta-button:hover {
    background-color: #00E5B7;
}

/* Hero Section */
.hero {
    padding: var(--space-section) 0;
    border-bottom: 1px solid var(--divider);
}

.hero-grid {
    display: grid;
    grid-template-columns: 7fr 5fr;
    gap: 64px;
    align-items: center;
}

.hero h1 {
    font-size: clamp(40px, 7vw, 96px);
    line-height: 1.05;
    margin-bottom: 32px;
    font-weight: 700;
}

.hero p {
    font-size: 20px;
    color: var(--muted);
    margin-bottom: 48px;
    max-width: 90%;
}

/* Sections General */
section {
    padding: var(--space-section) 0;
    border-bottom: 1px solid var(--divider);
}

.section-title {
    font-size: clamp(32px, 4vw, 48px);
    margin-bottom: 64px;
    font-weight: 500;
}

/* Grid Layouts */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 64px;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 64px;
}

/* Cards (Hairline styling) */
.card {
    background: var(--surface);
    border: 1px solid var(--divider);
    border-radius: var(--radius);
    padding: 48px;
    transition: border-color var(--transition);
}

.card:hover {
    border-color: var(--ink);
}

.card h3 {
    font-size: 24px;
    margin-bottom: 16px;
    font-weight: 500;
}

.card p {
    color: var(--muted);
}

/* Extension Resources */
.extension-resources {
    background: var(--surface);
    border: 1px solid var(--divider);
    padding: 32px 48px;
    border-radius: var(--radius);
    margin-top: 64px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.extension-resources a {
    color: var(--ink);
    font-weight: 500;
    text-decoration: none;
    border-bottom: 1px solid var(--ink);
    transition: color var(--transition), border-color var(--transition);
}
.extension-resources a:hover {
    color: var(--primary);
    border-color: var(--primary);
}

/* Pricing */
.pricing-card {
    background: var(--surface);
    border: 1px solid var(--divider);
    padding: 56px 48px;
    border-radius: var(--radius);
    display: flex;
    flex-direction: column;
}

.pricing-card.popular {
    border-color: var(--ink);
    position: relative;
}

.signal-badge {
    position: absolute;
    top: -12px;
    right: 48px;
    background: var(--signal);
    color: #fff;
    font-size: 12px;
    font-weight: 700;
    padding: 4px 12px;
    border-radius: var(--radius);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.price-metric {
    font-size: clamp(48px, 5vw, 72px);
    font-family: "Space Grotesk", sans-serif;
    font-weight: 700;
    line-height: 1;
    margin: 24px 0 16px;
    color: var(--ink);
}

.price-metric span {
    font-size: 18px;
    color: var(--muted);
    font-weight: 400;
}

.pricing-features {
    list-style: none;
    margin: 40px 0;
    flex-grow: 1;
}

.pricing-features li {
    margin-bottom: 16px;
    color: var(--muted);
    display: flex;
    align-items: flex-start;
}

.pricing-features li::before {
    content: "—";
    color: var(--ink);
    margin-right: 12px;
    font-weight: bold;
}

.pricing-card .cta-button {
    width: 100%;
}

/* FAQ & Testimonials */
.faq-grid, .testi-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 32px;
    max-width: 800px;
}

.faq-item, .testi-card {
    border-bottom: 1px solid var(--divider);
    padding-bottom: 32px;
}

.faq-item:last-child, .testi-card:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.faq-item h4 {
    font-size: 20px;
    margin-bottom: 12px;
    font-weight: 500;
}

.testi-card {
    font-size: 20px;
    color: var(--ink);
    line-height: 1.5;
}

.testi-author {
    margin-top: 16px;
    font-size: 14px;
    color: var(--muted);
}

/* Footer */
footer {
    padding: var(--space-section) 0 64px;
    background: var(--bg-color);
}

.footer-inner {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 64px;
}

.footer-links {
    display: flex;
    gap: 48px;
}

.footer-links a {
    color: var(--muted);
    text-decoration: none;
    transition: color var(--transition);
}

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

.copyright {
    color: var(--muted);
    font-size: 14px;
}

/* Animations */
.fade-up {
    animation: fadeUp 0.6s var(--transition) forwards;
}

@keyframes fadeUp {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Media Queries */
@media (max-width: 1024px) {
    .hero-grid { grid-template-columns: 1fr; }
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .footer-inner { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 768px) {
    :root { --space-section: 80px; }
    .grid-3, .grid-2 { grid-template-columns: 1fr; gap: 32px; }
    nav.main-nav { display: none; /* simple mobile fallback */ }
    .hero h1 { font-size: 48px; }
    .pricing-card { padding: 32px; }
}


/* Floating Action Button */
.fab-container {
    position: fixed;
    bottom: 40px;
    right: 40px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.fab-button {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--ink);
    color: var(--surface);
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    transition: transform var(--transition), background-color var(--transition);
    cursor: pointer;
    border: none;
}
.fab-button:hover {
    transform: translateY(-4px);
    background-color: var(--primary);
}
.fab-button svg {
    width: 20px;
    height: 20px;
    fill: currentColor;
}

/* Next Article Footer */
.next-article-nav {
    margin-top: 64px;
    padding-top: 32px;
    border-top: 1px solid var(--divider);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.next-article-nav a {
    color: var(--ink);
    text-decoration: none;
    font-weight: 500;
    font-size: 18px;
    display: flex;
    align-items: center;
    gap: 12px;
    transition: color var(--transition);
}
.next-article-nav a:hover {
    color: var(--primary);
}