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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Ubuntu, Cantarell, sans-serif;
    line-height: 1.6;
    color: #1f2933;
    background: linear-gradient(135deg, #0f766e 0%, #1e3a8a 100%);
    min-height: 100vh;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    background: #ffffff;
    box-shadow: 0 25px 70px rgba(0, 0, 0, 0.35);
}

/* Header */

header {
    background: linear-gradient(135deg, #0f766e 0%, #134e4a 100%);
    color: white;
    text-align: center;
    padding: 3.5rem 2rem;
}

header h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    letter-spacing: 0.5px;
}

.subtitle {
    font-size: 1.25rem;
    opacity: 0.95;
    max-width: 900px;
    margin: 0 auto;
}

/* Hero */

.hero {
    padding: 4.5rem 2rem;
    background: linear-gradient(to bottom, #f0fdfa, #ffffff);
    text-align: center;
}

.hero-content h2 {
    font-size: 2.3rem;
    color: #0f172a;
    margin-bottom: 1.5rem;
}

.hero-content p {
    font-size: 1.2rem;
    color: #334155;
    margin-bottom: 2.5rem;
    max-width: 850px;
    margin-left: auto;
    margin-right: auto;
}

/* Buttons */

.cta-button {
    display: inline-block;
    background: linear-gradient(135deg, #0f766e 0%, #1e40af 100%);
    color: white;
    padding: 1rem 2.7rem;
    border-radius: 50px;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 6px 18px rgba(15, 118, 110, 0.45);
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 28px rgba(15, 118, 110, 0.6);
}

/* Features */

.features {
    padding: 4.5rem 2rem;
}

.features h3 {
    text-align: center;
    font-size: 2.1rem;
    color: #0f172a;
    margin-bottom: 3.5rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 2.2rem;
}

.feature-card {
    background: #f8fafc;
    padding: 2.2rem;
    border-radius: 18px;
    text-align: center;
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 18px 40px rgba(0, 0, 0, 0.12);
}

.icon {
    font-size: 3rem;
    margin-bottom: 1.2rem;
}

.feature-card h4 {
    color: #0f172a;
    margin-bottom: 1rem;
    font-size: 1.35rem;
}

.feature-card p {
    color: #475569;
    font-size: 1.05rem;
}

/* About */

.about {
    padding: 4.5rem 2rem;
    background: #f1f5f9;
}

.about h3 {
    font-size: 2.1rem;
    color: #0f172a;
    margin-bottom: 1.8rem;
    text-align: center;
}

.about p {
    font-size: 1.15rem;
    color: #334155;
    max-width: 950px;
    margin: 0 auto 1.8rem;
    text-align: center;
}

/* Citation */

.citation {
    background: white;
    padding: 2.3rem;
    border-radius: 18px;
    max-width: 950px;
    margin: 2.5rem auto;
    border-left: 6px solid #0f766e;
}

.citation h4 {
    color: #0f766e;
    margin-bottom: 1.2rem;
    font-size: 1.4rem;
}

.citation p {
    text-align: left;
    margin-bottom: 0.6rem;
    font-size: 1.05rem;
    color: #334155;
}

/* CTA section */

.cta-section {
    padding: 4.5rem 2rem;
    text-align: center;
    background: linear-gradient(135deg, #0f766e 0%, #1e3a8a 100%);
    color: white;
}

.cta-section h3 {
    font-size: 2.2rem;
    margin-bottom: 1.2rem;
}

.cta-section p {
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    opacity: 0.95;
}

.cta-button-large {
    display: inline-block;
    background: white;
    color: #0f766e;
    padding: 1.3rem 3.2rem;
    border-radius: 50px;
    text-decoration: none;
    font-size: 1.25rem;
    font-weight: 600;
    transition: transform 0.3s, box-shadow 0.3s;
    box-shadow: 0 6px 22px rgba(0, 0, 0, 0.25);
}

.cta-button-large:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 32px rgba(0, 0, 0, 0.35);
}

/* Footer */

footer {
    background: #0f172a;
    color: white;
    text-align: center;
    padding: 2.2rem;
}

footer p {
    margin: 0.5rem 0;
    opacity: 0.85;
}

footer a {
    color: #5eead4;
    text-decoration: none;
}

footer a:hover {
    text-decoration: underline;
}

/* Responsive */

@media (max-width: 768px) {
    header h1 {
        font-size: 2.2rem;
    }

    .hero-content h2 {
        font-size: 1.6rem;
    }

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