:root {
    --primary: #2c52aa;
    --secondary: #1cbe9b;
    --dark: #0F172A;
    --light: #F8FAFC;
    --dark2: #233868;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Inter', sans-serif;
    scroll-behavior: smooth;
}

body {
    background-color: var(--light);
    color: var(--dark);
    line-height: 1.6;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 10%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: 0 4px 6px -1px rgba(0,0,0,0.05);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: padding 0.3s ease, box-shadow 0.3s ease;
}

nav.scrolled {
    padding: 10px 10%;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

nav .logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--dark);
}

nav ul {
    list-style: none;
    display: flex;
    gap: 30px;
    transition: 0.3s ease-in-out;
}

nav a {
    text-decoration: none;
    color: var(--dark);
    font-weight: 600;
    transition: color 0.3s;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.hamburger span {
    width: 25px;
    height: 3px;
    background-color: var(--dark);
    transition: 0.3s;
}

.start {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 20px;
    background: linear-gradient(135deg, rgba(70, 99, 229, 0.1) 0%, rgba(6,182,212,0.1) 100%);
    min-height: 100vh;
}

.start h1 {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: 20px;
    max-width: 800px;
}

.start h1 span {
    background: linear-gradient(to right, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.start p {
    font-size: 1.2rem;
    color: #475569;
    margin-bottom: 40px;
    max-width: 600px;
}

.btn {
    padding: 15px 35px;
    background: var(--dark);
    color: white;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    border-radius: 8px;
    transition: transform 0.3s, box-shadow 0.3s;
}

.btn:hover {
    background: var(--primary);
    transform: translateY(-3px);
    box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
    transition: color 0.3s;
}

.oferta {
    padding: 150px 10%;
    text-align: center;
}

.oferta h2 {
    font-size: 2.5rem;
    margin-bottom: 50px;
}

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
}

.card {
    background: white;
    padding: 40px 30px;
    border-radius: 12px;
    box-shadow: 0 10px 25px -5px rgba(0,0,0,0.05);
    border-top: 4px solid var(--primary);
    transition: transform 0.3s;
}

.card:hover {
    transform: translateY(-10px);
}

.card h3 {
    font-size: 1.5rem;
    margin-bottom: 15px;
    color: var(--dar);
}

.fade-in {
    opacity: 0;
    transform: translateY(40px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}
.fade-in.visible {
    opacity: 1;
    transform: translateY(0);
}

.about  {
    margin-top: 20%;
    text-align: center;
    padding: 150px, 10%;
    margin-left: 10%;
    margin-right: 10%;
}

.about h2 {
    font-size: 2.5rem;
    margin-bottom: 50px;
}

footer {
    margin-top: 7%;
    background: var(--dark);
    color: white;
    text-align: center;
    padding: 60px 20px 40px;
}

footer a { color: var(--secondary); text-decoration: none; font-weight: 600;}
.copyright { font-size: 0.9rem; color: #94A3B8; margin-top: 20px; }

@media (max-width: 768px) {
    .hamburger {
        display: flex;
    }
    nav ul {
        position: absolute;
        top: 100%;
        left: -100%;
        flex-direction: column;
        background: white;
        width: 100%;
        text-align: center;
        padding: 20px 0;
        box-shadow: 0 10px 15px -3px rgba(0,0,0,0.1);
    }
    nav ul.active {
        left: 0;
    }
}