/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Roboto', Arial, sans-serif;
}

body {
    background: #f7f8fa;
    color: #222;
    min-height: 100vh;
}

/* Header and navigation */
header {
    background: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 1000px;
    margin: 0 auto;
    padding: 1rem 2rem;
}

.logo {
    font-weight: 700;
    font-size: 1.4rem;
    color: #1e88e5;
    letter-spacing: 1px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

nav ul li a {
    color: #222;
    text-decoration: none;
    font-weight: 500;
    padding: .5rem 1rem;
    border-radius: 6px;
    transition: background .2s;
}

nav ul li a.active,
nav ul li a:hover {
    background: #e3f2fd;
    color: #1e88e5;
}

/* Main content */
main {
    max-width: 900px;
    margin: 2rem auto;
    padding: 1rem;
}

/* Hero section */
.hero {
    background: linear-gradient(90deg, #1e88e5 0%, #6ab7ff 100%);
    color: #fff;
    padding: 2rem;
    border-radius: 14px;
    text-align: center;
    margin-bottom: 2rem;
}

.hero h1 {
    font-size: 2.2rem;
    margin-bottom: 1rem;
}

.hero p {
    font-size: 1.2rem;
    margin-bottom: 1.5rem;
}

.cta {
    display: inline-block;
    background: #fff;
    color: #1e88e5;
    font-weight: bold;
    padding: .75rem 2rem;
    border-radius: 24px;
    text-decoration: none;
    box-shadow: 0 4px 16px rgba(0,0,0,0.06);
    transition: background .2s, color .2s;
}

.cta:hover {
    background: #1e88e5;
    color: #fff;
}

/* Features section */
.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px,1fr));
    gap: 1.5rem;
    margin-top: 2rem;
}

.features div {
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(30,136,229,0.09);
    padding: 1.5rem;
    text-align: center;
    transition: transform .15s;
}

.features div:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 6px 18px rgba(30,136,229,0.12);
}

/* Card styles */
.card-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px,1fr));
    gap: 1.5rem;
}

.card {
    background: #fff;
    border-radius: 10px;
    box-shadow: 0 2px 8px rgba(30,136,229,0.09);
    padding: 1.5rem;
    transition: transform .15s;
}

.card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: 0 6px 18px rgba(30,136,229,0.12);
}

.card h3 {
    color: #1e88e5;
    margin-bottom: .5rem;
}

.card p {
    color: #444;
}

/* Materials list */
.materials-list {
    list-style: none;
    padding: 0;
}

.materials-list li {
    margin-bottom: 1rem;
    background: #fff;
    border-radius: 8px;
    box-shadow: 0 1px 6px rgba(30,136,229,0.07);
    padding: .75rem 1.25rem;
    transition: background .2s;
}

.materials-list li:hover {
    background: #e3f2fd;
}

.materials-list a {
    color: #1e88e5;
    text-decoration: none;
    font-weight: 500;
}

/* Content section */
.content h1 {
    margin-bottom: 1.1rem;
    color: #1e88e5;
    font-weight: bold;
}

.content h2 {
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: #444;
}

footer {
    background: #fff;
    color: #999;
    text-align: center;
    padding: 1rem 0;
    margin-top: 4rem;
    border-top: 1px solid #ececec;
    font-size: 1rem;
}

/* Responsive design */
@media (max-width: 700px) {
    nav {
        flex-direction: column;
        gap: 1rem;
        padding: 1rem;
    }
    main {
        padding: .5rem;
    }
    .hero {
        padding: 1rem;
    }
    .features {
        grid-template-columns: 1fr;
    }
    .card-list {
        grid-template-columns: 1fr;
    }
}