* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    padding: 15px;
}

.container {
    width: 60%;
    background-color: #f0f0f0;
    padding: 30px;
    border-radius: 15px;
    transition: all 0.4s ease;
}

header {
    text-align: center;
    margin-bottom: 20px;
}

h1 {
    font-size: 2.2rem;
    margin-bottom: 10px;
    position: relative;
    padding-bottom: 10px;
}

h1::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 80px;
    height: 3px;
    border-radius: 2px;
}

.subtitle {
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
}

.content {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
}

.main-content {
    flex: 3;
}

.sidebar {
    flex: 1;
    padding: 15px;
    border-radius: 8px;
}

p {
    margin-bottom: 15px;
    font-size: 1rem;
    text-align: justify;
}

ul {
    padding-left: 18px;
    margin: 15px 0;
}

ul li {
    line-height: 1.8;
    margin-bottom: 8px;
    position: relative;
    padding-left: 0;
}

a {
    color: #20a53a;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border-bottom: 2px solid transparent;
}

.device-info {
    padding: 12px;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    margin-top: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.device-info i {
    font-size: 1.3rem;
}

.features {
    display: flex;
    gap: 15px;
    margin-top: 20px;
}

.feature-card {
    padding: 20px;
    border-radius: 8px;
    text-align: center;
    flex: 1;
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-3px);
}

.feature-card i {
    font-size: 2.2rem;
    margin-bottom: 12px;
}

@media (max-width: 1024px) {
    .container {
        width: 90%;
        padding: 25px;
    }

    h1 {
        font-size: 1.9rem;
    }

    .content {
        flex-direction: column;
        gap: 15px;
    }

    .features {
        flex-wrap: wrap;
    }

    .feature-card {
        flex: 1 1 45%;
        padding: 18px;
    }
}

@media (max-width: 768px) {
    body {
        padding: 8px;
    }

    .container {
        padding: 20px 15px;
    }

    h1 {
        font-size: 1.7rem;
        padding-bottom: 8px;
    }

    .subtitle {
        font-size: 0.95rem;
    }

    ul li {
        line-height: 1.6;
    }

    .features {
        flex-direction: column;
        gap: 12px;
    }

    .device-info {
        padding: 10px;
        font-size: 0.9rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 18px 12px;
    }

    h1 {
        font-size: 1.5rem;
    }

    ul li {
        font-size: 0.92rem;
    }
    
    .feature-card {
        padding: 15px;
    }
}