:root {
    --primary-color: #4a90e2;
    --secondary-color: #2c3e50;
    --background-color: #f5f6fa;
    --text-color: #2c3e50;
    --card-background: #ffffff;
    --accent-color: #e74c3c;
}

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

body {
    font-family: 'Roboto', sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
}

header {
    background-color: var(--card-background);
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
}

nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    display: flex;
    align-items: center;
}

.logo-img {
    height: 40px;
    margin-right: 10px;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    margin-left: 2rem;
    transition: color 0.3s ease;
}

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

main {
    margin-top: 4rem;
}

section {
    padding: 4rem 2rem;
    max-width: 1200px;
    margin: 0 auto;
}

.hero {
    text-align: center;
    padding: 6rem 2rem;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    margin-top: 0;
}

.hero h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.feature-card {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-description {
    margin-top: 2rem;
    padding: 1.5rem;
    background-color: rgba(74, 144, 226, 0.1);
    border-radius: 8px;
    font-style: italic;
}

.how-to-use-container {
    display: flex;
    flex-direction: column;
    gap: 2rem;
    background: var(--card-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.steps {
    order: 2;
}

.steps ol {
    padding-left: 1.5rem;
}

.steps li {
    margin-bottom: 1rem;
}

.screenshots {
    order: 1;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    width: 100%;
}

.screenshot {
    width: 100%;
}

.screenshot img {
    width: 100%;
    border-radius: 4px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.download-container {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    max-width: 600px;
    margin: 0 auto;
}

.signup-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

input[type="email"] {
    padding: 0.8rem;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 1rem;
}

button {
    background-color: var(--primary-color);
    color: white;
    padding: 0.8rem;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 1rem;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #357abd;
}

.donation-container {
    text-align: center;
    background: var(--card-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    max-width: 800px;
    margin: 0 auto;
}

.donation-options {
    margin: 1.5rem 0;
}

.donate-button {
    display: inline-block;
    background-color: var(--primary-color);
    color: white;
    padding: 1rem 2rem;
    text-decoration: none;
    border-radius: 4px;
    margin-top: 1rem;
    transition: background-color 0.3s ease;
}

.donate-button:hover {
    background-color: #357abd;
}

.qr-code-container {
    margin: 2rem 0;
    padding: 1.5rem;
    background-color: rgba(74, 144, 226, 0.05);
    border-radius: 8px;
    border: 1px solid rgba(74, 144, 226, 0.2);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.qr-code-container h3 {
    margin-bottom: 1.5rem;
    color: var(--secondary-color);
    text-align: center;
}

.qr-code {
    max-width: 600px;
    width: 100%;
    margin: 1rem auto;
    display: block;
    border-radius: 4px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.qr-code-container p {
    margin-top: 1rem;
    text-align: center;
    max-width: 500px;
}

.donation-note {
    margin-top: 1rem;
    font-style: italic;
    color: #666;
}

.contact-container {
    background: var(--card-background);
    padding: 2rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-info {
    margin-top: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.contact-info a {
    color: var(--primary-color);
    text-decoration: none;
}

.contact-info a:hover {
    text-decoration: underline;
}

.contact-info i {
    margin-right: 0.5rem;
    color: var(--primary-color);
}

footer {
    background-color: var(--secondary-color);
    color: white;
    padding: 2rem;
    text-align: center;
    margin-top: 4rem;
}

.footer-content a {
    color: white;
    text-decoration: none;
}

h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--secondary-color);
}

@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    section {
        padding: 2rem 1rem;
    }
    
    .how-to-use-container {
        flex-direction: column;
    }
    
    .steps, .screenshots {
        order: 0;
    }
    
    .qr-code {
        max-width: 400px;
    }
    
    .donation-container {
        max-width: 95%;
    }
}