html, body {
    height: 100%;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    background-color: #f4f4f9;
    color: #333;
}

header {
    background-color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 1rem 2rem;
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.site-title {
    font-size: 1.5em;
    font-weight: bold;
    margin-right: 2em;
}

nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: flex-end;
}

nav ul li {
    margin-left: 20px;
}

nav a {
    text-decoration: none;
    color: #555;
    font-weight: 500;
    transition: color 0.3s ease;
}

nav a:hover {
    color: #007aff;
}

main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 2rem;
}

.welcome h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    animation: fadeInDown 1s ease-out;
}

.welcome p {
    font-size: 1.2rem;
    color: #666;
    margin-bottom: 2rem;
    animation: fadeInUp 1s ease-out;
}

button {
    background-color: #007aff;
    color: white;
    border: none;
    padding: 15px 30px;
    font-size: 1rem;
    border-radius: 8px;
    cursor: pointer;
    transition: background-color 0.3s ease, transform 0.2s ease;
    box-shadow: 0 4px 12px rgba(0, 122, 255, 0.2);
}

button:hover {
    background-color: #0056b3;
    transform: translateY(-2px);
}

button:active {
    transform: translateY(1px);
}

footer {
    margin-top: auto;
    width: 100%;
    text-align: center;
    padding: 1em 0;
    background: #f5f5f5;
    font-size: 0.9rem;
    color: #888;
    box-shadow: 0 -2px 4px rgba(0,0,0,0.05);
}

@keyframes fadeInDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}