* {
    box-sizing: border-box;
}

body {
    font-family: system-ui, sans-serif;
    margin: 20px;
    background: #f5f5f5;
}

h1 {
    text-align: center;
}

h2 {
    font-size: 20px;
    margin-bottom: 5px;
}

section,
.section {
    margin-bottom: 20px;
}

#status {
    text-align: center;
    margin-bottom: 20px;
    font-size: 18px;
}

ul {
    list-style: none;
    padding: 0;
}

li {
    background: white;
    margin-bottom: 10px;
    padding: 16px;
    border-radius: 10px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

#navbar {
    position: sticky;
    top: 0;
    background: #ffffff;
    padding: 12px 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-radius: 12px;
    margin-bottom: 20px;
    box-shadow: 0 2px 6px rgba(0,0,0,0.1);
    z-index: 1000;
}

.nav-left {
    font-weight: bold;
    font-size: 18px;
}

.nav-right a {
    margin-left: 15px;
    text-decoration: none;
    color: #333;
    font-size: 16px;
}

.nav-right a:hover {
    text-decoration: underline;
}

button {
    border: none;
    padding: 6px 10px;
    border-radius: 6px;
    cursor: pointer;
}

@media (min-width: 600px) {
    body {
        max-width: 500px;
        margin: auto;
    }
}

@keyframes fadeInOut {
    0% { opacity: 0; }
    50% { opacity: 1; }
    100% { opacity: 0; }
}