@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600&display=swap');

* {
    box-sizing: border-box;
}

body {
    font-family: 'Inter', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 40px 20px;
    margin: 0;
}

#app-container {
    width: 90%;
    max-width: 600px;
    margin: 0 auto;
    background: white;
    padding: 32px;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
}

#main-title {
    font-size: 28px;
    font-weight: 600;
    color: #1a1a2e;
    margin: 0 0 24px;
    padding: 8px 12px;
    border-radius: 8px;
    display: inline-block;
    transition: background-color 0.3s ease;
    letter-spacing: -0.5px;
}

#app-container h2 {
    font-size: 16px;
    font-weight: 600;
    color: #6b7280;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin: 28px 0 12px;
}

#control-panel {
    display: flex;
    gap: 10px;
    margin-bottom: 4px;
    flex-wrap: wrap;
}

#control-panel a {
    padding: 10px 20px;
    cursor: pointer;
    border-radius: 8px;
    text-decoration: none;
    display: inline-block;
    font-size: 14px;
    font-weight: 500;
    background: #667eea;
    color: white;
    transition: background 0.2s, transform 0.1s;
}

#control-panel a:hover {
    background: #5a6fd6;
    transform: translateY(-1px);
}

#control-panel button {
    padding: 10px 20px;
    cursor: pointer;
    border: 2px solid #667eea;
    border-radius: 8px;
    display: inline-block;
    font-size: 14px;
    font-weight: 500;
    background: white;
    color: #667eea;
    font-family: 'Inter', Arial, sans-serif;
    transition: background 0.2s, color 0.2s, transform 0.1s;
}

#control-panel button:hover {
    background: #667eea;
    color: white;
    transform: translateY(-1px);
}

#status-output {
    border: none;
    padding: 16px 20px;
    margin-top: 16px;
    background: linear-gradient(135deg, #e0f7fa, #e8f4fd);
    border-radius: 12px;
    border-left: 4px solid #667eea;
}

#status-output p {
    font-weight: 600;
    color: #374151;
    margin: 0 0 4px;
}

#status-output span {
    display: block;
    font-size: 13px;
    color: #6b7280;
    margin-top: 4px;
}

#item-list {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

#item-list li {
    padding: 10px 16px;
    background: #f8f9ff;
    border-radius: 8px;
    border-left: 3px solid #667eea;
    font-size: 14px;
    font-weight: 500;
    transition: background 0.2s;
}

#item-list li:hover {
    background: #eef0ff;
}

/* --- Task 2 Requirement: The Hiding Class --- */
/* This class must be defined to enable the toggle functionality later. */
.hidden {
    /* Sets the element to be completely invisible and not take up space. */
    display: none;
}