body {
    font-family: Arial, sans-serif;
    margin: 20px;
    background: #f9f9f9;
    color: #333;
}

h1 {
    color: #2196F3;
    font-size: 1.8em;
}

table {
    border-collapse: collapse;
    width: 100%;
    background: white;
    border-radius: 6px;
    box-shadow: 0 0 10px rgba(0,0,0,0.1);
    overflow: hidden;
    margin-top: 20px;
}

th, td {
    padding: 12px 15px;
    border-bottom: 1px solid #ddd;
    text-align: left;
    font-size: 0.95em;
}

th {
    background-color: #2196F3;
    color: white;
    text-transform: uppercase;
    font-size: 0.85em;
    letter-spacing: 0.05em;
}

tr:hover {
    background-color: #f1f7ff;
}

tr.heard {
    background-color: #e0f2f1;
    color: #777;
}

tr.heard td {
    text-decoration: line-through;
}

/* Button styles */
.inline-form {
    display: inline-block;
    margin-right: 5px;
}

.btn {
    padding: 6px 10px;
    margin: 2px 0;
    font-size: 0.8em;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    text-align: center;
    transition: background-color 0.3s ease;
    white-space: nowrap;
}

.btn.mark {
    background-color: #4CAF50;
    color: white;
}

.btn.mark:hover {
    background-color: #45a049;
}

.btn.delete {
    background-color: #f44336;
    color: white;
}

.btn.delete:hover {
    background-color: #e53935;
}

.no-data {
    margin-top: 30px;
    font-size: 1.1em;
    color: #666;
}

a {
    display: inline-block;
    margin-top: 20px;
    color: #2196F3;
    text-decoration: none;
    font-weight: 500;
}

a:hover {
    text-decoration: underline;
}

/* Responsive Table */
@media (max-width: 768px) {
    table, thead, tbody, th, td, tr {
        display: block;
        width: 100%;
    }

    thead {
        display: none;
    }

    tr {
        margin-bottom: 15px;
        background: #fff;
        border-radius: 6px;
        box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        padding: 10px;
        overflow: hidden;
    }

    td {
        padding: 35px 15px 10px 15px;
        text-align: left;
        position: relative;
        min-height: 48px;
        box-sizing: border-box;
        word-wrap: break-word;
    }

    td::before {
        content: attr(data-label);
        position: absolute;
        top: 10px;
        left: 15px;
        font-weight: bold;
        color: #2196F3;
        font-size: 0.75em;
        text-transform: uppercase;
        white-space: nowrap;
    }

    .inline-form {
        display: block;
        width: 100%;
        margin: 6px 0;
    }

    .btn {
        width: 100%;
        padding: 10px;
        font-size: 0.9em;
        box-sizing: border-box;
    }
}