body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    line-height: 1.2;
    padding: 10px;
    max-width: 1080px;
    margin: 0 auto;
    color: #333;
    position: relative;
}

.shortcut {
    background: #f5f5f5;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: monospace;
}

h1, h2 {
    color: #2c3e50;
}

.section {
    margin-bottom: 30px;
}

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

li {
    margin: 10px 0;
}

.tip {
    background: #e1f5fe;
    padding: 10px;
    border-radius: 4px;
    margin: 10px 0;
}

.email {
    color: blue;
}

.features {
    margin: 20px 0 40px 0;
    padding: 20px;
    background: #f8f9fa;
    border-radius: 8px;
}

.feature-group {
    margin-bottom: 20px;
}

.feature-group h3 {
    color: #1a73e8;
    margin-bottom: 10px;
}

.back-home {
    display: inline-block;
    color: #1a73e8;
    text-decoration: none;
    padding: 8px 16px;
    border: 1px solid #1a73e8;
    border-radius: 20px;
    margin: 20px 0;
    transition: all 0.3s ease;
}

.back-home:hover {
    background: #1a73e8;
    color: white;
}

.language-selector {
    position: absolute;
    top: 20px;
    right: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
    visibility: hidden;/* hiddden language selector */
}

.language-selector select {
    padding: 8px 12px;
    padding-right: 30px;
    border: 1px solid #1a73e8;
    border-radius: 20px;
    background-color: white;
    color: #1a73e8;
    font-size: 14px;
    cursor: pointer;
    outline: none;
    transition: all 0.3s ease;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%231a73e8' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    -webkit-appearance: none;
    -moz-appearance: none;
    appearance: none;
}

.language-selector select:hover {
    background-color: #f0f7ff;
}

.language-selector select:focus {
    box-shadow: 0 0 0 2px rgba(26, 115, 232, 0.2);
}

.language-selector select::-ms-expand {
    display: none;
}