body { 
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    max-width: 800px; 
    margin: 0 auto; 
    padding: 20px;
    background: #f5f5f5;
    color: #333;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.container {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 20px;
    display: flex;
    flex-direction: column;
    height: calc(100vh - 40px);
}

.messages-container {
    flex: 1;
    overflow-y: auto;
    margin-bottom: 20px;
    padding-right: 10px;
    min-height: 0;
}

.message { 
    margin: 10px 0; 
    padding: 15px;
    border: 1px solid #eee;
    border-radius: 8px;
    background: white;
    transition: all 0.2s ease;
}

.message:hover {
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.username { 
    font-weight: 600; 
    color: #2196F3;
    margin-right: 8px;
}

.time { 
    color: #999; 
    font-size: 0.8em;
    float: right;
}

.encrypted { 
    color: #4CAF50;
    font-size: 0.9em;
    margin-left: 8px;
}

.signature { 
    color: #FF9800; 
    font-size: 0.9em;
    margin-top: 5px;
    padding-top: 5px;
    border-top: 1px solid #eee;
}

.form-container {
    background: white;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-top: auto;
}

input[type="text"] { 
    width: 100%;
    padding: 10px;
    margin: 5px 0;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}

textarea { 
    width: 100%; 
    height: 100px; 
    margin: 10px 0;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    resize: vertical;
    box-sizing: border-box;
}

button { 
    background: #2196F3;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 4px;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.2s ease;
}

button:hover {
    background: #1976D2;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-shrink: 0;
}

.header h1 {
    margin: 0;
    color: #2196F3;
}

.header-buttons {
    display: flex;
    gap: 10px;
}

.header-buttons a {
    background: white;
    padding: 8px 16px;
    border-radius: 4px;
    text-decoration: none;
    color: #2196F3;
    font-weight: 600;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: all 0.2s ease;
}

.header-buttons a:hover {
    background: #2196F3;
    color: white;
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
}

.modal-content {
    position: relative;
    background: white;
    margin: 50px auto;
    padding: 20px;
    width: 80%;
    max-width: 600px;
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
}

.close {
    position: absolute;
    right: 20px;
    top: 20px;
    font-size: 24px;
    cursor: pointer;
    color: #666;
}

.api-info { 
    margin: 20px 0; 
    padding: 15px;
    background: #f8f9fa;
    border-radius: 8px;
    border: 1px solid #eee;
}

.api-info pre {
    background: #2d2d2d;
    color: #fff;
    padding: 15px;
    border-radius: 4px;
    overflow-x: auto;
}

.checkbox-wrapper {
    margin: 10px 0;
    display: flex;
    align-items: center;
}

.checkbox-wrapper input[type="checkbox"] {
    margin-right: 8px;
}

.checkbox-wrapper label {
    color: #666;
}

.clear {
    clear: both;
}