* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: #f5f5f5;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

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

.nav {
    display: flex;
    gap: 20px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 1px solid #ddd;
}
.nav a {
    text-decoration: none;
    color: #007bff;
    font-weight: 500;
}

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

.messages {
    background: white;
    border-radius: 8px;
    padding: 20px;
    height: 400px;
    overflow-y: auto;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.message {
    margin-bottom: 15px;
    padding-bottom: 15px;
    border-bottom: 1px solid #eee;
}

.message:last-child {
    border-bottom: none;
}

.message-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 5px;
}

.message-header strong {
    color: #007bff;
}

.time {
    color: #999;
    font-size: 0.9em;
}

.message p {
    margin: 5px 0;
}

.message-image {
    max-width: 300px;
    max-height: 300px;
    margin-top: 10px;
    border-radius: 4px;
    cursor: pointer;
    display: block;
}

.message-image:hover {
    opacity: 0.9;
}

#imagePreview {
    margin-top: 10px;
}

#imagePreview img {
    border: 1px solid #ddd;
    border-radius: 4px;
    padding: 5px;
}

#imagePreview button {
    margin-left: 10px;
    background: #dc3545;
    font-size: 12px;
    padding: 5px 10px;
}

.input-area {
    background: white;
    border-radius: 8px;
    padding: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.input-area textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    resize: vertical;
    font-family: inherit;
}

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

button {
    padding: 10px 20px;
    background: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
}

button:hover {
    background: #0056b3;
}

/* 登录页面样式 */
.login-form {
    background: white;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    max-width: 400px;
    margin: 0 auto;
}

.login-form input {
    width: 100%;
    padding: 10px;
    margin-bottom: 15px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.login-form button {
    width: 100%;
}

.error {
    color: #dc3545;
    margin-top: 10px;
    text-align: center;
}

.hint {
    text-align: center;
    margin-top: 20px;
    color: #666;
}

/* 历史记录页面 */
.filter-form {
    background: white;
    padding: 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.filter-form input, .filter-form select {
    margin-right: 10px;
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 4px;
}