/* 蓝色主题样式 */
:root {
    --primary-color: #3498db;
    --primary-dark: #2980b9;
    --secondary-color: #f8f9fa;
    --text-color: #333;
    --light-gray: #e9ecef;
    --border-color: #dee2e6;
    --tab-active: #3498db;
    --tab-inactive: #6c757d;
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
    background-color: var(--secondary-color);
    color: var(--text-color);
}

.container {
    max-width: 900px;
    margin: 30px auto;
    padding: 0;
    background-color: white;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
    overflow: hidden;
}

.header {
    background-color: var(--primary-color);
    color: white;
    padding: 25px;
    text-align: center;
}

.header h1 {
    margin: 0;
    font-size: 28px;
    font-weight: 600;
}

.header p {
    margin: 10px 0 0;
    opacity: 0.9;
    font-size: 16px;
}

.tabs {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    padding: 0 25px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 12px 20px;
    margin-right: 5px;
    cursor: pointer;
    font-size: 15px;
    font-weight: 500;
    color: var(--tab-inactive);
    border-bottom: 2px solid transparent;
    transition: all 0.3s;
}

.tab-btn.active {
    color: var(--tab-active);
    border-bottom-color: var(--tab-active);
}

.tab-btn:hover:not(.active) {
    color: var(--primary-dark);
}

.tab-content {
    display: none;
    padding: 25px;
}

.tab-content.active {
    display: block;
}

form {
    padding: 0;
}

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

.form-row {
    display: flex;
    gap: 20px;
}

.form-row .form-group {
    flex: 1;
}

label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--primary-dark);
}

.hint {
    font-size: 13px;
    color: var(--tab-inactive);
    margin: 5px 0 0;
}

textarea, input[type="text"], input[type="file"], select {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 15px;
    transition: border-color 0.3s;
}

textarea:focus, input[type="text"]:focus, select:focus {
    border-color: var(--primary-color);
    outline: none;
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.2);
}

textarea {
    min-height: 250px;
    resize: vertical;
    font-family: 'Consolas', 'Monaco', monospace;
    font-size: 14px;
}

select {
    appearance: none;
    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='%23333' 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;
    background-size: 12px;
}

.btn-encrypt {
    background-color: var(--primary-color);
    color: white;
    border: none;
    padding: 14px 20px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    border-radius: 4px;
    width: 100%;
    transition: background-color 0.3s, transform 0.2s;
}

.btn-encrypt:hover {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-encrypt:active {
    transform: translateY(0);
}

.footer {
    background-color: var(--light-gray);
    padding: 15px;
    text-align: center;
    font-size: 14px;
    color: #6c757d;
}

/* 复选框样式 */
input[type="checkbox"] {
    margin-right: 8px;
    width: auto;
    vertical-align: middle;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .container {
        margin: 15px;
        border-radius: 0;
    }
    
    .form-row {
        flex-direction: column;
        gap: 0;
    }
    
    .tabs {
        padding: 0 15px;
    }
    
    .tab-btn {
        padding: 10px 15px;
        font-size: 14px;
    }
}