/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

/* 容器 */
.container {
    max-width: 580px;
    margin: 0 auto;
    background: #fff;
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

/* 头部 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    padding: 25px;
    text-align: center;
}

header h1 {
    font-size: 26px;
    margin-bottom: 6px;
}

.subtitle {
    opacity: 0.9;
    font-size: 14px;
}

/* 主体 */
main {
    padding: 25px;
}

/* 输入区域 */
.input-section {
    margin-bottom: 15px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #444;
    font-size: 14px;
}

.input-wrapper {
    display: flex;
    gap: 8px;
}

input[type="text"] {
    flex: 1;
    padding: 14px 16px;
    font-size: 16px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    transition: all 0.3s ease;
    outline: none;
}

input[type="text"]:focus {
    border-color: #667eea;
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

input[type="text"]::placeholder {
    color: #aaa;
}

/* 箭头按钮区域 */
.arrow-section {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin: 18px 0;
}

.arrow-btn {
    width: 50px;
    height: 50px;
    font-size: 22px;
    font-weight: bold;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.arrow-btn:first-child {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
}

.arrow-btn:first-child:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(102, 126, 234, 0.4);
}

.arrow-btn:last-child {
    background: linear-gradient(135deg, #28a745 0%, #20c997 100%);
    color: #fff;
}

.arrow-btn:last-child:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 20px rgba(40, 167, 69, 0.4);
}

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

/* 复制按钮 */
.copy-btn {
    padding: 14px 16px;
    background: #f0f0f0;
    color: #666;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.copy-btn:hover {
    background: #e0e0e0;
}

.copy-btn.copied {
    background: #28a745;
    color: #fff;
}

/* 消息提示 */
.message {
    min-height: 20px;
    padding: 6px;
    text-align: center;
    font-size: 14px;
    border-radius: 6px;
    margin-bottom: 12px;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.message.show {
    opacity: 1;
}

.message.success {
    background: #d4edda;
    color: #155724;
}

.message.error {
    background: #f8d7da;
    color: #721c24;
}

/* 信息区域 */
.info-section {
    background: #f8f9fa;
    padding: 18px;
    border-radius: 10px;
    margin-top: 20px;
}

.info-section h3 {
    font-size: 15px;
    margin-bottom: 10px;
    color: #333;
}

.info-section h4 {
    font-size: 14px;
    margin: 12px 0 6px;
    color: #555;
}

.info-section p {
    font-size: 13px;
    color: #666;
    line-height: 1.6;
    margin-bottom: 4px;
}

.info-section ul {
    list-style: none;
    padding-left: 0;
}

.info-section li {
    padding: 5px 0;
    font-size: 13px;
}

.info-section code {
    background: #e9ecef;
    padding: 2px 6px;
    border-radius: 4px;
    font-family: "SFMono-Regular", Consolas, "Liberation Mono", Menlo, monospace;
    font-size: 12px;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 12px;
    background: #f8f9fa;
    color: #888;
    font-size: 12px;
}

/* 响应式 */
@media (max-width: 480px) {
    body {
        padding: 10px;
    }

    header {
        padding: 18px;
    }

    header h1 {
        font-size: 22px;
    }

    main {
        padding: 18px;
    }

    input[type="text"] {
        font-size: 14px;
        padding: 12px 14px;
    }

    .arrow-btn {
        width: 45px;
        height: 45px;
        font-size: 20px;
    }
}