:root {
    --primary-color: #4a90e2;
    --bg-color: #f8f9fa;
    --text-color: #333;
    --border-color: #ddd;
    --highlight-bg: rgba(255, 165, 0, 0.4);
    --error-color: #e74c3c;
    --card-bg: #ffffff;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    margin-bottom: 30px;
}

header h1 {
    color: var(--primary-color);
    margin-bottom: 10px;
}

header p {
    color: #666;
}

main {
    display: grid;
    grid-template-columns: 1fr;
    gap: 30px;
}

@media (min-width: 768px) {
    main {
        grid-template-columns: 1.5fr 1fr;
    }
}

.input-section, .output-section {
    background: var(--card-bg);
    padding: 24px;
    border-radius: 12px;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
}

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

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

input[type="text"] {
    width: 100%;
    padding: 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 16px;
    font-family: inherit;
    outline: none;
    transition: border-color 0.2s;
}

input[type="text"]:focus {
    border-color: var(--primary-color);
}

.error-message {
    color: var(--error-color);
    font-size: 14px;
    margin-top: 5px;
    min-height: 20px;
}

/* 极精细的编辑器对齐逻辑 */
.text-editor {
    position: relative;
    width: 100%;
    height: 350px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    background-color: #fff;
}

.text-editor:focus-within {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 1px var(--primary-color);
}

.backdrop, #sourceText {
    position: absolute !important;
    top: 0 !important;
    left: 0 !important;
    width: 100% !important;
    height: 100% !important;
    margin: 0 !important;
    padding: 12px !important;
    
    font-size: 16px !important;
    /* 使用完全等宽的字体栈，确保中英文对齐 */
    font-family: 'Consolas', 'Monaco', 'Menlo', 'Courier New', monospace !important;
    line-height: 24px !important;
    
    white-space: pre-wrap !important;
    word-wrap: break-word !important;
    word-break: break-all !important;
    
    overflow-y: scroll !important; /* 强制显示垂直滚动条，确保可用宽度完全一致 */
    overflow-x: hidden !important;
    box-sizing: border-box !important;
    
    letter-spacing: normal !important;
    text-transform: none !important;
    text-align: left !important;
    tab-size: 4 !important;
}

#sourceText {
    background: transparent !important;
    color: #333 !important;
    z-index: 2;
    resize: none !important;
    outline: none !important;
    border: none !important;
    -webkit-text-fill-color: #333;
}

.backdrop {
    background-color: #fff !important;
    /* 这里的文字颜色必须是透明的，我们只显示 mark 背景 */
    color: transparent !important;
    z-index: 1;
    pointer-events: none;
    border: none !important;
}

/* 高亮样式 */
mark {
    background-color: var(--highlight-bg) !important;
    color: transparent !important;
    border-radius: 2px !important;
    padding: 0 !important;
    margin: 0 !important;
    display: inline !important;
}

/* 结果列表样式 */
.result-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 15px;
    flex-wrap: wrap;
}

.result-header h2 {
    font-size: 1.2rem;
    flex-grow: 1;
}

.btn-group {
    display: flex;
    gap: 8px;
}

.secondary-btn {
    padding: 6px 12px;
    border: 1px solid var(--primary-color);
    background: transparent;
    color: var(--primary-color);
    border-radius: 4px;
    cursor: pointer;
    font-size: 14px;
    transition: all 0.2s;
}

.secondary-btn:hover {
    background: var(--primary-color);
    color: white;
}

.result-list {
    height: 420px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    padding: 10px;
    background: #fafafa;
}

.match-item {
    padding: 8px 12px;
    background: white;
    border-bottom: 1px solid #eee;
    font-family: 'Courier New', Courier, monospace;
    font-size: 14px;
    word-break: break-all;
}

.match-item:last-child {
    border-bottom: none;
}

.empty-tip {
    color: #999;
    text-align: center;
    margin-top: 50px;
}

footer {
    text-align: center;
    margin-top: 40px;
    color: #888;
    font-size: 0.9rem;
}