/* 基本样式 */
body { font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; background-color: #f4f7f9; color: #333; line-height: 1.6; margin: 0; padding: 20px; }
.container { max-width: 800px; margin: 0 auto; background: #fff; padding: 30px; border-radius: 12px; box-shadow: 0 4px 20px rgba(0,0,0,0.08); }
header { text-align: center; border-bottom: 1px solid #e0e0e0; padding-bottom: 20px; margin-bottom: 30px; }
header h1 { color: #2c3e50; margin: 0; }
header p { color: #7f8c8d; }

/* 屏幕切换 */
.screen { text-align: center; }
.hidden { display: none; }

/* 按钮样式 */
.btn { cursor: pointer; border: none; padding: 12px 24px; border-radius: 8px; font-size: 16px; font-weight: 500; transition: all 0.2s ease; }
.btn-primary { background-color: #3498db; color: white; }
.btn-primary:hover { background-color: #2980b9; }
.btn-secondary { background-color: #ecf0f1; color: #34495e; }
.btn-secondary:hover { background-color: #bdc3c7; }
.btn-record { background-color: #e74c3c; color: white; display: inline-flex; align-items: center; gap: 8px; }
.btn-record.recording { background-color: #2ecc71; }
.icon-record { width: 12px; height: 12px; background-color: white; border-radius: 50%; }
.btn-record.recording .icon-record { border-radius: 2px; }

/* 练习界面 */
.topic-card { background: #ecf0f1; padding: 20px; border-radius: 8px; margin-bottom: 20px; }
.topic-card h3 { margin: 0 0 10px; color: #34495e; }
.topic-card p { font-size: 18px; color: #2c3e50; }
.timer { font-size: 2.5em; color: #34495e; margin-bottom: 20px; font-family: monospace; }

/* 加载动画 */
.spinner { border: 4px solid #f3f3f3; border-top: 4px solid #3498db; border-radius: 50%; width: 40px; height: 40px; animation: spin 1s linear infinite; margin: 20px auto; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

/* 结果界面 */
.result-section { text-align: left; margin-bottom: 25px; }
.result-section h4 { color: #3498db; border-bottom: 2px solid #ecf0f1; padding-bottom: 5px; }
#strengths-list { list-style: '✅ '; padding-left: 20px; }
.improvement-card { background: #fff9f0; border: 1px solid #fde4b5; border-left: 5px solid #f39c12; padding: 15px; margin-bottom: 15px; border-radius: 5px; }
.improvement-card .dimension { font-weight: bold; color: #d35400; margin-bottom: 5px; }
.improvement-card .original-text { font-style: italic; color: #7f8c8d; border-left: 3px solid #e0e0e0; padding-left: 10px; margin: 10px 0; }
.improvement-card .suggestion { color: #2c3e50; }
.transcript { background: #fafafa; border: 1px solid #eee; padding: 15px; border-radius: 5px; white-space: pre-wrap; word-wrap: break-word; }
.button-group { display: flex; justify-content: center; gap: 20px; margin-top: 30px; }
/* ======== 新增样式开始 ======== */
.performance-metrics {
    display: flex;
    justify-content: space-around;
    background-color: #f8f9fa;
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 25px;
    border: 1px solid #e9ecef;
}

.metric {
    text-align: center;
}

.metric-label {
    display: block;
    font-size: 14px;
    color: #6c757d;
    margin-bottom: 5px;
}

.metric-value {
    font-size: 1.5em;
    font-weight: 500;
    color: #343a40;
    font-family: monospace;
}
/* ======== 新增样式结束 ======== */
/* ======== 新增样式 for 复制按钮 ======== */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px; /* 调整与下方内容的间距 */
}

.section-header h4 {
    margin-bottom: 0; /* 移除h4自带的下边距 */
}

.btn-copy {
    background-color: #f0f0f0;
    color: #555;
    padding: 6px 12px;
    font-size: 14px;
    border: 1px solid #ddd;
}

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

.btn-copy:active {
    background-color: #3498db;
    color: white;
    border-color: #2980b9;
}
/* ======== 新增样式结束 ======== */