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

body {
    font-family: 'Microsoft YaHei', 'Segoe UI', sans-serif;
    background: linear-gradient(135deg, #f5f7fa, #c3cfe2);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1500px;
    margin: 0 auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.1);
    overflow: hidden;
}

.header {
    background: linear-gradient(135deg, #1a3c6e, #2c5282);
    color: white;
    padding: 25px 40px;
    text-align: center;
    border-bottom: 4px solid #d4a853;
}
.header h1 { font-size: 26px; letter-spacing: 4px; }
.header .subtitle { font-size: 13px; margin-top: 4px; opacity: 0.9; }

/* 概念说明 */
.concept-box {
    background: #fff3cd; border-left: 4px solid #ffc107;
    padding: 12px 16px; border-radius: 0 8px 8px 0;
    font-size: 13px; color: #856404; margin: 15px 20px 0; line-height: 1.8;
}
.concept-box strong { color: #664d03; }

/* 控制区 */
.control-panel {
    display: flex; flex-wrap: wrap; gap: 15px; padding: 12px 25px;
    background: #f8f9fa; border-bottom: 1px solid #e0e0e0; align-items: center;
}
.control-item { display: flex; align-items: center; gap: 6px; }
.control-item label { font-weight: 600; color: #333; font-size: 13px; white-space: nowrap; }
.control-item select {
    padding: 6px 10px; font-size: 13px; border: 2px solid #ccc;
    border-radius: 5px; background: white; cursor: pointer;
}
.control-item select:focus { outline: none; border-color: #1a3c6e; }
.control-item input[type="range"] {
    width: 100px; height: 5px; border-radius: 3px; background: #ddd;
    outline: none; -webkit-appearance: none;
}
.control-item input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; width: 14px; height: 14px; border-radius: 50%;
    background: #d4a853; cursor: pointer;
}

/* 同步控制条 */
.sync-bar {
    display: flex; align-items: center; gap: 15px; padding: 10px 25px;
    background: #f0f4ff; border-bottom: 2px solid #dbeafe;
}
.omega-control {
    flex: 1; display: flex; align-items: center; gap: 10px;
}
.omega-control label {
    font-weight: 600; font-size: 14px; color: #1a3c6e; white-space: nowrap; min-width: 160px;
}
.omega-control input[type="range"] {
    flex: 1; height: 8px; border-radius: 4px; background: #ddd;
    outline: none; -webkit-appearance: none;
}
.omega-control input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none; width: 18px; height: 18px; border-radius: 50%;
    background: #1a3c6e; cursor: pointer; box-shadow: 0 2px 6px rgba(0,0,0,0.3);
}

.btn {
    padding: 8px 16px; border: none; border-radius: 6px; font-size: 13px;
    font-weight: 600; cursor: pointer; transition: all 0.2s; white-space: nowrap;
}
.btn-primary { background: #1a3c6e; color: white; }
.btn-primary:hover { background: #143049; }
.btn-secondary { background: #d4a853; color: #1a3c6e; }
.btn-secondary:hover { background: #c19742; }

/* 三图网格 */
.plots-grid {
    display: flex; gap: 15px; padding: 15px 25px; align-items: flex-start;
}
.nyquist-box { flex: 0 0 480px; }
.bode-stack { flex: 1; display: flex; flex-direction: column; gap: 10px; }

.plot-box {
    background: #f8f9fa; border-radius: 8px; padding: 12px;
    border-left: 4px solid #1a3c6e;
}
.plot-box h3 {
    color: #333; margin-bottom: 8px; font-size: 14px;
    display: flex; align-items: baseline; gap: 6px;
}
.plot-subtitle { font-size: 11px; color: #888; font-weight: normal; }

.plot-box canvas {
    width: 100%; height: auto; background: white;
    border-radius: 5px; box-shadow: 0 2px 6px rgba(0,0,0,0.06);
}

/* 奈奎斯特图坐标范围控制 */
.nyq-controls {
    display: flex; align-items: center; flex-wrap: wrap; gap: 12px;
    margin-bottom: 8px; font-size: 13px;
}
.nyq-auto-label {
    display: inline-flex; align-items: center; gap: 5px;
    font-weight: 600; color: #1a3c6e; cursor: pointer; white-space: nowrap;
}
.nyq-manual {
    display: flex; align-items: center; gap: 14px; flex-wrap: wrap;
    background: #eef2ff; padding: 5px 12px; border-radius: 6px;
    border: 1px solid #dbeafe;
}
.range-field { display: inline-flex; align-items: center; gap: 4px; white-space: nowrap; color: #334155; }
.nyq-manual input[type="number"] {
    width: 64px; padding: 3px 6px; font-size: 13px;
    border: 1px solid #cbd5e1; border-radius: 4px; text-align: center;
}
.nyq-manual input[type="number"]:focus { outline: none; border-color: #1a3c6e; }

/* 对应关系面板 */
.relation-panel {
    display: flex; flex-wrap: wrap; gap: 10px; padding: 12px 25px;
}
.relation-card {
    flex: 1; min-width: 110px; background: #f5f7fa; padding: 10px;
    border-radius: 8px; text-align: center;
}
.relation-card.highlight-card { background: #f0f4ff; border: 1px solid #bfdbfe; }
.relation-card.stability-card { flex: 1.5; min-width: 150px; }
.rel-label { font-size: 11px; color: #666; margin-bottom: 3px; }
.rel-value { font-size: 14px; font-weight: bold; color: #1a3c6e; }
.rel-value.green { color: #16a34a; }
.rel-value.red { color: #dc2626; }

/* 对应关系速查 */
.correspondence-panel {
    margin: 10px 25px 15px; padding: 15px 18px; background: #f8fafc;
    border-radius: 8px; border: 1px solid #e2e8f0;
}
.correspondence-panel h4 {
    font-size: 14px; color: #1a3c6e; margin-bottom: 10px;
    padding-bottom: 6px; border-bottom: 2px solid #d4a853;
}
.corr-grid { display: flex; flex-direction: column; gap: 8px; }
.corr-item {
    display: flex; align-items: center; gap: 10px; font-size: 13px;
    padding: 6px 10px; background: white; border-radius: 6px;
    border: 1px solid #e8e8e8; flex-wrap: wrap;
}
.corr-nyq { color: #1a3c6e; font-weight: 600; min-width: 200px; }
.corr-arrow { color: #d4a853; font-size: 18px; font-weight: bold; }
.corr-bode { color: #d97706; font-weight: 600; min-width: 200px; }
.corr-note { color: #888; font-size: 12px; }

/* 页脚 */
.footer { padding: 18px 40px 22px; text-align: center; }
.footer-divider {
    height: 3px; background: linear-gradient(90deg, transparent, #1a3c6e 20%, #d4a853 50%, #1a3c6e 80%, transparent);
    margin-bottom: 12px;
}
.footer-text { color: #1a3c6e; font-size: 14px; font-weight: 500; letter-spacing: 4px; }

mjx-container { display: inline-block !important; }

@media (max-width: 1100px) {
    .plots-grid { flex-direction: column; }
    .nyquist-box { flex: 1; }
    .control-panel { flex-direction: column; }
    .sync-bar { flex-wrap: wrap; }
}
@media (max-width: 600px) {
    body { padding: 5px; }
    .header { padding: 15px 20px; }
    .header h1 { font-size: 20px; letter-spacing: 2px; }
}