:root{
    --black:#12100E;
    --brown:#915224;
    --paper:#F5F0E1;
    --cyan:#294341;
    --gray:#777;
    --light-brown:#b88650;
}
*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}
body{
    background-color:var(--paper);
    color:var(--black);
    font-family:"SimSun","思源宋体",serif;
    line-height:1.7;
}
/* 首页专属八卦背景样式 */
body.index-bg{
    background-color:#0c0a08;
    background-image:url("");
    position:relative;
}
body.index-bg::before{
    content:"☯";
    position:fixed;
    z-index:0;
    font-size:320px;
    color:rgba(145, 82, 36,0.08);
    top:50%;
    left:50%;
    transform:translate(-50%,-50%);
}
.wrap{
    max-width:720px;
    margin:0 auto;
    padding:16px;
    position:relative;
    z-index:1;
}
.header{
    text-align:center;
    margin:30px 0;
}
.header h1{
    color:var(--brown);
    font-size:28px;
}
.subtitle{
    color:var(--gray);
    margin-top:6px;
}

.grid-card{
    display:grid;
    grid-template-columns:1fr 1fr;
    gap:16px;
}
.card{
    background:#fff;
    border:1px solid #ddd;
    border-radius:10px;
    padding:24px 12px;
    text-align:center;
    text-decoration:none;
    color:var(--black);
    transition:0.2s ease;
}
.card:active{
    background:#f9f4e8;
    border-color:var(--brown);
}
.card-icon{
    font-size:36px;
    margin-bottom:10px;
    color:var(--brown);
}
.card-title{
    font-size:16px;
}

.modal{
    position:fixed;
    inset:0;
    background:rgba(0,0,0,0.8);
    display:flex;
    align-items:center;
    justify-content:center;
    z-index:999;
}
.modal-box{
    width:90%;
    max-width:520px;
    background:var(--paper);
    padding:24px;
    border-radius:12px;
}
.modal-box h3{
    margin-bottom:12px;
    color:var(--brown);
}
.check-item{
    display:block;
    margin:16px 0;
}
.btn-primary{
    width:100%;
    padding:13px;
    background:var(--brown);
    color:#fff;
    border:none;
    border-radius:8px;
    font-size:16px;
}
.btn-primary:disabled{
    opacity:0.5;
    cursor:not-allowed;
}
.btn-primary:active{
    background:var(--light-brown);
}

.footer{
    margin-top:40px;
    text-align:center;
    color:var(--gray);
    font-size:13px;
}

.form-item{
    margin:18px 0;
}
.form-item label{
    display:block;
    margin-bottom:6px;
    font-weight:bold;
}
input,select{
    width:100%;
    padding:12px;
    border:1px solid #ccc;
    border-radius:6px;
    font-size:16px;
}
.back-btn{
    display:inline-block;
    margin:10px 0;
    color:var(--brown);
    font-size:15px;
    text-decoration:none;
}
.catalog-title{
    margin:28px 0 10px;
    color:#915224;
    font-weight:bold;
    font-size:18px;
}

/* === 新增：运算结果面板样式（全部推演页面共用） === */
.result-panel{
    margin-top:32px;
    background:#fff;
    border:1px solid #d8c8b8;
    border-radius:12px;
    padding:22px;
}
.result-panel h3{
    color:var(--brown);
    border-bottom:1px solid #ddd;
    padding-bottom:10px;
    margin-bottom:16px;
}
.result-line{
    font-size:17px;
    margin:10px 0;
    line-height:1.8;
}
.result-tip{
    margin-top:20px;
    font-size:14px;
    color:#666;
    padding-top:12px;
    border-top:1px dashed #ddd;
}