/* main.css - consolidated site styles (based on index.php) */
:root {
    --primary: #4361ee;
    --primary-light: #5e81ff;
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --card-bg: rgba(255, 255, 255, 0.95);
    --text: #333;
    --shadow: 0 10px 30px rgba(0,0,0,0.15);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
    background: var(--bg-gradient) fixed;
    font-size:17px;
    color: var(--text);
    min-height: 100vh;
    padding: 20px 10px;
}
.container { max-width: 1280px; margin: 0 auto; backdrop-filter: blur(10px); }
header { text-align: center; padding: 30px 0; color: white; text-shadow: 0 2px 10px rgba(0,0,0,0.3); }
header h1 { font-size: 2.8rem; margin-bottom: 8px; }
header p { font-size: 1.3rem; opacity: 0.9; }
/* Sub navigation */
.subnav { margin: 12px auto 0; display: flex; width: 100%; max-width: 1000px; justify-content: center; gap: 12px; align-items: center; padding: 6px 8px; flex-wrap: wrap; }
.subnav a { font-size: 1.5em; color: #ffffff; text-decoration: none; padding: 6px 10px; border-radius: 6px; font-weight: 600; display: inline-flex; align-items: center; white-space: nowrap;  }
.subnav a i { margin-right: 8px; }
.subnav a.coming-soon { opacity: 0.6; pointer-events: none; }
.subnav a.active { background: rgba(255,255,255,0.06); }
.card { background: var(--card-bg); border-radius: 20px; box-shadow: var(--shadow); padding: 30px; margin: 25px 0; backdrop-filter: blur(12px); border: 1px solid rgba(255,255,255,0.3); }
/* Converter */
.converter { display: flex; flex-wrap: wrap; gap: 20px; justify-content: center; align-items: end; }
.input-group { position: relative; min-width: 260px; }
.input-group label { display: block; margin-bottom: 8px; font-weight: 600; color: var(--primary); }
.input-group input { width: 100%; padding: 14px 16px; font-size: 1.5rem; border: 2px solid #e0e0e0; border-radius: 12px; transition: all 0.3s; text-align: center; }
.input-group input:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px rgba(67, 97, 238, 0.2); }
.input-group .unit { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); font-size: 1.4rem; color: var(--primary); pointer-events: none; }
.swap-btn { background: var(--primary); color: white; border: none; width: 50px; height: 50px; border-radius: 50%; font-size: 1.5rem; cursor: pointer; transition: 0.3s; box-shadow: 0 4px 15px rgba(67, 97, 238, 0.4); }
.swap-btn:hover { transform: scale(1.1); background: var(--primary-light); }
.table-container { overflow-x: auto; border-radius: 12px; box-shadow: 0 5px 15px rgba(0,0,0,0.1); }
table { width:100%; border-collapse:collapse; background:white }
th { background: linear-gradient(135deg, var(--primary), var(--primary-light)); color:white; padding:5px; font-size:1.1rem}
td { font-size:1.1rem; padding:10px; text-align:center; border-bottom:1px solid #eee }
tr:nth-child(even){ background-color:#f8f9ff }
tr:hover{ background-color:#eef1ff; transition:0.2s }
/* Description / formula */
.formula, .originate, .relat { background: linear-gradient(135deg, #1d00f7 0%, #ff8696 100%); color: white; padding: 15px; border-radius: 16px; margin-top: 30px; }
.formula h3 { margin-bottom: 15px; font-size: 1.5rem; }
.center { text-align: center; font-weight: 600; }
.footer-note, .footer-credits,.footer-links { margin-top:8px; font-size:0.85rem; opacity:0.95 }
.site-footer {
    text-align: center;
    padding: 18px 12px;
    color: rgba(255,255,255,0.92);
    font-size: 0.95rem;
    margin-top: 18px;
}
.site-footer .footer-links a {
    color: inherit;
    text-decoration: underline;
    margin: 0 4px;
}
/* Back to Top Button */
.back-to-top { position: fixed; bottom: 30px; right: 20px; width:38px; height:38px; background-color:#3498db; color:white; border-radius:50%; box-shadow:0 4px 12px rgba(0,0,0,0.25); cursor:pointer; display:flex; justify-content:center; align-items:center; opacity:0; visibility:hidden; transition: opacity 0.3s, visibility 0.3s, transform 0.3s; z-index:1000 }
.back-to-top.show { opacity:1; visibility:visible; transform:translateY(0) }
.back-to-top:hover{ background-color:#2980b9; transform:scale(1.1) }
.relat ul {margin: 20px; line-height: 26px;}
.leftul li{ list-style-type:disc; margin-left:15px; float:left; margin-right:10px; }
.rightul li{ list-style-type:disc; margin-left:15px; float:left; margin-right:10px; }
@media (max-width:600px){ .relat{height:28rem} .leftul li{float:unset;margin-left:0;text-align:center} header h1 { font-size: 2.2rem; } .converter { flex-direction: column; align-items: center; } .input-group { width: 100%; } .subnav { overflow-x:auto; -webkit-overflow-scrolling: touch; gap:8px; padding:8px } .subnav::-webkit-scrollbar{ display:none } }