:root {
    --primary: #8BC34A;
    --primary-dark: #689F38;
    --primary-light: #DCEDC8;
    --accent: #E8C547;
    --accent-dark: #D4A017;
    --text: #212121;
    --text-light: #757575;
    --bg: #FFFFFF;
    --bg-light: #F8F9FA;
    --bg-dark: #ECEFF1;
    --border: #E0E0E0;
}

*{margin:0;padding:0;box-sizing:border-box;font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Helvetica Neue',Arial,sans-serif}
body{color:var(--text);background:var(--bg);line-height:1.6}
a{text-decoration:none;color:var(--primary-dark);transition:color 0.3s}
a:hover{color:var(--accent-dark)}
.container{max-width:1200px;margin:0 auto;padding:0 20px}

/* Header */
header{position:fixed;top:0;left:0;width:100%;z-index:1000;background:rgba(255,255,255,0.95);backdrop-filter:blur(10px);border-bottom:1px solid var(--border);transition:all 0.3s}
.header-inner{display:flex;justify-content:space-between;align-items:center;height:70px}
.logo{display:flex;align-items:center;font-size:24px;font-weight:800;color:var(--primary-dark);letter-spacing:-0.5px}
.logo span{color:var(--accent-dark)}
nav ul{display:flex;list-style:none;gap:30px;align-items:center}
nav a{color:var(--text);font-weight:500;font-size:15px}
nav a:hover{color:var(--primary-dark)}
.lang-switch{display:flex;gap:8px;align-items:center}
.lang-switch a{font-size:13px;padding:4px 10px;border-radius:4px;color:var(--text-light)}
.lang-switch a.active{background:var(--primary);color:#fff}
.mobile-toggle{display:none;font-size:24px;cursor:pointer}
.btn{display:inline-block;padding:10px 24px;border-radius:6px;font-weight:600;font-size:14px;cursor:pointer;border:none;transition:all 0.3s}
.btn-primary{background:var(--primary);color:#fff}
.btn-primary:hover{background:var(--primary-dark);color:#fff}
.btn-outline{border:2px solid var(--primary);color:var(--primary-dark);background:transparent}
.btn-outline:hover{background:var(--primary);color:#fff}
.btn-accent{background:var(--accent);color:var(--text)}
.btn-accent:hover{background:var(--accent-dark)}

/* Hero */
.hero{min-height:100vh;display:flex;align-items:center;background:linear-gradient(135deg,#f1f8e9 0%,#fff8e1 100%);position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-50%;right:-20%;width:600px;height:600px;background:rgba(139,195,74,0.1);border-radius:50%}
.hero::after{content:'';position:absolute;bottom:-30%;left:-10%;width:400px;height:400px;background:rgba(232,197,71,0.1);border-radius:50%}
.hero-content{position:relative;z-index:2;max-width:700px}
.hero h1{font-size:52px;font-weight:800;line-height:1.2;margin-bottom:20px;color:var(--text)}
.hero h1 span{color:var(--primary-dark)}
.hero p{font-size:20px;color:var(--text-light);margin-bottom:40px}
.hero-buttons{display:flex;gap:16px}
.hero-brand{display:flex;align-items:center;justify-content:center;gap:24px;margin-bottom:36px;flex-wrap:wrap}
.hero-brand-logo{width:120px;height:auto;border-radius:12px;box-shadow:0 4px 16px rgba(0,0,0,0.08)}
.hero-brand-text{text-align:left;display:flex;flex-direction:column;justify-content:center}
.hero-brand-text .zh{font-size:40px;font-weight:800;color:var(--primary-dark);letter-spacing:4px;margin-bottom:4px}
.hero-brand-text .en{font-size:28px;font-weight:500;color:var(--text-light);letter-spacing:2px}

/* Sections */
.section{padding:100px 0}
.section-title{text-align:center;margin-bottom:60px}
.section-title h2{font-size:36px;font-weight:700;margin-bottom:16px}
.section-title p{font-size:18px;color:var(--text-light);max-width:600px;margin:0 auto}

/* Cards */
.card-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:30px}
.card{background:var(--bg);border-radius:16px;padding:40px 30px;box-shadow:0 4px 20px rgba(0,0,0,0.06);transition:all 0.3s;border:1px solid var(--border)}
.card:hover{transform:translateY(-5px);box-shadow:0 12px 30px rgba(0,0,0,0.1)}
.card-icon{width:60px;height:60px;border-radius:12px;display:flex;align-items:center;justify-content:center;font-size:28px;margin-bottom:24px}
.card-icon.ai{background:#E3F2FD;color:#1976D2}
.card-icon.quantum{background:#F3E5F5;color:#7B1FA2}
.card-icon.space{background:#E8F5E9;color:#388E3C}
.card-icon.biomed{background:#FFF3E0;color:#F57C00}
.card h3{font-size:20px;margin-bottom:12px}
.card p{color:var(--text-light);font-size:15px;line-height:1.7}

/* Stats */
.stats{background:linear-gradient(135deg,var(--primary-dark) 0%,var(--primary) 100%);color:#fff;padding:80px 0}
.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:30px;text-align:center}
.stat-number{font-size:48px;font-weight:800;margin-bottom:8px}
.stat-label{font-size:16px;opacity:0.9}

/* About */
.about-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center}
.about-content h2{font-size:36px;margin-bottom:24px}
.about-content p{color:var(--text-light);margin-bottom:20px;font-size:16px;line-height:1.8}
.about-image{background:var(--bg-light);border-radius:20px;height:400px;display:flex;align-items:center;justify-content:center;overflow:hidden}
.about-image img{width:100%;height:100%;object-fit:cover;border-radius:20px}

/* Contact */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:60px}
.contact-info h3{font-size:28px;margin-bottom:24px}
.contact-item{display:flex;gap:16px;margin-bottom:24px;align-items:flex-start}
.contact-item i{width:40px;height:40px;background:var(--primary-light);border-radius:10px;display:flex;align-items:center;justify-content:center;color:var(--primary-dark);font-size:18px;flex-shrink:0}
.contact-item h4{font-size:16px;margin-bottom:4px}
.contact-item p{color:var(--text-light);font-size:14px}
.contact-form{background:var(--bg-light);padding:40px;border-radius:16px}
.form-group{margin-bottom:20px}
.form-group label{display:block;margin-bottom:8px;font-weight:500;font-size:14px}
.form-group input,.form-group textarea,.form-group select{width:100%;padding:12px 16px;border:1px solid var(--border);border-radius:8px;font-size:15px;transition:border 0.3s}
.form-group input:focus,.form-group textarea:focus,.form-group select:focus{outline:none;border-color:var(--primary)}
.form-group textarea{min-height:120px;resize:vertical}

/* Footer */
footer{background:var(--text);color:#fff;padding:60px 0 30px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
.footer-brand h3{font-size:24px;margin-bottom:16px;color:var(--primary)}
.footer-brand p{color:rgba(255,255,255,0.7);font-size:14px;line-height:1.8}
.footer-col h4{font-size:16px;margin-bottom:20px;color:#fff}
.footer-col ul{list-style:none}
.footer-col li{margin-bottom:12px}
.footer-col a{color:rgba(255,255,255,0.7);font-size:14px}
.footer-col a:hover{color:var(--primary)}
.footer-bottom{border-top:1px solid rgba(255,255,255,0.1);padding-top:20px;display:flex;justify-content:space-between;align-items:center}
.footer-bottom p{color:rgba(255,255,255,0.5);font-size:13px}

/* Auth */
.auth-page{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#f1f8e9 0%,#fff8e1 100%);padding:40px 20px}
.auth-box{background:#fff;padding:48px;border-radius:20px;box-shadow:0 10px 40px rgba(0,0,0,0.08);width:100%;max-width:440px}
.auth-box h2{font-size:28px;margin-bottom:8px;text-align:center}
.auth-box p{color:var(--text-light);text-align:center;margin-bottom:32px;font-size:14px}
.auth-footer{text-align:center;margin-top:24px;color:var(--text-light);font-size:14px}
.auth-footer a{color:var(--primary-dark);font-weight:600}
.role-select{display:flex;gap:12px;margin-bottom:20px}
.role-option{flex:1;padding:16px;border:2px solid var(--border);border-radius:12px;text-align:center;cursor:pointer;transition:all 0.3s}
.role-option:hover{border-color:var(--primary)}
.role-option.selected{border-color:var(--primary);background:var(--primary-light)}
.role-option h4{font-size:15px;margin-bottom:4px}
.role-option p{font-size:12px;color:var(--text-light)}

/* Admin */
.admin-layout{display:grid;grid-template-columns:260px 1fr;min-height:100vh}
.admin-sidebar{background:var(--text);color:#fff;padding:24px}
.admin-sidebar .logo{color:#fff;margin-bottom:40px}
.admin-nav{list-style:none}
.admin-nav li{margin-bottom:4px}
.admin-nav a{display:flex;align-items:center;gap:12px;padding:12px 16px;border-radius:8px;color:rgba(255,255,255,0.8);font-size:14px}
.admin-nav a:hover,.admin-nav a.active{background:rgba(255,255,255,0.1);color:#fff}
.admin-main{padding:32px;background:var(--bg-light)}
.admin-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:32px}
.admin-header h1{font-size:24px}
.stats-row{display:grid;grid-template-columns:repeat(4,1fr);gap:20px;margin-bottom:32px}
.stat-card{background:#fff;padding:24px;border-radius:12px;box-shadow:0 2px 8px rgba(0,0,0,0.04)}
.stat-card h3{font-size:14px;color:var(--text-light);margin-bottom:8px;font-weight:500}
.stat-card .number{font-size:28px;font-weight:700;color:var(--text)}
.table-container{background:#fff;border-radius:12px;overflow:hidden;box-shadow:0 2px 8px rgba(0,0,0,0.04)}
table{width:100%;border-collapse:collapse}
th{text-align:left;padding:16px;background:var(--bg-light);font-size:13px;font-weight:600;color:var(--text-light);text-transform:uppercase;letter-spacing:0.5px}
td{padding:16px;border-bottom:1px solid var(--border);font-size:14px}
tr:hover td{background:var(--bg-light)}
.badge{display:inline-block;padding:4px 12px;border-radius:20px;font-size:12px;font-weight:500}
.badge-success{background:#E8F5E9;color:#2E7D32}
.badge-warning{background:#FFF3E0;color:#EF6C00}
.badge-danger{background:#FFEBEE;color:#C62828}

/* Flash */
.flash{padding:16px 20px;border-radius:8px;margin-bottom:20px;font-size:14px}
.flash-success{background:#E8F5E9;color:#2E7D32;border:1px solid #C8E6C9}
.flash-error{background:#FFEBEE;color:#C62828;border:1px solid #FFCDD2}

/* Responsive */
@media(max-width:768px){
    nav ul{display:none;position:absolute;top:70px;left:0;width:100%;background:#fff;flex-direction:column;padding:20px;box-shadow:0 4px 20px rgba(0,0,0,0.1)}
    nav ul.active{display:flex}
    .mobile-toggle{display:block}
    .hero h1{font-size:36px}
    .stats-grid{grid-template-columns:repeat(2,1fr)}
    .about-grid,.contact-grid{grid-template-columns:1fr;gap:40px}
    .footer-grid{grid-template-columns:1fr}
    .admin-layout{grid-template-columns:1fr}
    .admin-sidebar{display:none}
    .stats-row{grid-template-columns:repeat(2,1fr)}
}