/* 刊苑 · 科技现代风 */
:root{
  --primary:#4f46e5;
  --primary2:#7c3aed;
  --accent:#06b6d4;
  --bg:#f7f8fc;
  --card:#ffffff;
  --text:#1f2937;
  --muted:#64748b;
  --border:#e5e9f2;
  --radius:14px;
  --shadow:0 2px 12px rgba(79,70,229,.08);
  --shadow-lg:0 8px 30px rgba(79,70,229,.14);
}
*{margin:0;padding:0;box-sizing:border-box}
body{font-family:'Segoe UI','PingFang SC','Microsoft YaHei',sans-serif;background:var(--bg);color:var(--text);font-size:15px;line-height:1.7}
a{text-decoration:none;color:inherit}
h1,h2,h3,h4{line-height:1.3}
input,select,button{font-size:15px;font-family:inherit}

/* 导航 */
.nav{position:sticky;top:0;z-index:100;background:rgba(255,255,255,.9);backdrop-filter:blur(12px);border-bottom:1px solid var(--border)}
.nav-inner{max-width:1180px;margin:0 auto;display:flex;align-items:center;justify-content:space-between;padding:0 24px;height:64px}
.logo{display:flex;align-items:center;gap:8px;font-size:20px;font-weight:800}
.logo-badge{display:inline-flex;width:32px;height:32px;align-items:center;justify-content:center;background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff;border-radius:9px;font-size:16px}
.logo-img{height:34px;width:auto;display:block}
.menu{display:flex;gap:4px}
.menu-item{padding:8px 14px;border-radius:9px;font-size:15px;color:#334155;transition:.2s}
.menu-item:hover{background:#eef2ff;color:var(--primary)}
.menu-item.active{background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff;font-weight:600}
.nav-auth{display:flex;gap:10px;align-items:center}

/* 按钮 */
.btn{display:inline-block;padding:9px 20px;border-radius:10px;font-size:15px;font-weight:600;border:none;cursor:pointer;transition:.2s;text-align:center}
.btn-primary{background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff}
.btn-primary:hover{opacity:.92;transform:translateY(-1px)}
.btn-secondary{background:linear-gradient(135deg,#0891b2,#06b6d4);color:#fff}
.btn-ghost{background:#f1f5f9;color:#334155}
.btn-ghost:hover{background:#e2e8f0}
.btn-outline{background:transparent;border:2px solid rgba(255,255,255,.8);color:#fff}
.btn-lg{padding:13px 30px;font-size:16px}
.btn-block{width:100%;padding:12px}

/* Hero */
.hero{background:linear-gradient(135deg,#312e81 0%,#4f46e5 45%,#7c3aed 100%);color:#fff;padding:72px 24px 64px}
.hero-inner{max-width:1180px;margin:0 auto;display:flex;gap:48px;align-items:center;flex-wrap:wrap}
.hero-text{flex:1.2;min-width:300px}
.hero-tag{display:inline-block;background:rgba(255,255,255,.15);border:1px solid rgba(255,255,255,.3);padding:5px 14px;border-radius:20px;font-size:13px;margin-bottom:18px}
.hero h1{font-size:42px;font-weight:800;margin-bottom:16px}
.grad-text{background:linear-gradient(90deg,#67e8f9,#c084fc,#f0abfc);-webkit-background-clip:text;background-clip:text;color:transparent}
.hero-sub{font-size:17px;opacity:.9;max-width:520px;margin-bottom:28px}
.hero-cta{display:flex;gap:14px}
.hero-card{flex:0.8;min-width:280px;background:rgba(255,255,255,.12);border:1px solid rgba(255,255,255,.25);backdrop-filter:blur(8px);border-radius:16px;padding:24px}
.hc-title{font-size:17px;font-weight:700;margin-bottom:14px}
.hc-item{display:flex;align-items:center;gap:9px;font-size:14px;opacity:.95;margin-bottom:10px}
.hc-dot{width:9px;height:9px;border-radius:50%;display:inline-block}

/* Section */
.section{max-width:1180px;margin:0 auto;padding:56px 24px}
.section-alt{background:#fff;border-top:1px solid var(--border);border-bottom:1px solid var(--border);max-width:none}
.section-alt>.section-title,.section-alt>.grid-3,.section-alt>.empty-tip{max-width:1180px;margin-left:auto;margin-right:auto}
.section-title{text-align:center;margin-bottom:36px}
.section-title h2{font-size:30px;font-weight:800;margin-bottom:6px}
.section-title p{color:var(--muted);font-size:15px}

/* 卡片 */
.grid-3{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:20px}
.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:24px;box-shadow:var(--shadow);transition:.25s}
.card:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg)}
.card-icon{width:52px;height:52px;border-radius:13px;display:flex;align-items:center;justify-content:center;font-size:24px;margin-bottom:14px}
.card h3{font-size:18px;margin-bottom:8px}
.card p{color:var(--muted);font-size:14px}

/* 流程 */
.flow{display:flex;align-items:stretch;justify-content:center;gap:16px;flex-wrap:wrap;max-width:1180px;margin:0 auto;padding:0 24px 56px}
.flow-step{flex:1;min-width:180px;max-width:240px;background:var(--card);border-radius:var(--radius);padding:22px;box-shadow:var(--shadow);text-align:center}
.flow-num{width:44px;height:44px;margin:0 auto 10px;border-radius:12px;background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:16px}
.flow-step h4{margin-bottom:6px}
.flow-step p{color:var(--muted);font-size:13px}
.flow-arrow{align-self:center;font-size:24px;color:#c4b5fd;font-weight:700}

/* CTA */
.cta-band{background:linear-gradient(135deg,#1e1b4b,#4f46e5);color:#fff;text-align:center;padding:56px 24px}
.cta-band h2{font-size:28px;margin-bottom:22px}
.cta-band .btn{margin:0 8px}

/* 页头 */
.page-head{background:linear-gradient(135deg,#312e81,#4f46e5 60%,#7c3aed);color:#fff;padding:48px 24px 44px;text-align:center}
.page-head h1{font-size:32px;margin-bottom:8px}
.page-head p{opacity:.88;font-size:15px}

/* 筛选 */
.filter-bar{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:26px;background:var(--card);padding:16px;border-radius:var(--radius);border:1px solid var(--border);box-shadow:var(--shadow)}
.filter-bar input,.filter-bar select{padding:10px 14px;border:1px solid var(--border);border-radius:10px;background:#f8fafc;min-width:160px;flex:1}
.filter-bar .btn{flex:0 0 auto}

/* 期刊卡片 */
.j-card .j-head{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:8px}
.j-card h3{font-size:17px}
.j-meta{display:flex;gap:16px;color:var(--muted);font-size:13px;margin-bottom:8px;flex-wrap:wrap}
.j-sum{font-size:14px;color:#475569}
.badge{font-size:12px;padding:3px 10px;border-radius:14px;font-weight:600}
.badge-core{background:#fef2f2;color:#dc2626}
.badge-normal{background:#f1f5f9;color:#475569}

/* 空态与状态 */
.empty-tip{grid-column:1/-1;text-align:center;color:var(--muted);padding:48px 0;font-size:15px}
.status-tip{color:var(--muted);font-size:13px;margin-top:8px;min-height:20px}

/* 智能推荐 */
.reco-wrap{display:flex;gap:24px;align-items:flex-start;flex-wrap:wrap}
.reco-form{flex:0.9;min-width:300px}
.reco-form label{display:block;font-size:14px;font-weight:600;margin:14px 0 6px;color:#334155}
.reco-form input,.reco-form select{width:100%;padding:11px 14px;border:1px solid var(--border);border-radius:10px;background:#f8fafc}
.reco-form .btn{margin-top:18px}
.reco-result{flex:1.2;min-width:300px}
.reco-out{background:#f8fafc;border-radius:10px;padding:16px;color:#334155;font-size:14px;line-height:1.9;white-space:pre-wrap;min-height:120px}

/* AI 对话 */
.ai-wrap{max-width:880px}
.ai-panel{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);box-shadow:var(--shadow-lg);overflow:hidden}
.ai-toolbar{display:flex;align-items:center;gap:12px;padding:12px 16px;border-bottom:1px solid var(--border);background:#f8fafc}
.ai-model-select{padding:8px 12px;border:1px solid var(--border);border-radius:9px;background:#fff}
.ai-toolbar .status-tip{margin:0;flex:1}
.ai-chat{height:480px;overflow-y:auto;padding:18px;display:flex;flex-direction:column;gap:12px;background:#fafbff}
.ai-msg{max-width:82%;padding:12px 16px;border-radius:14px;font-size:14px;line-height:1.8;white-space:pre-wrap;word-break:break-word}
.ai-msg-bot{background:#fff;border:1px solid var(--border);border-top-left-radius:4px;align-self:flex-start;box-shadow:var(--shadow)}
.ai-msg-user{background:linear-gradient(135deg,var(--primary),var(--primary2));color:#fff;border-top-right-radius:4px;align-self:flex-end}
.ai-input{display:flex;gap:10px;padding:14px 16px;border-top:1px solid var(--border)}
.ai-input input{flex:1;padding:11px 14px;border:1px solid var(--border);border-radius:10px}

/* 论坛 */
.forum-bar{display:flex;align-items:center;justify-content:space-between;margin-bottom:18px}
.forum-title{font-size:18px;font-weight:700}
.card-list{display:flex;flex-direction:column;gap:12px}
.topic-row .topic-title{font-size:15px;font-weight:600;margin-bottom:4px}
.topic-meta{font-size:12px;color:var(--muted)}

/* 登录注册 */
.auth-wrap{display:flex;justify-content:center;padding:56px 24px}
.auth-card{width:420px;background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:34px;box-shadow:var(--shadow-lg)}
.auth-card h2{font-size:24px;margin-bottom:4px}
.auth-sub{color:var(--muted);font-size:14px;margin-bottom:22px}
.auth-card label{display:block;font-size:14px;font-weight:600;margin:14px 0 6px;color:#334155}
.auth-card input{width:100%;padding:11px 14px;border:1px solid var(--border);border-radius:10px;background:#f8fafc}
.auth-card .btn{margin-top:20px}
.auth-alt{margin-top:16px;font-size:14px;color:var(--muted);text-align:center}
.auth-alt a{color:var(--primary);font-weight:600}
.auth-tip{margin-top:18px;font-size:13px;color:#a16207;background:#fefce8;border:1px solid #fde68a;border-radius:9px;padding:9px 12px;text-align:center}

/* Footer */
.footer{background:#1e293b;color:#94a3b8;padding:40px 24px}
.footer-inner{max-width:1180px;margin:0 auto;text-align:center}
.footer-brand{font-size:16px;color:#e2e8f0;font-weight:700;margin-bottom:12px}
.footer-links{display:flex;gap:22px;justify-content:center;margin-bottom:14px;font-size:14px;flex-wrap:wrap}
.footer-links a:hover{color:#fff}
.footer-meta{font-size:13px}

@media(max-width:720px){
  .nav-inner{flex-wrap:wrap;height:auto;padding:12px 16px;gap:8px}
  .menu{order:3;width:100%;overflow-x:auto;white-space:nowrap;justify-content:flex-start}
  .hero h1{font-size:30px}
  .hero-inner{gap:28px}
  .flow{flex-direction:column;align-items:center}
  .flow-arrow{transform:rotate(90deg)}
}