/* ============================================================
   昭昭医考 Nexus xb06 · 工业精密版重启 (Official Standard)
   视觉规范：#4A6FA5 | 4px 凌厉圆角 | 1px 细线 | 全站去粗
   ============================================================ */

:root {
  --primary: #4A6FA5;           /* 智库蓝 */
  --primary-deep: #2C4066;      /* 导航/重色 */
  --primary-soft: #F0F4F7;      
  --success: #0E9384;           /* 智库绿 */
  --ink: #111827;               /* 标题黑 */
  --slate-600: #4B5563;         /* 正文灰 */
  --slate-400: #9CA3AF;         /* 辅助灰 */
  --border-line: #E5E7EB;       /* 1px 工业线 */
  --radius-pro: 4px;            /* 核心：4px 凌厉圆角 */

  /* 语义色 */
  --danger: #D92D20;
  --warning: #F79009;
  --bg: #F3F4F6;

  /* 字体体系 */
  --font-main: "Inter", "PingFang SC", -apple-system, "Segoe UI", sans-serif;
  --header-h: 60px;
}

* { box-sizing: border-box; -webkit-font-smoothing: antialiased; }

body {
  margin: 0; padding: 0;
  font-family: var(--font-main);
  background-color: #F3F4F6 !important;
  color: var(--slate-600);
  line-height: 1.5;
  font-weight: 400 !important; /* 全站去粗 */
}

h1, h2, h3, h4, h5, h6 { font-weight: 700 !important; color: var(--ink); }
a { color: var(--primary); text-decoration: none; }
a:hover { color: var(--primary-deep); }

/* ============================================================
   顶部导航 (Deep Header)
   ============================================================ */
.ec-topnav {
  background: var(--primary-deep) !important;
  height: var(--header-h); display: flex; align-items: center; padding: 0 40px;
  position: sticky; top: 0; z-index: 1000;
}

.ec-topnav .nav-brand {
  display: flex; align-items: center; gap: 10px; flex-shrink: 0;
  text-decoration: none;
}

.ec-topnav .nav-brand img { height: 28px; filter: brightness(0) invert(1); }

.ec-topnav .nav-brand span {
  font-size: 13px; font-weight: 900; color: #fff; letter-spacing: 1px;
}

.ec-topnav .nav-links {
  flex: 1; display: flex; justify-content: center; gap: 4px;
}

.ec-topnav .nav-links a {
  color: rgba(255,255,255,0.7) !important; font-size: 13px; font-weight: 600;
  padding: 0 20px; line-height: var(--header-h); text-decoration: none;
  transition: 0.2s; position: relative;
}

.ec-topnav .nav-links a:hover { color: #fff !important; }
.ec-topnav .nav-links a.active {
  color: #fff !important; background: var(--primary);
}

.ec-topnav .nav-right {
  display: flex; align-items: center; gap: 12px;
}

.ec-topnav .nav-right .user-avatar img {
  width: 32px; height: 32px; border-radius: 50%;
  border: 1px solid rgba(255,255,255,0.2);
  object-fit: cover;
}

.ec-topnav .nav-right .user-name {
  color: #fff !important; font-weight: 600 !important;
  font-size: 13px !important; text-decoration: none;
}

.ec-topnav .btn-nexus {
  background: transparent; border: 1px solid rgba(255,255,255,0.3);
  color: #fff !important; padding: 6px 16px; border-radius: 4px;
  font-size: 12px; font-weight: 700; text-decoration: none; transition: 0.2s;
}
.ec-topnav .btn-nexus:hover { background: rgba(255,255,255,0.1); }

/* ============================================================
   页面容器
   ============================================================ */
.page-wrap { max-width: 1200px; margin: 0 auto; padding: 40px; }

/* ============================================================
   Hero Branding
   ============================================================ */
.academic-hero {
  text-align: center; margin-bottom: 48px;
}
.academic-main-title {
  font-size: 32px; font-weight: 800 !important; color: var(--ink);
  letter-spacing: 2px; margin-bottom: 8px;
}
.academic-sub-text {
  font-size: 13px; color: var(--slate-400); font-weight: 600;
  letter-spacing: 1px; text-transform: uppercase;
}

/* ============================================================
   工业统计网格
   ============================================================ */
.stats-grid-xb {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--border-line); border: 1px solid var(--border-line);
  border-radius: var(--radius-pro); overflow: hidden; margin-bottom: 48px;
}
.stat-cell { background: #fff; padding: 24px; text-align: center; }
.stat-cell .label {
  display: block; font-size: 11px; font-weight: 800; color: var(--slate-400);
  text-transform: uppercase; margin-bottom: 8px;
}
.stat-cell .value {
  font-size: 28px; font-weight: 900; color: var(--primary-deep);
  font-variant-numeric: tabular-nums;
}
.stat-cell.green .value { color: var(--success); }

/* ============================================================
   实训矩阵 (4列扁平卡片)
   ============================================================ */
.matrix-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 60px; }

.matrix-card {
  background: #fff; border: 1px solid var(--border-line);
  border-radius: var(--radius-pro); padding: 16px;
  display: flex; flex-direction: column; transition: 0.2s;
  min-height: 116px; text-decoration: none; color: inherit;
}
.matrix-card:hover { border-color: var(--primary); box-shadow: 0 4px 12px rgba(0,0,0,0.04); }
.matrix-card:hover .btn-start-action { background: var(--primary-deep); }

.matrix-core { display: flex; align-items: center; gap: 12px; flex: 1; margin-bottom: 12px; }
.matrix-icon {
  width: 32px; height: 32px; border-radius: 2px;
  display: flex; align-items: center; justify-content: center;
  font-size: 16px; flex-shrink: 0;
}
.matrix-name { font-size: 14px; font-weight: 700 !important; color: var(--ink); }
.matrix-meta { font-size: 11px; color: var(--slate-400); margin-top: 2px; }

.btn-start-action {
  display: block; width: 100%;
  background: var(--primary); color: #fff !important; border: none;
  border-radius: 2px; padding: 6px; font-size: 11px; font-weight: 800;
  text-align: center; letter-spacing: 1px; cursor: pointer; transition: 0.2s;
}

/* ============================================================
   试卷中心 (2列宽幅)
   ============================================================ */
.paper-shelf-2col { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 60px; }

.paper-card-wide {
  background: #fff; border: 1px solid var(--border-line);
  border-radius: var(--radius-pro); padding: 32px;
  display: flex; gap: 24px; transition: 0.2s; text-decoration: none; color: inherit;
}
.paper-card-wide:hover { border-color: var(--primary); }
.paper-card-wide:hover .btn-paper-go { background: var(--primary-deep); }

.paper-badge { 
  width: 48px; height: 60px; background: var(--primary-soft); color: var(--primary);
  border-radius: 2px; display: flex; align-items: center; justify-content: center;
  font-size: 24px; flex-shrink: 0;
}

.paper-info { flex: 1; }
.paper-title {
  font-size: 16px; font-weight: 700 !important; color: var(--ink);
  margin-bottom: 8px; line-height: 1.4;
}
.paper-desc {
  font-size: 13px; color: var(--slate-600); line-height: 1.6;
  margin-bottom: 20px;
}
.paper-meta-bar {
  display: flex; gap: 16px; font-size: 11px; font-weight: 700; color: var(--slate-400);
}

.btn-paper-go {
  width: 100%; height: 40px; background: var(--primary); color: #fff !important;
  border: none; border-radius: 2px; font-size: 13px; font-weight: 800;
  margin-top: 20px; cursor: pointer; transition: 0.2s;
}

/* ============================================================
   底部面板 (排行/问答)
   ============================================================ */
.footer-panel {
  background: #fff; border: 1px solid var(--border-line);
  border-radius: var(--radius-pro); overflow: hidden;
}
.panel-head {
  padding: 14px 20px; background: var(--primary-soft);
  border-bottom: 1px solid var(--border-line);
  font-size: 13px; font-weight: 800; color: var(--primary-deep);
}
.panel-item {
  padding: 12px 20px; border-bottom: 1px solid var(--border-line);
  display: flex; align-items: center; gap: 16px;
}
.panel-item:last-child { border-bottom: none; }

/* ============================================================
   大一统页脚
   ============================================================ */
.nexus-footer {
  margin-top: 100px; background: #fff; border-top: 1px solid var(--border-line);
  padding: 60px 0 40px;
}
.footer-container {
  max-width: 1200px; margin: 0 auto; padding: 0 40px;
  display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 40px;
}
.footer-col-title {
  font-size: 13px; font-weight: 800; color: var(--ink);
  margin-bottom: 24px; text-transform: uppercase; letter-spacing: 1px;
}
.footer-link-group { display: flex; flex-direction: column; gap: 12px; }
.footer-link-group a, .footer-info-item {
  text-decoration: none; color: var(--slate-400); font-size: 13px; transition: 0.2s;
}
.footer-link-group a:hover { color: var(--primary); }
.footer-bottom-bar {
  max-width: 1200px; margin: 40px auto 0; padding: 24px 40px 0;
  border-top: 1px solid #F3F4F6; text-align: center;
  font-size: 11px; color: var(--slate-400); letter-spacing: 1px;
}

/* ============================================================
   响应式
   ============================================================ */
@media (max-width: 1024px) {
  .matrix-grid { grid-template-columns: repeat(3, 1fr); }
  .paper-shelf-2col { grid-template-columns: 1fr; }
}
@media (max-width: 768px) {
  .ec-topnav { padding: 0 16px; }
  .ec-topnav .nav-links a { padding: 0 10px; font-size: 12px; }
  .page-wrap { padding: 24px 16px; }
  .stats-grid-xb { grid-template-columns: repeat(2, 1fr); }
  .matrix-grid { grid-template-columns: repeat(2, 1fr); }
  .academic-main-title { font-size: 24px; }
  .footer-container { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 480px) {
  .stats-grid-xb { grid-template-columns: repeat(2, 1fr); }
  .matrix-grid { grid-template-columns: 1fr; }
  .footer-container { grid-template-columns: 1fr; }
}