/* ============================================================
   蓝白高级主题覆盖层（Blue-White Premium）
   叠加于 style.css 之上，纯 CSS 覆盖、不改原文件：
   青绿 → 学院蓝 #1557A0 / 暖纸 → 浅蓝灰 / 深墨侧栏 → 深学院蓝
   与登录页学院蓝品牌统一
   ============================================================ */

:root {
  /* 主调：青绿 → 学院蓝 */
  --primary: #1557A0;
  --primary-light: #d3e3f7;
  --primary-dark: #0d3d77;
  --primary-soft: #eaf1fb;

  /* 辅助琥珀微调（更贴合冷调） */
  --amber: #b97a1e;
  --amber-light: #fdf0dd;
  --amber-soft: #fdf8ee;

  /* 中性：暖纸 → 浅蓝灰；侧栏深墨 → 深学院蓝 */
  --paper: #f4f7fb;
  --paper-deep: #e9eff8;
  --surface: #ffffff;
  --ink: #0a2c57;
  --ink-soft: #123a6e;
  --ink-mute: #4b5c77;

  --gray-50: #f8fafd;
  --gray-100: #eef2f8;
  --gray-200: #dfe7f1;
  --gray-300: #c8d4e5;
  --gray-400: #9db0c9;
  --gray-500: #6b7f9c;
  --gray-600: #4a5b77;
  --gray-700: #34425c;
  --gray-800: #232f47;
  --gray-900: #16202f;

  /* 阴影：暖调 → 冷蓝调 */
  --shadow: 0 1px 2px rgba(21,87,160,0.06), 0 1px 3px rgba(21,87,160,0.04);
  --shadow-md: 0 4px 12px rgba(21,87,160,0.08), 0 2px 4px rgba(21,87,160,0.04);
  --shadow-lg: 0 12px 32px rgba(21,87,160,0.12), 0 4px 12px rgba(21,87,160,0.06);
}

/* 主背景：暖纸网格 → 冷蓝网格 */
body {
  background-color: var(--paper);
  background-image:
    linear-gradient(rgba(21,87,160,0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(21,87,160,0.05) 1px, transparent 1px);
}

/* 写死的青绿焦点环 → 学院蓝 */
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus,
.toolbar input:focus,
.toolbar select:focus,
.form-group-full input:focus,
.form-group-full select:focus,
.form-group-full textarea:focus {
  box-shadow: 0 0 0 3px rgba(21,87,160,0.14);
}

/* 侧栏：深蓝底上亮蓝激活高亮 */
.sidebar,
.student-sidebar {
  box-shadow: 4px 0 24px rgba(10,44,87,0.20);
}
.nav-item.active {
  background: linear-gradient(90deg, rgba(30,111,208,0.55), rgba(30,111,208,0.14));
  border-left-color: #7db4f0;
}
.nav-item.active::after { background: #7db4f0; }
.nav-item.active .nav-icon { color: #a8ccf7; }

/* 侧栏品牌副标提亮 */
.sidebar-logo .logo-text small { color: rgba(255,255,255,0.52); }

/* 顶栏细阴影 → 蓝调 */
.topbar { box-shadow: 0 1px 3px rgba(21,87,160,0.05); }

/* 主按钮悬停阴影 → 蓝 */
.btn-primary:hover { box-shadow: 0 2px 8px rgba(21,87,160,0.3); }