/* 学习互动吧 - 公共样式 */
:root {
  --primary: #4f6ef2;
  --primary-dark: #3d56c8;
  --primary-light: #eef1fe;
  --success: #22a06b;
  --warning: #e8890c;
  --danger: #d64545;
  --bg: #f3f5fa;
  --card: #ffffff;
  --text: #1f2430;
  --muted: #8a91a5;
  --border: #e4e8f0;
  --radius: 10px;
  --shadow: 0 2px 10px rgba(31, 36, 48, .06);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
  font-family: "Microsoft YaHei", "PingFang SC", system-ui, sans-serif;
  background: var(--bg); color: var(--text); font-size: 14px;
}
a { color: var(--primary); text-decoration: none; }
button { cursor: pointer; font-family: inherit; }
input, select, textarea {
  font-family: inherit; font-size: 14px; padding: 8px 12px;
  border: 1px solid var(--border); border-radius: 8px; outline: none; background: #fff; color: var(--text);
}
input:focus, select:focus, textarea:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79,110,242,.12); }
textarea { resize: vertical; min-height: 80px; }

/* ---------- 登录页 ---------- */
.login-wrap {
  min-height: 100vh; display: flex; align-items: center; justify-content: center;
  background: linear-gradient(135deg, #4f6ef2 0%, #6a5cf0 50%, #8b5cf6 100%);
  padding: 24px 16px; overflow-y: auto;
}
.login-card {
  width: 920px; max-width: 100%; background: #fff; border-radius: 18px; display: flex; overflow: hidden;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
}
.login-left { flex: 1.1; padding: 48px 40px; color: #fff; background: linear-gradient(160deg, rgba(255,255,255,.14), rgba(255,255,255,.04)); display: flex; flex-direction: column; justify-content: center; }
.login-left h1 { font-size: 32px; margin-bottom: 10px; letter-spacing: 2px; }
.login-left p { opacity: .85; line-height: 1.8; font-size: 14px; }
.login-features { margin-top: 28px; display: grid; grid-template-columns: 1fr 1fr; gap: 10px; font-size: 13px; opacity: .92; }
.login-features span { background: rgba(255,255,255,.15); padding: 8px 12px; border-radius: 8px; }
.login-right { flex: 1; padding: 48px 40px; }
.login-tabs { display: flex; gap: 8px; margin-bottom: 24px; background: var(--bg); padding: 5px; border-radius: 10px; }
.login-tabs button { flex: 1; padding: 10px; border: none; background: transparent; border-radius: 8px; font-size: 14px; color: var(--muted); cursor: pointer; }
.login-tabs button.active { background: #fff; color: var(--primary); font-weight: 600; box-shadow: var(--shadow); }
.form-item { margin-bottom: 18px; }
.form-item label { display: block; margin-bottom: 6px; color: #444; font-size: 13px; }
.form-item input { width: 100%; padding: 11px 14px; }
.btn-primary {
  width: 100%; padding: 12px; border: none; border-radius: 8px;
  background: var(--primary); color: #fff; font-size: 15px; transition: .2s;
}
.btn-primary:hover { background: var(--primary-dark); }
.login-tip { margin-top: 18px; font-size: 12px; color: var(--muted); text-align: center; line-height: 1.8; }

/* ---------- 主框架 ---------- */
.layout { display: flex; min-height: 100vh; }
.sidebar {
  width: 220px; background: #232a3d; color: #c6cbe0; flex-shrink: 0;
  display: flex; flex-direction: column; position: sticky; top: 0; height: 100vh;
}
.logo { padding: 22px 20px; font-size: 18px; font-weight: 700; color: #fff; border-bottom: 1px solid rgba(255,255,255,.08); letter-spacing: 1px; }
.logo small { display: block; font-size: 11px; color: #7d87a8; font-weight: 400; margin-top: 4px; letter-spacing: 0; }
.menu { flex: 1; overflow-y: auto; padding: 12px 10px; }
.menu-item {
  display: flex; align-items: center; gap: 10px; padding: 11px 14px; margin-bottom: 3px;
  border-radius: 8px; cursor: pointer; font-size: 14px; transition: .15s; position: relative;
}
.menu-item:hover { background: rgba(255,255,255,.07); color: #fff; }
.menu-item.active { background: var(--primary); color: #fff; font-weight: 500; }
.menu-item .badge { position: absolute; right: 12px; top: 50%; transform: translateY(-50%); background: var(--danger); color: #fff; font-size: 11px; min-width: 18px; height: 18px; line-height: 18px; text-align: center; border-radius: 9px; padding: 0 5px; }
.sidebar-footer { padding: 14px; border-top: 1px solid rgba(255,255,255,.08); font-size: 13px; }
.sidebar-footer .user { display: flex; align-items: center; gap: 8px; margin-bottom: 10px; color: #fff; }
.avatar { width: 32px; height: 32px; border-radius: 50%; background: var(--primary); color: #fff; display: inline-flex; align-items: center; justify-content: center; font-size: 14px; flex-shrink: 0; }
.sidebar-footer .ops { display: flex; gap: 8px; }
.sidebar-footer .ops button { flex: 1; padding: 6px; border: 1px solid rgba(255,255,255,.2); background: transparent; color: #c6cbe0; border-radius: 6px; font-size: 12px; }
.sidebar-footer .ops button:hover { background: rgba(255,255,255,.1); color: #fff; }

.main { flex: 1; padding: 22px 26px; min-width: 0; }
.page-header { margin-bottom: 18px; display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; }
.page-header h2 { font-size: 20px; }
.page-header .sub { color: var(--muted); font-size: 13px; margin-top: 4px; }

/* ---------- 组件 ---------- */
.card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px; margin-bottom: 18px; }
.card h3 { font-size: 15px; margin-bottom: 14px; padding-left: 10px; border-left: 3px solid var(--primary); }
.stat-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(170px, 1fr)); gap: 14px; margin-bottom: 18px; }
.stat-card { background: var(--card); border-radius: var(--radius); box-shadow: var(--shadow); padding: 18px; }
.stat-card .num { font-size: 28px; font-weight: 700; color: var(--primary); }
.stat-card .label { color: var(--muted); font-size: 13px; margin-top: 4px; }
.stat-card.warn .num { color: var(--warning); }
.stat-card.danger .num { color: var(--danger); }
.stat-card.ok .num { color: var(--success); }

.toolbar { display: flex; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; align-items: center; }
.toolbar input, .toolbar select { width: auto; }
.btn { padding: 8px 16px; border: 1px solid var(--border); background: #fff; border-radius: 8px; font-size: 13px; transition: .15s; }
.btn:hover { border-color: var(--primary); color: var(--primary); }
.btn.primary { background: var(--primary); border-color: var(--primary); color: #fff; }
.btn.primary:hover { background: var(--primary-dark); }
.btn.success { background: var(--success); border-color: var(--success); color: #fff; }
.btn.danger { background: var(--danger); border-color: var(--danger); color: #fff; }
.btn.warning { background: var(--warning); border-color: var(--warning); color: #fff; }
.btn.sm { padding: 4px 10px; font-size: 12px; border-radius: 6px; }
.btn.link { background: transparent; border: none; color: var(--primary); padding: 0; }
.btn.link:hover { text-decoration: underline; color: var(--primary-dark); }
.btn:disabled { opacity: .5; cursor: not-allowed; }

table.table { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.table th { text-align: left; padding: 10px 12px; background: #f7f8fc; color: #5a6178; font-weight: 600; white-space: nowrap; border-bottom: 1px solid var(--border); }
.table td { padding: 10px 12px; border-bottom: 1px solid #f0f2f8; vertical-align: top; }
.table tr:hover td { background: #fafbff; }
.table .ops { display: flex; gap: 6px; flex-wrap: wrap; }
.tag { display: inline-block; padding: 2px 10px; border-radius: 20px; font-size: 12px; }
.tag.green { background: #e6f6ef; color: var(--success); }
.tag.orange { background: #fdf1e0; color: var(--warning); }
.tag.red { background: #fdeaea; color: var(--danger); }
.tag.danger { background: #fdeaea; color: var(--danger); }
.tag.blue { background: var(--primary-light); color: var(--primary); }
.tag.gray { background: #eef0f5; color: #6b7280; }

.empty { text-align: center; color: var(--muted); padding: 40px 0; font-size: 14px; }

/* 弹窗 */
.modal-mask { position: fixed; inset: 0; background: rgba(20,24,36,.45); display: flex; align-items: center; justify-content: center; z-index: 300; }
.modal { background: #fff; border-radius: 12px; width: 560px; max-width: 92vw; max-height: 88vh; display: flex; flex-direction: column; box-shadow: 0 12px 40px rgba(0,0,0,.2); }
.modal.lg { width: 760px; }
.modal-head { padding: 16px 20px; border-bottom: 1px solid var(--border); display: flex; justify-content: space-between; align-items: center; }
.modal-head h3 { font-size: 16px; }
.modal-head .close { border: none; background: none; font-size: 20px; color: var(--muted); }
.modal-body { padding: 20px; overflow-y: auto; }
.modal-foot { padding: 14px 20px; border-top: 1px solid var(--border); display: flex; justify-content: flex-end; gap: 10px; }
.grid2 { display: grid; grid-template-columns: 1fr 1fr; gap: 0 16px; }
.grid2 .full, .form-item.full { grid-column: 1 / -1; }
.form-item label { font-size: 13px; color: #555; }
.form-item input, .form-item select, .form-item textarea { width: 100%; }

/* 消息红点 & toast */
.toast { position: fixed; top: 24px; left: 50%; transform: translateX(-50%); background: #2c3245; color: #fff; padding: 10px 22px; border-radius: 8px; font-size: 14px; z-index: 400; box-shadow: 0 6px 20px rgba(0,0,0,.25); animation: fadein .2s; }
.toast.err { background: var(--danger); }
.toast.ok { background: var(--success); }
@keyframes fadein { from { opacity: 0; transform: translate(-50%, -8px); } to { opacity: 1; transform: translate(-50%, 0); } }

.msg-item { display: flex; gap: 12px; padding: 14px; border-bottom: 1px solid #f0f2f8; align-items: flex-start; }
.msg-item.unread { background: #f6f8ff; }
.msg-item .icon { width: 38px; height: 38px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 18px; flex-shrink: 0; background: var(--primary-light); }
.msg-item .body { flex: 1; }
.msg-item .title { font-weight: 600; font-size: 14px; }
.msg-item .content { color: #555; margin-top: 3px; line-height: 1.6; }
.msg-item .time { color: var(--muted); font-size: 12px; margin-top: 4px; }

.notice-item { padding: 14px 0; border-bottom: 1px solid #f0f2f8; }
.notice-item .n-title { font-weight: 600; }
.notice-item .n-content { color: #555; margin-top: 6px; line-height: 1.7; white-space: pre-wrap; }
.notice-item .n-meta { color: var(--muted); font-size: 12px; margin-top: 6px; }

progress-bar { display: block; }
.pbar { height: 8px; background: #eef0f5; border-radius: 4px; overflow: hidden; display: flex; }
.pbar span { height: 100%; }
.pbar .s-done { background: var(--success); }
.pbar .s-doing { background: var(--warning); }
.pbar .s-todo { background: #c9cede; }

.kv { display: grid; grid-template-columns: 110px 1fr; gap: 10px 14px; font-size: 14px; }
.kv .k { color: var(--muted); }
.pre-line { white-space: pre-line; line-height: 1.8; }

/* 手机专用元素：电脑端默认隐藏（媒体查询内再覆盖显示） */
.mobile-menu-btn, .sidebar-mask { display: none; }

@media (max-width: 900px) {
  .login-card { flex-direction: column; }
  .login-left { display: none; }
  /* 手机端：侧边栏改为抽屉式 */
  .sidebar {
    width: 250px; position: fixed; left: 0; top: 0; z-index: 200;
    transform: translateX(-100%); transition: transform .25s ease;
    box-shadow: 4px 0 24px rgba(0,0,0,.2);
  }
  .sidebar.open { transform: translateX(0); }
  .sidebar .logo, .menu-item span.txt, .sidebar-footer .user .info { display: block; }
  /* 汉堡按钮 */
  .mobile-menu-btn {
    display: flex; position: fixed; top: 10px; left: 10px; z-index: 150;
    width: 40px; height: 40px; align-items: center; justify-content: center;
    background: var(--primary); color: #fff; border: none; border-radius: 10px;
    font-size: 20px; box-shadow: 0 2px 8px rgba(79,110,242,.4);
  }
  /* 抽屉遮罩 */
  .sidebar-mask {
    display: none; position: fixed; inset: 0; background: rgba(0,0,0,.45); z-index: 190;
  }
  .sidebar-mask.show { display: block; }
  /* 主内容顶部留出汉堡按钮空间 */
  .main { padding-top: 60px; }
}
@media (max-width: 480px) {
  .main { padding: 60px 12px 14px; }
  .page-header h2 { font-size: 17px; }
  .page-header .sub { font-size: 12px; }
  .stat-grid { grid-template-columns: 1fr 1fr; }
  .card { padding: 14px; }
  .table-wrap, .table { overflow-x: auto; display: block; }
  .grid2 { grid-template-columns: 1fr; }
  .sc-grid { grid-template-columns: 1fr 1fr; }
}

/* ---------- AI 任务批改 ---------- */
.ai-uploader {
  border: 2px dashed var(--border); border-radius: 12px; padding: 26px; text-align: center;
  color: var(--muted); cursor: pointer; transition: .18s; background: #fafbff;
}
.ai-uploader:hover, .ai-uploader.drag { border-color: var(--primary); background: var(--primary-light); color: var(--primary); }
.ai-uploader .ui { font-size: 34px; display: block; margin-bottom: 8px; }
.ai-thumbs { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 12px; }
.ai-thumb { position: relative; width: 96px; height: 96px; border-radius: 10px; overflow: hidden; border: 1px solid var(--border); }
.ai-thumb img { width: 100%; height: 100%; object-fit: cover; }
.ai-thumb .rm {
  position: absolute; right: 4px; top: 4px; width: 20px; height: 20px; line-height: 18px; text-align: center;
  background: rgba(0,0,0,.55); color: #fff; border-radius: 50%; font-size: 12px; border: none;
}
.grade-hero { display: flex; gap: 20px; align-items: center; background: linear-gradient(120deg,#0ea5e9,#6366f1 60%,#8b5cf6); color:#fff; border-radius: 14px; padding: 20px 24px; margin-bottom: 16px; }
.grade-score-ring {
  width: 84px; height: 84px; border-radius: 50%; flex-shrink: 0;
  background: rgba(255,255,255,.18); display: flex; flex-direction: column; align-items: center; justify-content: center;
  border: 3px solid rgba(255,255,255,.55);
}
.grade-score-ring .gs { font-size: 24px; font-weight: 700; line-height: 1; }
.grade-score-ring .gt { font-size: 11px; opacity: .85; margin-top: 3px; }
.grade-hero .gh-body { flex: 1; }
.grade-hero .gh-level { font-size: 18px; font-weight: 700; margin-bottom: 6px; }
.grade-hero .gh-sum { font-size: 13.5px; line-height: 1.7; opacity: .95; }
.q-item { border: 1px solid var(--border); border-radius: 10px; padding: 14px 16px; margin-bottom: 10px; }

/* ---------- 风采展示 ---------- */
.sc-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(220px, 1fr)); gap: 16px; margin-top: 12px; }
.sc-card { background: #fff; border: 1px solid var(--border); border-radius: 14px; padding: 20px 16px; text-align: center; transition: all .2s; }
.sc-card:hover { transform: translateY(-3px); box-shadow: 0 10px 24px rgba(0,0,0,.08); border-color: var(--primary-light); }
.sc-avatar { width: 72px; height: 72px; border-radius: 50%; margin: 0 auto 12px; display: flex; align-items: center; justify-content: center; font-size: 32px; background: linear-gradient(135deg, var(--primary-light), #e0e7ff); overflow: hidden; }
.sc-avatar img { width: 100%; height: 100%; object-fit: cover; }
.sc-name { font-size: 16px; font-weight: 700; color: var(--text); }
.sc-sub { font-size: 12.5px; color: var(--primary); margin-top: 2px; font-weight: 600; }
.sc-desc { font-size: 13px; color: var(--muted); margin-top: 8px; line-height: 1.6; text-align: left; }
.sc-tag { display: inline-block; margin-top: 8px; font-size: 12px; color: #b45309; background: #fef3c7; padding: 3px 10px; border-radius: 999px; }

/* ---------- Tabs ---------- */
.tabs { display: flex; gap: 8px; margin-bottom: 16px; flex-wrap: wrap; }
.tab { padding: 8px 18px; border: 1px solid var(--border); background: #fff; border-radius: 999px; cursor: pointer; font-size: 14px; color: var(--muted); transition: all .15s; }
.tab:hover { border-color: var(--primary); color: var(--primary); }
.tab.active { background: var(--primary); color: #fff; border-color: var(--primary); }

/* ---------- 表单工具 ---------- */
.upload-row { display: flex; gap: 8px; align-items: center; }
.upload-row input { flex: 1; }
.form-section-title { display: flex; align-items: center; gap: 6px; font-size: 14px; font-weight: 700; color: var(--text); margin: 18px 0 10px; padding-bottom: 6px; border-bottom: 1px solid var(--border); }
.form-section-title .fi { font-size: 16px; }
.tip { font-size: 12px; color: var(--muted); margin-top: 6px; line-height: 1.6; }

/* ---------- 登录页高级感 ---------- */
.login-hero { position: fixed; inset: 0; z-index: 0; overflow: hidden; background: linear-gradient(135deg, #0f172a 0%, #1e293b 40%, #312e81 100%); }
.login-hero::before { content: ''; position: absolute; width: 600px; height: 600px; border-radius: 50%; background: radial-gradient(circle, rgba(99,102,241,.45), transparent 70%); top: -200px; left: -150px; animation: floatA 14s ease-in-out infinite; }
.login-hero::after { content: ''; position: absolute; width: 500px; height: 500px; border-radius: 50%; background: radial-gradient(circle, rgba(14,165,233,.4), transparent 70%); bottom: -150px; right: -100px; animation: floatB 18s ease-in-out infinite; }
@keyframes floatA { 0%,100% { transform: translate(0,0) scale(1); } 50% { transform: translate(80px,60px) scale(1.1); } }
@keyframes floatB { 0%,100% { transform: translate(0,0) scale(1); } 50% { transform: translate(-60px,-40px) scale(1.15); } }
.login-stars { position: absolute; inset: 0; background-image: radial-gradient(1px 1px at 20% 30%, rgba(255,255,255,.5), transparent), radial-gradient(1px 1px at 60% 70%, rgba(255,255,255,.4), transparent), radial-gradient(1.5px 1.5px at 80% 20%, rgba(255,255,255,.6), transparent), radial-gradient(1px 1px at 40% 80%, rgba(255,255,255,.35), transparent), radial-gradient(1px 1px at 90% 50%, rgba(255,255,255,.45), transparent); animation: twinkle 5s ease-in-out infinite; }
@keyframes twinkle { 0%,100% { opacity: .6; } 50% { opacity: 1; } }
.login-wrap { position: relative; z-index: 1; }
.q-item.q-right { border-left: 4px solid var(--success); background: #f7fdfa; }
.q-item.q-wrong { border-left: 4px solid var(--danger); background: #fff8f8; }
.q-item.q-partial { border-left: 4px solid var(--warning); background: #fffcf5; }
.q-item .q-head { display: flex; gap: 8px; align-items: center; margin-bottom: 8px; flex-wrap: wrap; }
.q-item .q-no { font-weight: 700; }
.q-item .q-body { font-size: 13.5px; line-height: 1.75; color: #444; }
.q-item .q-body b { color: var(--text); }
.ai-loading { text-align: center; padding: 40px 20px; color: var(--primary); }
.ai-loading .spin {
  width: 46px; height: 46px; border: 4px solid var(--primary-light); border-top-color: var(--primary);
  border-radius: 50%; animation: spin 0.9s linear infinite; margin: 0 auto 14px;
}
@keyframes spin { to { transform: rotate(360deg); } }
.ai-off {
  border: 1px dashed #f0c67b; background: #fffdf5; border-radius: 12px; padding: 26px; text-align: center; color: #9a6b08; line-height: 2;
}