:root {
  --bg: #f5f7fa;
  --card: #ffffff;
  --text: #1f2937;
  --muted: #6b7280;
  --line: #e5e7eb;
  --primary: #4f46e5;
  --primary-d: #4338ca;
  --ok: #16a34a;
  --ok-bg: #dcfce7;
  --bad: #dc2626;
  --bad-bg: #fee2e2;
  --warn: #d97706;
  --shadow: 0 1px 3px rgba(0,0,0,.08), 0 1px 2px rgba(0,0,0,.04);
  --radius: 12px;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
}

button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }
input, textarea { font-family: inherit; }

/* ===== 布局 ===== */
.app { max-width: 900px; margin: 0 auto; padding: 16px 16px 80px; }

.topbar {
  display: flex; align-items: center; gap: 12px;
  padding: 12px 16px; background: var(--card);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 50;
}
.topbar .avatar {
  width: 40px; height: 40px; border-radius: 50%;
  display: grid; place-items: center; font-size: 22px;
  background: #f1f5f9; flex-shrink: 0;
}
.topbar .who { flex: 1; min-width: 0; }
.topbar .who b { display: block; font-size: 15px; }
.topbar .who span { font-size: 12px; color: var(--muted); }
.topbar .logout { font-size: 13px; color: var(--muted); padding: 6px 10px; border-radius: 8px; }
.topbar .logout:hover { background: #f1f5f9; color: var(--text); }

/* ===== 卡片 ===== */
.card {
  background: var(--card); border-radius: var(--radius);
  box-shadow: var(--shadow); padding: 16px; margin-bottom: 14px;
}
.card h2 { margin: 0 0 12px; font-size: 17px; }
.card h3 { margin: 0 0 10px; font-size: 15px; }

.muted { color: var(--muted); }
.small { font-size: 13px; }
.center { text-align: center; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 6px;
  padding: 11px 18px; border-radius: 10px;
  background: var(--primary); color: #fff; font-size: 15px; font-weight: 500;
  transition: transform .06s, background .15s;
}
.btn:active { transform: scale(.97); }
.btn:hover { background: var(--primary-d); }
.btn:disabled { background: #c7c7d1; cursor: not-allowed; }
.btn-ghost { background: #fff; color: var(--text); border: 1.5px solid var(--line); }
.btn-ghost:hover { background: #f9fafb; }
.btn-lg { padding: 14px 26px; font-size: 17px; border-radius: 12px; }
.btn-sm { padding: 7px 13px; font-size: 13px; border-radius: 8px; }
.btn-block { width: 100%; }

/* ===== 登录 ===== */
.login-wrap { min-height: 100vh; display: grid; place-items: center; padding: 20px; }
.login-box { width: 100%; max-width: 380px; }
.login-box h1 { text-align: center; font-size: 26px; margin: 0 0 6px; }
.login-box .sub { text-align: center; color: var(--muted); font-size: 14px; margin-bottom: 22px; }
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.field input, .field textarea {
  width: 100%; padding: 12px 14px; font-size: 15px;
  border: 1.5px solid var(--line); border-radius: 10px;
  background: #fff; color: var(--text); outline: none;
}
.field input:focus, .field textarea:focus { border-color: var(--primary); }
.err { color: var(--bad); font-size: 13px; min-height: 20px; margin: 4px 0 10px; }

.quick-login { display: grid; grid-template-columns: repeat(2,1fr); gap: 8px; margin-top: 8px; }
.quick-login button {
  padding: 11px; border-radius: 10px; border: 1.5px solid var(--line);
  background: #fff; font-size: 14px; display: flex; align-items: center; gap: 6px; justify-content: center;
}
.quick-login button:hover { border-color: var(--primary); background: #f5f5ff; }

/* ===== 统计块 ===== */
.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(90px,1fr)); gap: 10px; }
.stat { background: #f9fafb; border-radius: 10px; padding: 12px 8px; text-align: center; }
.stat b { display: block; font-size: 22px; line-height: 1.3; }
.stat span { font-size: 12px; color: var(--muted); }
.stat.ok b { color: var(--ok); }
.stat.bad b { color: var(--bad); }

/* ===== 进度条 ===== */
.progress { height: 8px; background: #e5e7eb; border-radius: 4px; overflow: hidden; }
.progress > i { display: block; height: 100%; background: var(--primary); border-radius: 4px; transition: width .3s; }
.progress.ok > i { background: var(--ok); }

/* ===== 题目 ===== */
.q-stem { font-size: 17px; line-height: 1.75; margin-bottom: 14px; white-space: pre-wrap; }
.opt-list { display: flex; flex-direction: column; gap: 8px; }
.opt {
  display: flex; align-items: flex-start; gap: 10px; width: 100%;
  padding: 12px 14px; border: 1.5px solid var(--line); border-radius: 10px;
  background: #fff; text-align: left; font-size: 15px; line-height: 1.6;
}
.opt:hover:not(:disabled) { border-color: var(--primary); background: #f8f8ff; }
.opt .tag {
  flex-shrink: 0; width: 24px; height: 24px; border-radius: 50%;
  background: #f1f5f9; display: grid; place-items: center;
  font-size: 13px; font-weight: 600; color: var(--muted);
}
.opt.sel { border-color: var(--primary); background: #f0f0ff; }
.opt.sel .tag { background: var(--primary); color: #fff; }
.opt.right { border-color: var(--ok); background: var(--ok-bg); }
.opt.right .tag { background: var(--ok); color: #fff; }
.opt.wrong { border-color: var(--bad); background: var(--bad-bg); }
.opt.wrong .tag { background: var(--bad); color: #fff; }
.opt:disabled { cursor: default; }

.q-actions { display: flex; gap: 10px; margin-top: 16px; }
.q-actions .btn { flex: 1; }

/* 结果反馈 */
.feedback { padding: 12px 14px; border-radius: 10px; margin-top: 14px; font-size: 14px; }
.feedback.ok { background: var(--ok-bg); color: #14532d; }
.feedback.bad { background: var(--bad-bg); color: #7f1d1d; }
.feedback .exp { margin-top: 6px; color: #374151; }

/* 错字高亮（听写） */
.dict-view { font-size: 22px; letter-spacing: 3px; line-height: 2; margin: 12px 0; }
.dict-view .ch { padding: 2px 1px; border-radius: 4px; }
.dict-view .ch.ok { color: var(--ok); }
.dict-view .ch.bad { background: #fecaca; color: #991b1b; font-weight: 600; }
.dict-view .ch.miss { background: #fef3c7; color: #92400e; }

/* 徽章 */
.badges { display: flex; flex-wrap: wrap; gap: 8px; }
.badge {
  display: flex; align-items: center; gap: 4px; padding: 6px 11px;
  background: #fffbeb; border: 1px solid #fde68a; border-radius: 999px; font-size: 13px;
}
.badge.locked { opacity: .4; background: #f9fafb; border-color: var(--line); filter: grayscale(1); }

/* 科目网格 */
.subj-grid { display: grid; grid-template-columns: repeat(auto-fit,minmax(120px,1fr)); gap: 10px; }
.subj {
  padding: 14px 10px; border-radius: 12px; background: #fff;
  border: 1.5px solid var(--line); text-align: center;
}
.subj:hover { border-color: var(--primary); }
.subj .ic { font-size: 26px; }
.subj b { display: block; font-size: 15px; }
.subj span { font-size: 12px; color: var(--muted); }

.chapter-list { display: flex; flex-wrap: wrap; gap: 8px; }
.chip {
  padding: 8px 13px; border-radius: 999px; background: #f3f4f6;
  font-size: 13px; color: #374151;
}
.chip:hover { background: var(--primary); color: #fff; }
.chip.on { background: var(--primary); color: #fff; }

/* 表格 */
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { padding: 10px 8px; text-align: left; border-bottom: 1px solid var(--line); }
th { font-size: 12px; color: var(--muted); font-weight: 500; }
tr:last-child td { border-bottom: none; }

/* 徽章标签 */
.tag-pill {
  display: inline-block; padding: 2px 8px; border-radius: 999px;
  font-size: 12px; background: #f1f5f9; color: #475569;
}
.tag-pill.good { background: var(--ok-bg); color: #166534; }
.tag-pill.bad { background: var(--bad-bg); color: #991b1b; }
.tag-pill.warn { background: #fef3c7; color: #92400e; }

/* 弹层 */
.sheet-mask {
  position: fixed; inset: 0; background: rgba(0,0,0,.45);
  display: grid; place-items: center; z-index: 100; padding: 20px;
}
.sheet {
  background: #fff; border-radius: 16px; padding: 24px;
  max-width: 420px; width: 100%; max-height: 85vh; overflow-y: auto;
}

/* toast */
.toast {
  position: fixed; left: 50%; bottom: 40px; transform: translateX(-50%);
  background: #1f2937; color: #fff; padding: 11px 20px; border-radius: 10px;
  font-size: 14px; z-index: 200; box-shadow: 0 8px 24px rgba(0,0,0,.2);
  animation: toastIn .2s;
}
@keyframes toastIn { from { opacity:0; transform:translate(-50%,10px); } }

/* 骨架屏 */
.skeleton { background: linear-gradient(90deg,#f1f5f9 25%,#e2e8f0 50%,#f1f5f9 75%); background-size:200% 100%; animation: sk 1.2s infinite; border-radius: 8px; }
@keyframes sk { to { background-position: -200% 0; } }