/* 古诗文背诵学习系统 —— 基础样式
   设计语言参考「英语语法填空练习（English Grammar Lab）」：
   玻璃卡片 + 蓝紫渐变主色 + 深色模式 + 圆角胶囊。 */

/* ============ 主题变量 ============ */

:root {
  --bg1: #f4f7ff;
  --bg2: #eef2ff;
  --bg3: #eae6ff;
  --ink: #101528;
  --ink-dim: #4a5470;
  --ink-faint: #7c86a4;
  --glass: rgba(255, 255, 255, 0.72);
  --glass-strong: rgba(255, 255, 255, 0.9);
  --stroke: rgba(16, 21, 40, 0.1);
  --stroke-strong: rgba(16, 21, 40, 0.16);
  --accent: #4a6cf7;
  --accent2: #7c5cff;
  --accent-ink: #3550c8;
  --accent-bg: rgba(74, 108, 247, 0.12);
  --ok: #0f9d63;
  --ok-bg: rgba(15, 157, 99, 0.12);
  --bad: #e11d48;
  --bad-bg: rgba(225, 29, 72, 0.12);
  --warn: #a15c07;
  --warn-bg: rgba(245, 158, 11, 0.16);
  --glow: #b06a00;
  --radius: 18px;
  --radius-sm: 12px;
  --radius-xs: 9px;
  --shadow: 0 18px 44px rgba(24, 32, 72, 0.12);
  --shadow-sm: 0 6px 18px rgba(24, 32, 72, 0.08);
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --topbar: rgba(247, 249, 255, 0.82);
  --tap-min: 2.75rem;
  --font-serif: "Songti SC", "SimSun", "Noto Serif SC", "Source Han Serif SC", serif;
  color-scheme: light;

  /* 兼容旧变量名（组件层继续复用） */
  --bg-main: var(--bg1);
  --bg-soft: rgba(16, 21, 40, 0.05);
  --text-main: var(--ink);
  --text-dark: var(--ink);
  --text-muted: var(--ink-dim);
  --text-faint: var(--ink-faint);
  --text-info: var(--ink-dim);
  --primary: var(--accent);
  --primary-hover: var(--accent-ink);
  --primary-bg: var(--accent-bg);
  --primary-border: rgba(74, 108, 247, 0.32);
  --success: var(--ok);
  --success-hover: var(--ok);
  --success-bg: var(--ok-bg);
  --danger: var(--bad);
  --danger-bg: var(--bad-bg);
  --card-bg: var(--glass);
  --border-color: var(--stroke);
  --border-soft: var(--stroke);
  --radius-lg: var(--radius);
  --radius-md: var(--radius-sm);
  --shadow-md: var(--shadow);
}

html[data-theme='dark'] {
  --bg1: #0b1020;
  --bg2: #141a33;
  --bg3: #1d2450;
  --ink: #eef1fb;
  --ink-dim: #b8c2e0;
  --ink-faint: #8e9abf;
  --glass: rgba(255, 255, 255, 0.055);
  --glass-strong: rgba(255, 255, 255, 0.09);
  --stroke: rgba(255, 255, 255, 0.13);
  --stroke-strong: rgba(255, 255, 255, 0.2);
  --accent: #5b8cff;
  --accent2: #7c6bff;
  --accent-ink: #a8c0ff;
  --accent-bg: rgba(91, 140, 255, 0.16);
  --ok: #3ecf8e;
  --ok-bg: rgba(62, 207, 142, 0.14);
  --bad: #ff5d7a;
  --bad-bg: rgba(255, 93, 122, 0.14);
  --warn: #ffb84d;
  --warn-bg: rgba(255, 184, 77, 0.14);
  --glow: #ffe082;
  --shadow: 0 18px 50px rgba(0, 0, 0, 0.42);
  --shadow-sm: 0 8px 22px rgba(0, 0, 0, 0.32);
  --topbar: rgba(10, 14, 30, 0.72);
  --bg-soft: rgba(255, 255, 255, 0.06);
  --primary-border: rgba(91, 140, 255, 0.42);
  color-scheme: dark;
}

* { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  background-color: var(--bg1);
  color-scheme: light;
}
html[data-theme='dark'] { color-scheme: dark; }

body {
  margin: 0;
  color: var(--ink);
  font-family: "PingFang SC", "HarmonyOS Sans SC", "Microsoft YaHei", "Segoe UI", system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  min-height: 100vh;
  min-height: 100dvh;
  overflow-x: hidden;
  background: transparent;
}

/* 背景光晕层：单独铺满可视区，滚动时不会露出白边 */
body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(1100px 620px at 85% -10%, color-mix(in srgb, var(--accent) 22%, transparent), transparent 60%),
    radial-gradient(900px 560px at -10% 110%, color-mix(in srgb, var(--accent2) 20%, transparent), transparent 55%),
    linear-gradient(160deg, var(--bg1) 0%, var(--bg2) 55%, var(--bg3) 100%);
}

button, input, select { font-family: inherit; }

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  background: var(--glass-strong);
  padding: 0.5rem 1rem;
  border-radius: var(--radius-sm);
  z-index: 90;
}
.skip-link:focus { left: 0.5rem; top: 0.5rem; }

.app {
  max-width: 68rem;
  margin: 0 auto;
  padding: 0 0.9rem 3rem;
}

/* ============ 顶栏 ============ */

.app-header {
  position: sticky;
  top: 0;
  z-index: 40;
  margin: 0 -0.9rem 1rem;
  padding: 0.55rem 0.9rem;
  background: var(--topbar);
  backdrop-filter: blur(18px) saturate(1.2);
  -webkit-backdrop-filter: blur(18px) saturate(1.2);
  border-bottom: 1px solid var(--stroke);
}

.app-header-inner {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  max-width: 68rem;
  margin: 0 auto;
}

.header-back {
  flex: none;
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 12px;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  color: var(--ink-dim);
  font-size: 1.05rem;
  line-height: 1;
  cursor: pointer;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.15s var(--ease);
}
.header-back:hover { color: var(--accent); border-color: var(--primary-border); }
.header-back:active { transform: scale(0.95); }

.brand-lockup {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  min-width: 0;
  flex: 1;
}

.brand-logo {
  flex: none;
  width: 2.1rem;
  height: 2.1rem;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 1.05rem;
  font-weight: 800;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 6px 16px color-mix(in srgb, var(--accent) 40%, transparent);
}

.app-title-box {
  min-width: 0;
  max-width: 34rem;
  overflow: hidden;
  opacity: 1;
  transition: max-width 0.3s var(--ease), opacity 0.24s var(--ease);
}

.app-title {
  margin: 0;
  font-size: 1.0625rem;
  font-weight: 800;
  letter-spacing: 0.01em;
  color: var(--ink);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.app-subtitle {
  margin: 0;
  font-size: 0.6875rem;
  color: var(--ink-faint);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-actions {
  flex: none;
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.header-meta {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.75rem;
  color: var(--ink-dim);
}

.icon-btn {
  width: 2.4rem;
  height: 2.4rem;
  border-radius: 12px;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  color: var(--ink-dim);
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.15s var(--ease);
}
.icon-btn:hover { color: var(--accent); border-color: var(--primary-border); }
.icon-btn:active { transform: scale(0.95); }

@media (max-width: 560px) {
  /* 窄屏（含竖屏手机）：标题与小标题一起收起，只留左上角图标 */
  .brand-lockup { gap: 0; }
  .brand-lockup .app-title-box { max-width: 0; opacity: 0; }
}

/* 竖屏（手机 / 平板）：同样只留图标，旋转屏幕时带动画收起 / 展开 */
@media (max-width: 900px) and (orientation: portrait) {
  .brand-lockup { gap: 0; }
  .brand-lockup .app-title-box { max-width: 0; opacity: 0; }
}

/* ============ 卡片与通用排版 ============ */

.card {
  background: var(--glass);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  backdrop-filter: blur(16px) saturate(1.2);
  -webkit-backdrop-filter: blur(16px) saturate(1.2);
  box-shadow: var(--shadow-sm);
  padding: 1.05rem;
}

.card + .card, .card + .feature-grid, .feature-grid + .card { margin-top: 0.9rem; }

.section-title {
  margin: 0 0 0.25rem;
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.2px;
  color: var(--ink);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.section-title .ico { font-size: 1.15rem; }

.section-desc {
  margin: 0;
  font-size: 0.8125rem;
  color: var(--ink-dim);
}

.muted { color: var(--ink-dim); }
.tiny { font-size: 0.75rem; }

.badge {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  padding: 0.1rem 0.5rem;
  border-radius: 999px;
  font-size: 0.6875rem;
  font-weight: 700;
  background: var(--glass-strong);
  color: var(--ink-dim);
  border: 1px solid var(--stroke);
  white-space: nowrap;
}
.badge-primary { background: var(--accent-bg); color: var(--accent-ink); border-color: var(--primary-border); }
.badge-success { background: var(--ok-bg); color: var(--ok); border-color: color-mix(in srgb, var(--ok) 34%, transparent); }
.badge-warn { background: var(--warn-bg); color: var(--warn); border-color: color-mix(in srgb, var(--warn) 34%, transparent); }
.badge-danger { background: var(--bad-bg); color: var(--bad); border-color: color-mix(in srgb, var(--bad) 34%, transparent); }

/* ============ 按钮 ============ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  min-height: var(--tap-min);
  padding: 0.5rem 1rem;
  border-radius: 14px;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  color: var(--ink);
  font-size: 0.875rem;
  font-weight: 700;
  cursor: pointer;
  transition: transform 0.15s var(--ease), filter 0.18s var(--ease), box-shadow 0.2s var(--ease), border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.btn:hover { border-color: var(--primary-border); color: var(--accent); }
.btn:active { transform: scale(0.96); }
.btn[disabled] { opacity: 0.5; cursor: not-allowed; }
.btn[disabled]:active { transform: none; }

.btn-primary {
  border-color: transparent;
  color: #fff;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  box-shadow: 0 10px 24px color-mix(in srgb, var(--accent) 32%, transparent);
}
.btn-primary:hover { color: #fff; filter: brightness(1.06); }

.btn-success {
  border-color: transparent;
  color: #052; /* 深色文字保证浅色底可读，暗色主题下由滤镜修正 */
  background: linear-gradient(135deg, color-mix(in srgb, var(--ok) 82%, #fff), var(--ok));
  box-shadow: 0 10px 24px color-mix(in srgb, var(--ok) 28%, transparent);
}
html[data-theme='dark'] .btn-success { color: #06231a; }
.btn-success:hover { filter: brightness(1.05); }

.btn-sm { min-height: 2.3rem; padding: 0.3rem 0.75rem; font-size: 0.8125rem; border-radius: 12px; }

.btn:focus-visible,
.chip:focus-visible,
.poem-card:focus-visible,
.line-item:focus-visible,
.hint-item:focus-visible,
.stage-card:focus-visible,
.feature-card:focus-visible,
.icon-btn:focus-visible,
.header-back:focus-visible,
.brand-seal:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

/* ============ 胶囊标签（筛选 / 选项） ============ */

.chips { display: flex; flex-wrap: wrap; gap: 0.375rem; }

.chip {
  border: 1px solid var(--stroke);
  background: var(--glass);
  color: var(--ink-dim);
  padding: 0.35rem 0.75rem;
  border-radius: 999px;
  font-size: 0.8125rem;
  font-weight: 600;
  cursor: pointer;
  min-height: 2.25rem;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background 0.18s var(--ease);
}
.chip:hover { border-color: var(--primary-border); color: var(--accent); }
.chip.active {
  background: var(--accent-bg);
  border-color: var(--primary-border);
  color: var(--accent-ink);
}

/* ============ 表单 ============ */

.toolbar { display: grid; gap: 0.7rem; }

.search-box {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: 14px;
  padding: 0 0.75rem;
}
.search-box input {
  flex: 1;
  min-width: 0;
  border: none;
  outline: none;
  font-size: 0.9375rem;
  padding: 0.7rem 0;
  background: transparent;
  color: var(--ink);
}
.search-box input::placeholder { color: var(--ink-faint); }
.search-box .search-clear {
  border: none;
  background: none;
  color: var(--ink-faint);
  cursor: pointer;
  font-size: 1rem;
  padding: 0.5rem;
}

.filter-group { display: grid; gap: 0.4rem; }
.filter-label { font-size: 0.75rem; font-weight: 700; color: var(--ink-faint); }

select {
  width: 100%;
  min-height: var(--tap-min);
  border-radius: 14px;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  padding: 0.5rem 0.7rem;
  font-size: 0.9375rem;
  color: var(--ink);
}

.empty-state {
  text-align: center;
  padding: 2.25rem 1rem;
  color: var(--ink-dim);
  font-size: 0.875rem;
}

/* ============ 首页 Hero ============ */

.hero { position: relative; overflow: hidden; }
.hero::after {
  content: "";
  position: absolute;
  right: -60px;
  top: -80px;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent2) 34%, transparent), transparent 70%);
  pointer-events: none;
}
.hero-kicker {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--ink-faint);
  margin: 0 0 0.35rem;
}
.hero-title {
  margin: 0;
  font-size: 1.5rem;
  line-height: 1.35;
  font-weight: 800;
  letter-spacing: 0.3px;
  color: var(--ink);
}
.hero-title .accent {
  background: linear-gradient(120deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  margin: 0.4rem 0 0;
  font-size: 0.875rem;
  color: var(--ink-dim);
  max-width: 44rem;
}
/* 作者品牌小标签（由 brand.js 注入，视图重渲染后自动补回） */
.brand-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin-top: 0.85rem;
  padding: 0.3rem 0.7rem;
  border-radius: 999px;
  border: 1px dashed var(--stroke-strong);
  background: var(--glass-strong);
  color: var(--ink-dim);
  font-size: 0.75rem;
  cursor: pointer;
  max-width: 100%;
  flex-wrap: wrap;
}
.brand-chip:hover { color: var(--accent); border-color: var(--primary-border); }
.brand-chip .dot { color: var(--ink-faint); }

/* ============ 学段选择 ============ */

.stage-grid {
  display: grid;
  gap: 0.9rem;
  grid-template-columns: 1fr;
  margin-top: 0.9rem;
}
@media (min-width: 640px) { .stage-grid { grid-template-columns: 1fr 1fr; } }

.stage-card {
  position: relative;
  text-align: left;
  cursor: pointer;
  padding: 1.2rem;
  border-radius: var(--radius);
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
  min-height: 8.5rem;
  overflow: hidden;
}
.stage-card::after {
  content: "";
  position: absolute;
  inset: auto -30% -60% auto;
  width: 180px;
  height: 180px;
  border-radius: 50%;
  background: radial-gradient(circle, color-mix(in srgb, var(--accent) 22%, transparent), transparent 70%);
  pointer-events: none;
}
.stage-card:hover { border-color: var(--primary-border); box-shadow: var(--shadow); transform: translateY(-2px); }
.stage-card:active { transform: translateY(0); }
.stage-card .sc-ico { font-size: 1.6rem; }
.stage-card h3 { margin: 0.35rem 0 0.15rem; font-size: 1.35rem; color: var(--ink); }
.stage-card p { margin: 0; font-size: 0.8125rem; color: var(--ink-dim); }
.stage-card .stage-stat { margin-top: 0.75rem; }
.stage-card .sc-go {
  margin-top: 0.7rem;
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--accent);
}

/* ============ 篇目选择 ============ */

.select-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
}
.select-summary { margin-left: auto; font-size: 0.8125rem; font-weight: 700; color: var(--accent-ink); }

.selected-panel { margin-top: 0.25rem; }
.selected-panel summary {
  cursor: pointer;
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--ink-dim);
  min-height: 2.25rem;
  display: flex;
  align-items: center;
}
.selected-list { display: flex; flex-wrap: wrap; gap: 0.375rem; margin-top: 0.5rem; }
.selected-chip {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: 999px;
  padding: 0.25rem 0.5rem 0.25rem 0.7rem;
  font-size: 0.8125rem;
}
.selected-chip button {
  border: none;
  background: none;
  color: var(--ink-faint);
  cursor: pointer;
  font-size: 1rem;
  line-height: 1;
  padding: 0.2rem 0.3rem;
}
.selected-chip button:hover { color: var(--bad); }

.group-block { margin-top: 1.15rem; }
.group-heading {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  font-weight: 800;
  color: var(--ink-dim);
  border-bottom: 1px solid var(--stroke);
  padding-bottom: 0.35rem;
  margin-bottom: 0.6rem;
}
.group-heading .group-line { flex: 1; height: 1px; background: var(--stroke); }

.poem-grid { display: grid; gap: 0.5rem; grid-template-columns: 1fr; }
@media (min-width: 640px) { .poem-grid { grid-template-columns: 1fr 1fr; } }

.poem-card {
  display: flex;
  align-items: flex-start;
  gap: 0.6rem;
  text-align: left;
  padding: 0.7rem 0.8rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--stroke);
  background: var(--glass);
  cursor: pointer;
  min-height: var(--tap-min);
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease), transform 0.15s var(--ease);
}
.poem-card:hover { border-color: var(--primary-border); transform: translateY(-1px); }
.poem-card.checked { background: var(--accent-bg); border-color: var(--primary-border); }
.poem-card .check {
  flex: none;
  width: 1.15rem;
  height: 1.15rem;
  margin-top: 0.2rem;
  border-radius: 0.35rem;
  border: 1.5px solid var(--stroke-strong);
  background: transparent;
  display: grid;
  place-items: center;
  font-size: 0.75rem;
  color: #fff;
}
.poem-card.checked .check {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border-color: transparent;
}
.poem-card .poem-main { min-width: 0; flex: 1; }
.poem-card .poem-title { font-weight: 700; color: var(--ink); font-size: 0.9375rem; display: block; }
.poem-card .poem-sub { font-size: 0.75rem; color: var(--ink-dim); margin-top: 0.1rem; display: block; }
.poem-card .poem-tags { display: flex; flex-wrap: wrap; gap: 0.25rem; margin-top: 0.35rem; }

/* ============ 工作台 ============ */

.stat-row {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(7.5rem, 1fr));
  gap: 0.6rem;
  margin-top: 0.85rem;
}
.stat-box {
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  padding: 0.7rem 0.8rem;
}
.stat-box .stat-num { font-size: 1.35rem; font-weight: 800; color: var(--ink); line-height: 1.3; }
.stat-box .stat-label { font-size: 0.6875rem; color: var(--ink-faint); }

.bar {
  height: 0.5rem;
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: 999px;
  overflow: hidden;
  margin-top: 0.6rem;
}
.bar > span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  border-radius: 999px;
  transition: width 0.35s var(--ease);
}

.feature-grid { display: grid; gap: 0.7rem; grid-template-columns: 1fr; margin-top: 0.9rem; }
@media (min-width: 640px) { .feature-grid { grid-template-columns: 1fr 1fr; } }

.feature-card {
  text-align: left;
  cursor: pointer;
  padding: 1.1rem 1rem;
  border-radius: var(--radius);
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  box-shadow: var(--shadow-sm);
  min-height: 5.4rem;
  transition: transform 0.2s var(--ease), border-color 0.2s var(--ease), box-shadow 0.2s var(--ease);
}
.feature-card:hover { border-color: var(--primary-border); box-shadow: var(--shadow); transform: translateY(-2px); }
.feature-card:active { transform: translateY(0); }
.feature-card .fc-ico {
  width: 2.3rem;
  height: 2.3rem;
  border-radius: 12px;
  display: grid;
  place-items: center;
  font-size: 1.15rem;
  background: var(--accent-bg);
  border: 1px solid var(--primary-border);
  margin-bottom: 0.5rem;
}
.feature-card h3 { margin: 0 0 0.15rem; font-size: 1rem; color: var(--ink); }
.feature-card p { margin: 0; font-size: 0.8125rem; color: var(--ink-dim); }

/* ============ 全文学习 ============ */

.study-toolbar { display: flex; flex-wrap: wrap; gap: 0.5rem; align-items: center; }

.poem-switch { margin-bottom: 0.75rem; }

.poem-head { border-bottom: 1px dashed var(--stroke); padding-bottom: 0.75rem; margin-bottom: 0.75rem; }
.poem-head h2 { margin: 0; font-size: 1.3rem; color: var(--ink); }
.poem-head .poem-byline { font-size: 0.8125rem; color: var(--ink-dim); margin-top: 0.2rem; }
.poem-head .poem-tags { display: flex; flex-wrap: wrap; gap: 0.25rem; margin-top: 0.5rem; }

.poem-body {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 2;
  color: var(--ink);
}

.line-item {
  display: block;
  width: 100%;
  text-align: left;
  border: 1px solid transparent;
  background: transparent;
  border-radius: var(--radius-xs);
  padding: 0.35rem 0.5rem;
  margin: 0 -0.5rem;
  font: inherit;
  color: inherit;
  cursor: pointer;
  transition: background 0.18s var(--ease), color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.line-item:hover { background: var(--glass-strong); }
.line-item.is-hidden .line-text { color: var(--ink-faint); letter-spacing: 0.08em; }
.line-item.is-active { background: var(--accent-bg); border-color: var(--primary-border); }
.hint-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  justify-content: space-between;
  margin-top: 0.75rem;
}

.poem-meta-block { margin-top: 1rem; font-size: 0.8125rem; color: var(--ink-dim); }
.poem-meta-block dt { font-weight: 700; color: var(--ink-faint); margin-top: 0.5rem; }
.poem-meta-block dd { margin: 0.15rem 0 0; }

.hint-list { display: grid; gap: 0.3rem; margin-top: 0.35rem; }
.hint-item {
  text-align: left;
  font-size: 0.8125rem;
  color: var(--ink-dim);
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-xs);
  padding: 0.4rem 0.55rem;
  cursor: pointer;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}
.hint-item:hover { color: var(--accent); border-color: var(--primary-border); }

/* ============ 默写自测 ============ */

.quiz-settings { display: grid; gap: 0.75rem; }
.quiz-mode-list { display: grid; gap: 0.4rem; }
.mode-option {
  display: flex;
  gap: 0.5rem;
  align-items: flex-start;
  font-size: 0.875rem;
  cursor: pointer;
  padding: 0.5rem 0.55rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--stroke);
  background: var(--glass);
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}
.mode-option:hover { border-color: var(--primary-border); }
.mode-option input { margin-top: 0.28rem; accent-color: var(--accent); width: 1rem; height: 1rem; }
.mode-option .mode-desc { display: block; font-size: 0.75rem; color: var(--ink-dim); font-weight: 400; }
.mode-option:has(input:checked) { background: var(--accent-bg); border-color: var(--primary-border); }

.quiz-card {
  background: var(--glass);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  backdrop-filter: blur(14px) saturate(1.15);
  -webkit-backdrop-filter: blur(14px) saturate(1.15);
  box-shadow: var(--shadow-sm);
  padding: 1rem;
}
.quiz-card + .quiz-card { margin-top: 0.75rem; }

.card-header { display: flex; align-items: flex-start; gap: 0.75rem; }
.card-meta {
  font-size: 0.75rem;
  color: var(--ink-faint);
  font-weight: 600;
  display: flex;
  flex-wrap: wrap;
  gap: 0.35rem;
  align-items: center;
}

.question-text {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.9;
  color: var(--ink);
  margin-top: 0.35rem;
  word-break: break-word;
}
.question-text .blank-unit { color: var(--accent); letter-spacing: 0.1em; }
.question-text .context-hint { color: var(--ink-faint); }

.btn-eye {
  flex: none;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  color: var(--ink-dim);
  border-radius: 12px;
  width: 2.5rem;
  height: 2.5rem;
  display: grid;
  place-items: center;
  cursor: pointer;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.15s var(--ease);
}
.btn-eye:hover { color: var(--accent); border-color: var(--primary-border); }
.btn-eye:active { transform: scale(0.95); }
.btn-eye svg { width: 1.25rem; height: 1.25rem; fill: none; stroke: currentColor; stroke-width: 2; stroke-linecap: round; stroke-linejoin: round; }
.btn-eye .hidden { display: none; }

/* 沿用原项目的答案展开动画：grid-template-rows 0fr -> 1fr */
.answer-wrapper {
  display: grid;
  grid-template-rows: 0fr;
  transition: grid-template-rows 0.22s var(--ease), opacity 0.18s ease;
  opacity: 0;
}
.answer-wrapper.show { grid-template-rows: 1fr; opacity: 1; margin-top: 0.6rem; }
.answer-content { overflow: hidden; }
.answer-inner {
  padding-top: 0.7rem;
  border-top: 1px dashed var(--stroke);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.9;
}
.answer-badge-text {
  color: var(--ok);
  font-weight: 700;
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  align-items: baseline;
}
.answer-badge-text .answer-text { color: var(--ink); font-weight: 700; }

.grade-row { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 0.7rem; }

/* ============ 我的进度 ============ */

.progress-list { display: grid; gap: 0.5rem; margin-top: 0.75rem; }
.progress-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.65rem 0.75rem;
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
}
.progress-item .pi-main { min-width: 0; }
.progress-item .pi-sub { font-size: 0.75rem; color: var(--ink-dim); }

.danger-zone { margin-top: 1.25rem; border-top: 1px solid var(--stroke); padding-top: 0.75rem; }

/* ============ 提示条 ============ */

.toast {
  position: fixed;
  left: 50%;
  bottom: 1.5rem;
  transform: translate(-50%, 1rem);
  background: var(--glass-strong);
  color: var(--ink);
  border: 1px solid var(--stroke);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  padding: 0.6rem 1.05rem;
  border-radius: 999px;
  font-size: 0.8125rem;
  max-width: min(90vw, 26rem);
  text-align: center;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s var(--ease), transform 0.2s var(--ease);
  z-index: 60;
}
.toast.show { opacity: 1; transform: translate(-50%, 0); }

@media (max-width: 560px) {
  .toast { bottom: 4.6rem; }   /* 避开右下角作者印章 */
}

/* ============ 动画 ============ */

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: none; }
}
.view-inner { animation: fadeUp 0.28s var(--ease); }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

/* ============ 适配 ============ */

@media (max-width: 420px) {
  body { font-size: 15px; }
  .app-title { font-size: 1rem; }
  .app-header { padding: 0.5rem 0.75rem; }
  .hero-title { font-size: 1.3rem; }
  .poem-body { font-size: 1rem; line-height: 1.95; }
  .brand-logo { width: 1.9rem; height: 1.9rem; border-radius: 10px; font-size: 0.95rem; }
}

@media (max-width: 540px) {
  .quiz-mode-list { grid-template-columns: 1fr 1fr; display: grid; gap: 0.35rem; }
  .mode-option { align-items: center; padding: 0.42rem 0.45rem; font-size: 0.8125rem; }
  .mode-option input { margin-top: 0; }
  .mode-option .mode-desc { display: none; }
  .stat-row { grid-template-columns: 1fr 1fr; }
}

@media (min-width: 900px) {
  .feature-grid { grid-template-columns: repeat(4, 1fr); }
}

@media print {
  .app-header, .app-footer, .btn, .btn-eye, .study-toolbar, .brand-seal { display: none !important; }
  .answer-wrapper { grid-template-rows: 1fr; opacity: 1; }
  body::before { display: none; }
}

/* ============ 品牌层（署名 / 印章 / 页脚 / 授权弹窗） ============ */
/* __BRAND_CSS__ */

.brand-foot {
  margin-top: 2rem;
  padding: 1.1rem 0.2rem 0.2rem;
  border-top: 1px solid var(--stroke);
  text-align: center;
  font-size: 0.75rem;
  color: var(--ink-faint);
  line-height: 1.75;
}
.brand-foot .bf-main { font-weight: 700; color: var(--ink-dim); }
.brand-foot .bf-brand { margin-top: 0.25rem; }
.brand-foot .bf-brand b { color: var(--ink-dim); }
.brand-foot .bf-links {
  margin-top: 0.5rem;
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
  align-items: center;
  justify-content: center;
}
.brand-foot .bf-ver { margin-top: 0.45rem; color: var(--ink-faint); }
/* 版本号下方的 GitHub 开源仓库链接 */
.brand-foot .bf-repo { margin-top: 0.3rem; font-size: 0.6875rem; color: var(--ink-faint); }
.brand-foot .bf-repo a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}
.brand-foot .bf-repo a:hover { border-bottom-color: currentColor; }
.brand-foot .bf-repo a:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; border-radius: 4px; }
.brand-foot .bf-links .tip {
  border: 1px dashed var(--stroke-strong);
  border-radius: 999px;
  padding: 0.1rem 0.5rem;
  color: var(--ink-faint);
}
.bf-notes {
  max-width: 36rem;
  margin: 0.5rem auto 0;
  font-size: 0.6875rem;
  line-height: 1.7;
}

/* 右下角署名水印：平时是一枚小胶囊，鼠标悬停 / 点击后【原地】展开成署名卡片（无图标、无弹窗） */
.brand-seal {
  position: fixed;
  right: max(0.75rem, env(safe-area-inset-right));
  bottom: max(0.75rem, env(safe-area-inset-bottom));
  z-index: 55;
  display: block;
  text-align: left;
  overflow: hidden;
  padding: 0.35rem 0.75rem;
  border-radius: 13px;
  border: 1px solid var(--stroke);
  background: var(--glass-strong);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  box-shadow: var(--shadow-sm);
  color: var(--ink-dim);
  font-family: inherit;
  cursor: pointer;
  opacity: 0.9;
  transform-origin: 100% 100%;
  transition: padding 0.34s var(--ease), border-radius 0.34s var(--ease), background 0.3s,
    box-shadow 0.34s var(--ease), opacity 0.24s var(--ease), transform 0.34s var(--ease);
}
.brand-seal .bs-face {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  white-space: nowrap;
  font-size: 0.6875rem;
  font-weight: 700;
  letter-spacing: 0.03em;
}
.brand-seal .bs-panel {
  display: block;
  width: 0;
  max-height: 0;
  opacity: 0;
  margin-top: 0;
  overflow: hidden;
  white-space: nowrap;
  transform: translateY(6px);
  transition: width 0.34s var(--ease), max-height 0.34s var(--ease), opacity 0.26s ease,
    transform 0.34s var(--ease), margin-top 0.34s var(--ease);
}
.brand-seal .bs-name { display: block; font-size: 0.8125rem; font-weight: 800; letter-spacing: 0.02em; color: var(--ink); }
.brand-seal .bs-row { display: block; margin-top: 0.25rem; font-size: 0.75rem; color: var(--ink-dim); }
.brand-seal .bs-row i { font-style: normal; margin-right: 0.45rem; color: var(--ink-faint); }
.brand-seal .bs-row b { color: var(--accent); font-weight: 800; letter-spacing: 0.02em; }
.brand-seal .bs-row:hover b { text-decoration: underline; }
.brand-seal .bs-tip { display: block; margin-top: 0.5rem; font-size: 0.625rem; color: var(--ink-faint); }

/* 展开态：键盘聚焦 / 触摸点击 */
.brand-seal:focus-visible,
.brand-seal.on {
  padding: 0.8rem 0.95rem 0.85rem;
  border-radius: 18px;
  box-shadow: var(--shadow);
  opacity: 1;
  transform: translateY(-2px);
}
.brand-seal:focus-visible .bs-panel,
.brand-seal.on .bs-panel { width: 11rem; max-height: 9rem; opacity: 1; transform: none; margin-top: 0.5rem; }

/* 有鼠标的设备：鼠标移上去即原展开（和点击展开同一套动画） */
@media (hover: hover) {
  .brand-seal:hover {
    padding: 0.8rem 0.95rem 0.85rem;
    border-radius: 18px;
    box-shadow: var(--shadow);
    opacity: 1;
    transform: translateY(-2px);
  }
  .brand-seal:hover .bs-panel { width: 11rem; max-height: 9rem; opacity: 1; transform: none; margin-top: 0.5rem; }
}

/* 授权说明弹窗 */
.brand-overlay {
  position: fixed;
  inset: 0;
  z-index: 80;
  background: rgba(6, 10, 24, 0.55);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  display: grid;
  place-items: center;
  padding: 1rem;
  animation: fadeUp 0.22s var(--ease);
}
.brand-sheet {
  width: min(36rem, 100%);
  max-height: 86vh;
  overflow: auto;
  background: var(--glass-strong);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  backdrop-filter: blur(20px) saturate(1.2);
  -webkit-backdrop-filter: blur(20px) saturate(1.2);
  padding: 1.15rem;
}
.brand-sheet h3 { margin: 0 0 0.2rem; font-size: 1.05rem; color: var(--ink); }
.brand-sheet .bs-sub { margin: 0 0 0.7rem; font-size: 0.75rem; color: var(--ink-faint); }
.brand-sheet .bs-lic { display: grid; gap: 0.45rem; font-size: 0.8125rem; color: var(--ink-dim); }
.brand-sheet .bs-lic b { color: var(--ink); }
.brand-sheet .bs-actions { display: flex; flex-wrap: wrap; gap: 0.5rem; margin-top: 1rem; }