/* ============================================================
   flashcard.css —— 速记闪卡样式
   内容：控制栏（模式/科目/操作）、3D 翻转卡片、自评按钮、
        遮盖默写、卡片管理列表、空状态、移动端适配
   ============================================================ */

/* ---------- 顶部控制栏 ---------- */
.fc-toolbar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px;
  margin-bottom: 18px;
}
.fc-modes {
  display: flex; gap: 4px; padding: 4px;
  background: var(--surface-2); border-radius: var(--radius);
  overflow-x: auto;
}
.fc-mode {
  border: none; background: none; color: var(--text-2);
  padding: 8px 14px; border-radius: var(--radius-sm);
  font-size: 14px; white-space: nowrap; cursor: pointer;
  min-height: 40px;
}
.fc-mode.active { background: var(--surface); color: var(--primary); font-weight: 600; box-shadow: var(--shadow); }
.fc-grow { flex: 1; }
.fc-toolbar select { min-height: 40px; }

/* ---------- 学习区 ---------- */
.fc-study { max-width: 720px; margin: 0 auto; }

/* 进度信息 */
.fc-progress {
  display: flex; align-items: center; justify-content: space-between;
  margin-bottom: 12px; font-size: 14px; color: var(--text-2);
}
.fc-pbar {
  height: 6px; background: var(--surface-2); border-radius: 99px;
  overflow: hidden; margin-bottom: 22px;
}
.fc-pbar > i { display: block; height: 100%; background: var(--primary); border-radius: 99px; transition: width .25s ease; }

/* 3D 卡片 */
.fc-scene {
  perspective: 1600px;
  margin-bottom: 22px;
}
.fc-card {
  position: relative; width: 100%;
  min-height: 320px;
  transform-style: preserve-3d;
  transition: transform .5s cubic-bezier(.2,.7,.3,1);
  cursor: pointer;
}
.fc-card.flipped { transform: rotateY(180deg); }

.fc-face {
  position: absolute; inset: 0;
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius-lg); box-shadow: var(--shadow);
  padding: 30px 32px;
  display: flex; flex-direction: column;
  /* 不依赖 backface-visibility（部分浏览器不支持）：在翻转中点交换两面可见性 */
  transition: visibility 0s linear .25s;
}
.fc-face.front { visibility: visible; }
.fc-face.back { transform: rotateY(180deg); visibility: hidden; }
.fc-card.flipped .fc-face.front { visibility: hidden; }
.fc-card.flipped .fc-face.back { visibility: visible; }

/* 卡片头部：科目/章节标签 */
.fc-meta {
  display: flex; flex-wrap: wrap; gap: 6px; align-items: center;
  margin-bottom: 18px;
}
.fc-chip {
  font-size: 12px; color: var(--text-2);
  background: var(--surface-2); border-radius: 99px;
  padding: 3px 10px;
}
.fc-main {
  flex: 1; display: flex; flex-direction: column;
  justify-content: center;
  font-size: 18px; line-height: 1.8; color: var(--text);
  overflow-wrap: break-word;
}
.fc-front-text {
  font-size: 22px; font-weight: 600; line-height: 1.6; text-align: center;
}
.fc-hint {
  margin-top: 18px; text-align: center;
  font-size: 13px; color: var(--text-3);
}

/* 卡片内 Markdown 排版 */
.fc-main p { margin: 0 0 10px; }
.fc-main ul, .fc-main ol { margin: 4px 0 10px; padding-left: 24px; }
.fc-main li { margin: 2px 0; }
.fc-main pre {
  background: var(--surface-2); border-radius: var(--radius-sm);
  padding: 12px 14px; overflow-x: auto; font-size: 14px;
}
.fc-main code { font-family: ui-monospace, Consolas, monospace; font-size: .92em; }
.fc-main table { font-size: 14px; }

/* ---------- 自评按钮（三档） ---------- */
.fc-grades {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px;
  margin-bottom: 14px;
}
.fc-grade {
  border: 1px solid var(--border); background: var(--surface);
  border-radius: var(--radius); padding: 14px 8px;
  font-size: 15px; cursor: pointer; min-height: 52px;
  display: flex; flex-direction: column; align-items: center; gap: 2px;
  transition: transform .12s ease, border-color .12s ease, background .12s ease;
}
.fc-grade small { font-size: 12px; color: var(--text-3); font-weight: 400; }
.fc-grade:active { transform: scale(.97); }
.fc-grade.g-again { color: var(--danger); }
.fc-grade.g-hard { color: var(--warning); }
.fc-grade.g-good { color: var(--success); }
.fc-grade.g-again:hover { border-color: var(--danger); background: color-mix(in srgb, var(--danger) 7%, transparent); }
.fc-grade.g-hard:hover { border-color: var(--warning); background: color-mix(in srgb, var(--warning) 7%, transparent); }
.fc-grade.g-good:hover { border-color: var(--success); background: color-mix(in srgb, var(--success) 7%, transparent); }
/* 翻转前（只看正面）禁用自评，提示先翻面 */
.fc-grades.locked { opacity: .45; pointer-events: none; }

/* 朗读 + 导航 */
.fc-actions {
  display: flex; align-items: center; justify-content: center; gap: 10px;
}
.fc-icon-btn {
  width: 46px; height: 46px; border-radius: 50%;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-2); cursor: pointer;
  display: flex; align-items: center; justify-content: center;
}
.fc-icon-btn:hover { color: var(--primary); border-color: var(--primary); }
.fc-icon-btn .ic { width: 20px; height: 20px; }

/* ---------- 遮盖默写模式 ---------- */
.cloze-blank {
  display: inline-block; min-width: 64px;
  border-bottom: 2px solid var(--accent);
  text-align: center; color: transparent;
  margin: 0 2px;
  user-select: none;
}
.cloze-answer {
  display: none; color: var(--success); font-weight: 600;
  background: color-mix(in srgb, var(--success) 10%, transparent);
  border-radius: 4px; padding: 0 4px;
}
.fc-card.revealed .cloze-blank { display: none; }
.fc-card.revealed .cloze-answer { display: inline; }
.fc-cloze-tip {
  text-align: center; font-size: 13px; color: var(--accent);
  margin-bottom: 14px;
}

/* ---------- 完成总结 ---------- */
.fc-done {
  text-align: center; padding: 50px 20px;
}
.fc-done .big {
  width: 72px; height: 72px; margin: 0 auto 18px;
  border-radius: 50%; background: var(--primary-soft);
  display: flex; align-items: center; justify-content: center;
  color: var(--primary);
}
.fc-done h2 { font-size: 22px; margin-bottom: 8px; }
.fc-done p { color: var(--text-2); margin-bottom: 22px; }
.fc-done .row-btns { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* ---------- 卡片管理（列表） ---------- */
.fc-manage-head {
  display: flex; align-items: center; justify-content: space-between;
  gap: 10px; margin-bottom: 14px; flex-wrap: wrap;
}
.fc-list { display: flex; flex-direction: column; gap: 10px; }
.fc-item {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 14px 16px;
  display: flex; align-items: flex-start; gap: 12px;
}
.fc-item.is-mastered { border-left: 3px solid var(--success); }
.fc-item-body { flex: 1; min-width: 0; }
.fc-item-front { font-weight: 600; font-size: 15px; margin-bottom: 4px; }
.fc-item-back {
  font-size: 13px; color: var(--text-2); line-height: 1.6;
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical;
  overflow: hidden;
}
.fc-item-meta { display: flex; gap: 6px; margin-top: 8px; flex-wrap: wrap; }
.fc-item-ops { display: flex; gap: 4px; }
.fc-item-ops button {
  width: 38px; height: 38px; border: none; background: none;
  color: var(--text-3); border-radius: var(--radius-sm); cursor: pointer;
}
.fc-item-ops button:hover { color: var(--primary); background: var(--surface-2); }

/* ---------- 空状态 ---------- */
.fc-empty {
  text-align: center; padding: 60px 20px;
}
.fc-empty .big {
  width: 80px; height: 80px; margin: 0 auto 18px;
  border-radius: 20px; background: var(--primary-soft);
  display: flex; align-items: center; justify-content: center;
  color: var(--primary);
}
.fc-empty h2 { font-size: 20px; margin-bottom: 8px; }
.fc-empty p { color: var(--text-2); margin-bottom: 22px; font-size: 14.5px; }
.fc-empty .btns { display: flex; gap: 10px; justify-content: center; flex-wrap: wrap; }

/* ---------- 编辑器表单 ---------- */
.fc-form { display: flex; flex-direction: column; gap: 14px; min-width: 320px; }
.fc-form label { font-size: 13px; color: var(--text-2); display: block; margin-bottom: 5px; }
.fc-form textarea { min-height: 110px; resize: vertical; font-family: inherit; }
.fc-form .input, .fc-form select, .fc-form textarea { width: 100%; }

/* ---------- 移动端 ---------- */
@media (max-width: 768px) {
  .fc-face { padding: 20px 18px; }
  .fc-front-text { font-size: 19px; }
  .fc-main { font-size: 16.5px; }
  .fc-card { min-height: 214px; }
  .fc-toolbar { gap: 8px; margin-bottom: 12px; }
  .fc-grow { display: none; }
  .fc-grade { font-size: 14px; padding: 12px 6px; }
  /* 压缩纵向间距，保证三档自评按钮在一屏内、不被底部 Tab 遮挡 */
  .fc-scene { margin-bottom: 12px; }
  .fc-pbar { margin-bottom: 12px; }
  .fc-grades { margin-bottom: 10px; }
  .fc-grade { min-height: 48px; }
}
@media (max-width: 420px) {
  .fc-mode { padding: 8px 11px; font-size: 13px; }
  .fc-grades { gap: 7px; }
}