/* =====================================================================
   电子书资源中心 —— 设计系统
   暗色工业风（默认） / 浅色模式；主色品牌红 #D50030；移动优先。
   ===================================================================== */
:root {
  --bg: #0E1116;
  --bg-elev: #161B22;
  --bg-elev2: #1C232C;
  --border: #2A323D;
  --text: #E6EDF3;
  --text-dim: #8B97A5;
  --text-faint: #5B6675;
  --brand: #D50030;
  --brand-soft: rgba(213, 0, 48, 0.14);
  --blue: #539BF5;
  --green: #57AB5A;
  --orange: #E0744B;
  --purple: #B083F0;
  --amber: #E6B422;
  --red: #E5534B;
  --shadow: 0 8px 28px rgba(0, 0, 0, 0.45);
  --radius: 14px;
  --header-h: 64px;
  /* 底部工具栏占据的条带高度：阅读区从 body 底部上抬这么多，
     正文永远滚不到工具栏下面（根治"工具栏挡住文字"）。 */
  --reader-ctl-space: calc(80px + env(safe-area-inset-bottom, 0px));
}
[data-theme="light"] {
  --bg: #F6F8FA;
  --bg-elev: #FFFFFF;
  --bg-elev2: #EEF1F4;
  --border: #E1E6EB;
  --text: #1A2129;
  --text-dim: #5A6675;
  --text-faint: #8A95A3;
  --brand-soft: rgba(213, 0, 48, 0.10);
  --shadow: 0 8px 24px rgba(20, 30, 45, 0.10);
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei",
               "PingFang SC", "Hiragino Sans GB", sans-serif;
  -webkit-font-smoothing: antialiased;
  min-height: 100vh;
  transition: background .25s ease, color .25s ease;
}
a { color: inherit; text-decoration: none; }
button { font-family: inherit; cursor: pointer; }

/* ---------------- Header ---------------- */
.app-header {
  position: sticky; top: 0; z-index: 50;
  height: var(--header-h);
  display: flex; align-items: center; gap: 14px;
  padding: 0 18px;
  background: color-mix(in srgb, var(--bg-elev) 82%, transparent);
  backdrop-filter: blur(14px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 10px; flex: none; }
.brand-mark {
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--brand), #8a0020);
  display: grid; place-items: center;
  font-weight: 800; color: #fff; font-size: 18px;
  box-shadow: 0 4px 14px var(--brand-soft);
}
.brand-name { font-weight: 700; font-size: 16px; letter-spacing: .3px; }
.brand-name small { display: block; font-size: 10px; color: var(--text-faint); font-weight: 500; letter-spacing: 1px; }

.search-box {
  flex: 1; max-width: 560px; margin: 0 auto;
  position: relative; display: flex; align-items: center;
}
.search-box input {
  width: 100%; height: 40px; border-radius: 20px;
  border: 1px solid var(--border); background: var(--bg-elev2);
  color: var(--text); padding: 0 42px 0 16px; font-size: 14px;
  outline: none; transition: border-color .2s, box-shadow .2s;
}
.search-box input:focus { border-color: var(--brand); box-shadow: 0 0 0 3px var(--brand-soft); }
.search-box .clear {
  position: absolute; right: 12px; border: none; background: none;
  color: var(--text-faint); font-size: 18px; line-height: 1; padding: 4px;
}
.icon-btn {
  width: 40px; height: 40px; flex: none; border-radius: 10px;
  border: 1px solid var(--border); background: var(--bg-elev2);
  color: var(--text); display: grid; place-items: center; font-size: 18px;
  transition: background .2s, border-color .2s;
}
.icon-btn:hover { border-color: var(--brand); color: var(--brand); }

/* ---------------- Tabs / filters ---------------- */
.toolbar {
  display: flex; align-items: center; gap: 10px; flex-wrap: wrap;
  padding: 14px 18px 4px;
}
.chip {
  height: 32px; padding: 0 14px; border-radius: 16px;
  border: 1px solid var(--border); background: var(--bg-elev);
  color: var(--text-dim); font-size: 13px; transition: all .18s;
}
.chip:hover { color: var(--text); border-color: var(--text-faint); }
.chip.active { background: var(--brand); border-color: var(--brand); color: #fff; font-weight: 600; }
.spacer { flex: 1; }
.count-label { color: var(--text-faint); font-size: 13px; }

/* ---------------- Book grid ---------------- */
.book-grid {
  display: grid; gap: 18px;
  grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
  padding: 16px 18px 12px;
}
.grid-more {
  display: flex; align-items: center; justify-content: center; gap: 14px;
  padding: 10px 0 46px; flex-wrap: wrap;
}
.grid-more .btn { height: 36px; padding: 0 26px; border-radius: 18px; }
.grid-more .btn-ghost { background: var(--bg-elev); color: var(--text); }
.book-card {
  background: var(--bg-elev); border: 1px solid var(--border);
  border-radius: var(--radius); overflow: hidden; cursor: pointer;
  display: flex; flex-direction: column; position: relative;
  transition: transform .18s ease, border-color .18s, box-shadow .18s;
}
.book-card:hover { transform: translateY(-4px); border-color: var(--brand); box-shadow: var(--shadow); }

/* 卡片右上角「移除」按钮：悬停才出现，点击不触发进入阅读器 */
.book-del {
  position: absolute; top: 6px; right: 6px; z-index: 3;
  width: 28px; height: 28px; border-radius: 8px;
  border: 1px solid var(--border); background: rgba(10, 12, 16, .74);
  color: var(--text-dim); font-size: 13px; line-height: 1;
  display: none; align-items: center; justify-content: center;
  cursor: pointer; backdrop-filter: blur(4px);
  transition: background .15s, color .15s, border-color .15s;
}
.book-card:hover .book-del { display: flex; }
.book-del:hover { background: var(--red); color: #fff; border-color: var(--red); }
.book-cover {
  aspect-ratio: 3 / 4; width: 100%; object-fit: cover; background: var(--bg-elev2);
  display: block;
}
.book-body { padding: 10px 12px 12px; display: flex; flex-direction: column; gap: 5px; flex: 1; }
.book-title {
  font-size: 14px; font-weight: 650; line-height: 1.35; color: var(--text);
  display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden;
}
.book-author { font-size: 12px; color: var(--text-dim); }
.book-summary {
  font-size: 12px; color: var(--text-faint); line-height: 1.5; margin-top: 2px;
  display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden;
}
.book-foot { margin-top: auto; display: flex; align-items: center; gap: 6px; padding-top: 6px; }
.fmt-tag {
  font-size: 10px; font-weight: 700; padding: 2px 7px; border-radius: 6px;
  background: var(--bg-elev2); color: var(--text-dim); letter-spacing: .5px;
}
.fmt-pdf { color: var(--red); }
.fmt-epub { color: var(--blue); }
.fmt-txt { color: var(--green); }
.share-dot { margin-left: auto; font-size: 11px; color: var(--amber); }

/* ---------------- Empty / loading ---------------- */
.empty-state { text-align: center; color: var(--text-faint); padding: 60px 20px; }
.empty-state .big { font-size: 42px; margin-bottom: 10px; }
.skeleton { background: linear-gradient(90deg, var(--bg-elev), var(--bg-elev2), var(--bg-elev)); background-size: 200% 100%; animation: shimmer 1.2s infinite; }
@keyframes shimmer { to { background-position: -200% 0; } }

/* ---------------- Modal ---------------- */
.modal-mask {
  position: fixed; inset: 0; z-index: 100; background: rgba(0,0,0,.55);
  display: none; align-items: flex-start; justify-content: center; padding: 40px 14px;
  backdrop-filter: blur(3px); overflow-y: auto;
}
.modal-mask.open { display: flex; }
.modal {
  width: 100%; max-width: 720px; background: var(--bg-elev);
  border: 1px solid var(--border); border-radius: 16px; box-shadow: var(--shadow);
  max-height: 86vh; display: flex; flex-direction: column; overflow: hidden;
}
.modal-head { display: flex; align-items: center; gap: 10px; padding: 16px 18px; border-bottom: 1px solid var(--border); }
.modal-head h3 { margin: 0; font-size: 16px; }
.modal-body { padding: 16px 18px; overflow-y: auto; }
.modal-foot { padding: 12px 18px; border-top: 1px solid var(--border); display: flex; gap: 10px; }
.input {
  width: 100%; height: 40px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--bg-elev2); color: var(--text); padding: 0 14px; font-size: 14px; outline: none;
}
.input:focus { border-color: var(--brand); }
.btn {
  height: 40px; padding: 0 18px; border-radius: 10px; border: 1px solid var(--border);
  background: var(--bg-elev2); color: var(--text); font-size: 14px; font-weight: 600;
  transition: all .18s; white-space: nowrap;
}
.btn:hover { border-color: var(--text-faint); }
.btn-primary { background: var(--brand); border-color: var(--brand); color: #fff; }
.btn-primary:hover { background: #b80029; }
.btn:disabled { opacity: .5; cursor: not-allowed; }

.result-item {
  border: 1px solid var(--border); border-radius: 10px; padding: 12px 14px; margin-bottom: 10px;
  background: var(--bg-elev2);
}
.result-item .rt { font-size: 13px; font-weight: 600; margin-bottom: 6px; word-break: break-all; }
.result-item .rmeta { font-size: 12px; color: var(--text-dim); display: flex; gap: 10px; flex-wrap: wrap; align-items: center; }
.link-copy { color: var(--blue); font-size: 12px; cursor: pointer; }
.share-list { margin-top: 14px; }
.share-list h4 { font-size: 13px; color: var(--text-dim); margin: 0 0 8px; }

/* ---------------- Toast ---------------- */
.toast-wrap { position: fixed; bottom: 24px; left: 50%; transform: translateX(-50%); z-index: 200; display: flex; flex-direction: column; gap: 8px; align-items: center; }
.toast {
  background: var(--bg-elev); border: 1px solid var(--border); color: var(--text);
  padding: 11px 18px; border-radius: 10px; box-shadow: var(--shadow); font-size: 13px;
  animation: toastIn .25s ease; max-width: 90vw;
}
.toast.err { border-color: var(--red); color: var(--red); }
.toast.ok { border-color: var(--green); color: var(--green); }
@keyframes toastIn { from { opacity: 0; transform: translateY(10px); } }

/* ---------------- Reader ---------------- */
.reader-top {
  position: sticky; top: 0; z-index: 20; display: flex; align-items: center; gap: 12px;
  height: var(--header-h); padding: 0 16px;
  background: color-mix(in srgb, var(--bg-elev) 85%, transparent); backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.reader-top .title { font-size: 14px; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.reader-stage { position: fixed; inset: var(--header-h) 0 var(--reader-ctl-space) 0; overflow: auto; background: var(--bg); }
.reader-controls button.active { color: #fff; background: var(--brand); }
.reader-stage.hand-on { cursor: grab; }
.reader-stage.hand-on.grabbing { cursor: grabbing; }
#pdf-canvas { display: block; margin: 0 auto; }
.txt-reader {
  max-width: 760px; margin: 0 auto; padding: 32px 22px 80px; line-height: 1.9; font-size: 17px;
  color: var(--text); white-space: pre-wrap; word-break: break-word; overflow-y: auto; height: 100%;
  box-sizing: border-box;
}
.reader-controls {
  position: fixed; bottom: calc(18px + env(safe-area-inset-bottom, 0px)); left: 50%; transform: translateX(-50%); z-index: 30;
  display: flex; align-items: center; gap: 8px; padding: 8px 12px;
  background: var(--bg-elev); border: 1px solid var(--border); border-radius: 30px; box-shadow: var(--shadow);
}
.reader-controls button { width: 38px; height: 38px; border-radius: 50%; border: none; background: var(--bg-elev2); color: var(--text); font-size: 16px; }
.reader-controls button:hover { color: var(--brand); }
.reader-controls .pg { font-size: 12px; color: var(--text-dim); min-width: 64px; text-align: center; }
#epub-root { width: 100%; height: 100%; }
#epub-root iframe { border: none; width: 100%; height: 100%; }

/* 不支持的格式：仅下载提示 */
.unsupported { max-width: 540px; margin: 10vh auto 0; padding: 0 20px; text-align: center; color: var(--text); }
.unsupported .u-badge {
  display: inline-block; padding: 4px 16px; border-radius: 20px; margin-bottom: 20px;
  background: var(--bg-elev2); border: 1px solid var(--border);
  font-weight: 700; letter-spacing: 1px; font-size: 15px;
}
.unsupported .u-title { font-size: 20px; font-weight: 700; margin-bottom: 14px; line-height: 1.5; }
.unsupported .u-tip { font-size: 14px; line-height: 1.9; color: var(--text-dim); margin-bottom: 28px; }
.unsupported .dl-btn {
  display: inline-flex; align-items: center; gap: 8px; padding: 13px 30px; border-radius: 24px;
  background: var(--brand); color: #fff; font-weight: 600; text-decoration: none; transition: .15s;
}
.unsupported .dl-btn:hover { background: #b80029; transform: translateY(-1px); }

/* ---------------- Responsive ---------------- */
@media (max-width: 640px) {
  .brand-name small { display: none; }
  .book-grid { grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); gap: 12px; padding: 12px 12px 50px; }
  .search-box { max-width: none; }
  .toolbar { padding: 10px 12px 2px; }
  .reader-controls { bottom: calc(12px + env(safe-area-inset-bottom, 0px)); gap: 4px; padding: 6px 8px; }
  .reader-controls button { width: 34px; height: 34px; font-size: 15px; }
  .reader-controls .pg { min-width: 46px; }
  /* 工具栏已占用独立条带 (--reader-ctl-space)，正文无需再加底部留白 */
  .txt-reader { padding-bottom: 24px; }
  #pdf-canvas { margin-bottom: 14px; }
}

/* ---------------- 下载进度条 ---------------- */
.dl-progress {
  margin: 0 16px 4px; padding: 12px 14px; border-radius: 12px;
  background: var(--bg-elev2); border: 1px solid var(--border);
  display: flex; flex-direction: column; gap: 8px;
}
.dl-progress .dl-head { display: flex; align-items: center; gap: 8px; font-size: 13px; font-weight: 600; }
.dl-progress .dl-dot {
  width: 8px; height: 8px; border-radius: 50%; background: var(--brand, #D50030);
  animation: dlPulse 1.2s ease-in-out infinite; flex-shrink: 0;
}
.dl-progress.done .dl-dot { background: #3ecf6f; animation: none; }
.dl-progress.stopped .dl-dot, .dl-progress.error .dl-dot { background: #e6a23c; animation: none; }
@keyframes dlPulse { 0%,100% { opacity: 1; } 50% { opacity: .25; } }
.dl-bar {
  height: 6px; border-radius: 4px; background: var(--bg, #1a1e26);
  border: 1px solid var(--border); overflow: hidden;
}
.dl-fill {
  height: 100%; width: 0; border-radius: 4px;
  background: linear-gradient(90deg, var(--brand, #D50030), #ff4d6d);
  transition: width .6s ease;
}
.dl-progress .dl-foot { display: flex; align-items: center; gap: 8px; font-size: 12px; }
.dl-log {
  font-size: 11px; color: var(--text-dim); line-height: 1.7;
  max-height: 88px; overflow: hidden; font-family: monospace;
  border-top: 1px dashed var(--border); padding-top: 6px;
}
/* 折叠态：只留标题行 */
.dl-progress.collapsed { padding: 8px 14px; gap: 0; }
.dl-progress.collapsed .dl-bar,
.dl-progress.collapsed .dl-foot,
.dl-progress.collapsed .dl-log { display: none; }
.dl-progress .dl-head { cursor: pointer; }
.dl-progress .dl-toggle, .dl-progress .dl-close {
  background: none; border: none; color: var(--text-dim);
  font-size: 14px; line-height: 1; padding: 2px 4px; cursor: pointer; flex-shrink: 0;
}
.dl-progress .dl-toggle { transition: transform .2s ease; }
.dl-progress.collapsed .dl-toggle { transform: rotate(-90deg); }
.dl-progress .dl-close { font-size: 16px; }
.dl-progress .dl-toggle:hover, .dl-progress .dl-close:hover { color: var(--text, #e6e6e6); }