/* ===== Essentials of Fire Fighting — Study App ===== */
/* Visual identity: ember-on-graphite. Type: Oswald (display, condensed, industrial)
   + Inter (body). Accent = ember orange. Structure = numbered chapter spine. */

:root[data-theme="dark"] {
  --bg: #14171c;
  --bg-2: #1a1e25;
  --surface: #1f242c;
  --surface-2: #262c36;
  --surface-hi: #2e3540;
  --border: #333a45;
  --border-hi: #434c59;
  --text: #eef1f5;
  --text-2: #aeb6c2;
  --text-3: #79828f;
  --ember: #ff5a1f;
  --ember-soft: #ff8a5c;
  --ember-bg: rgba(255, 90, 31, 0.13);
  --ember-border: rgba(255, 90, 31, 0.4);
  --steel: #4d9be6;
  --steel-bg: rgba(77, 155, 230, 0.12);
  --good: #3ecf8e;
  --good-bg: rgba(62, 207, 142, 0.13);
  --good-border: rgba(62, 207, 142, 0.4);
  --bad: #ff5f6d;
  --bad-bg: rgba(255, 95, 109, 0.13);
  --bad-border: rgba(255, 95, 109, 0.4);
  --shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

:root[data-theme="light"] {
  --bg: #f4f2ee;
  --bg-2: #ebe8e2;
  --surface: #ffffff;
  --surface-2: #f7f5f1;
  --surface-hi: #efece6;
  --border: #ddd8cf;
  --border-hi: #cbc4b8;
  --text: #1c1f24;
  --text-2: #4d5560;
  --text-3: #8a8579;
  --ember: #d8401a;
  --ember-soft: #e8633f;
  --ember-bg: rgba(216, 64, 26, 0.08);
  --ember-border: rgba(216, 64, 26, 0.35);
  --steel: #2c6fb0;
  --steel-bg: rgba(44, 111, 176, 0.08);
  --good: #1a9d63;
  --good-bg: rgba(26, 157, 99, 0.1);
  --good-border: rgba(26, 157, 99, 0.35);
  --bad: #cc2b3c;
  --bad-bg: rgba(204, 43, 60, 0.08);
  --bad-border: rgba(204, 43, 60, 0.35);
  --shadow: 0 8px 30px rgba(40, 30, 20, 0.12);
}

* { box-sizing: border-box; margin: 0; padding: 0; }

html { -webkit-text-size-adjust: 100%; }

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.55;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

/* ===== Top bar ===== */
.topbar {
  position: sticky; top: 0; z-index: 40;
  display: flex; align-items: center; gap: 14px;
  padding: 12px 18px;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.brand { display: flex; align-items: center; gap: 11px; min-width: 0; }
.brand-mark {
  width: 34px; height: 34px; flex-shrink: 0; border-radius: 9px;
  background: linear-gradient(150deg, var(--ember), #b8260a);
  display: grid; place-items: center;
  box-shadow: 0 3px 12px var(--ember-bg);
}
.brand-mark svg { width: 19px; height: 19px; }
.brand-text { min-width: 0; }
.brand-title {
  font-family: 'Oswald', sans-serif; font-weight: 600;
  font-size: 16px; letter-spacing: 0.04em; text-transform: uppercase;
  line-height: 1.05; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}
.brand-sub { font-size: 11px; color: var(--text-3); letter-spacing: 0.03em; }
.topbar-spacer { flex: 1; }
.icon-btn {
  width: 38px; height: 38px; border-radius: 9px; flex-shrink: 0;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text-2); font-size: 17px; cursor: pointer;
  display: grid; place-items: center; transition: all 0.15s;
}
.icon-btn:hover { border-color: var(--border-hi); color: var(--text); }
.rail-toggle { display: none; }

/* ===== Progress strip ===== */
.progress-strip {
  display: flex; align-items: center; gap: 12px;
  padding: 9px 18px;
  background: var(--bg-2);
  border-bottom: 1px solid var(--border);
  font-size: 12px;
}
.progress-strip .ps-label { color: var(--text-3); letter-spacing: 0.03em; text-transform: uppercase; font-size: 10.5px; font-weight: 600; white-space: nowrap; }
.ps-track { flex: 1; height: 5px; border-radius: 99px; background: var(--surface-hi); overflow: hidden; }
.ps-fill { height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--ember), var(--ember-soft)); transition: width 0.5s ease; }
.ps-val { color: var(--text-2); white-space: nowrap; font-variant-numeric: tabular-nums; }

/* ===== Layout ===== */
.layout { display: flex; align-items: flex-start; max-width: 1240px; margin: 0 auto; }

/* ===== Sidebar (chapter rail) ===== */
.sidebar {
  width: 310px; flex-shrink: 0;
  position: sticky; top: 106px;
  height: calc(100vh - 106px);
  display: flex; flex-direction: column;
  border-right: 1px solid var(--border);
  background: var(--bg);
}
.sec-tabs { padding: 16px 14px 10px; display: flex; flex-direction: column; gap: 5px; }
.sec-tab {
  display: flex; align-items: center; justify-content: space-between;
  padding: 9px 13px; border-radius: 9px; cursor: pointer;
  border: 1px solid transparent; background: transparent;
  color: var(--text-2); transition: all 0.15s; text-align: left; width: 100%;
}
.sec-tab:hover { background: var(--surface); }
.sec-tab.active { background: var(--ember-bg); border-color: var(--ember-border); color: var(--ember-soft); }
.sec-tab-label { font-family: 'Oswald', sans-serif; font-size: 14px; letter-spacing: 0.04em; text-transform: uppercase; font-weight: 500; }
.sec-tab-count { font-size: 11px; color: var(--text-3); font-variant-numeric: tabular-nums; }
.sec-tab.active .sec-tab-count { color: var(--ember-soft); }

.rail-heading { padding: 8px 18px 6px; font-size: 10.5px; letter-spacing: 0.08em; text-transform: uppercase; color: var(--text-3); font-weight: 600; }
.chapter-rail { flex: 1; overflow-y: auto; padding: 0 12px 24px; display: flex; flex-direction: column; gap: 4px; }
.ch-pill {
  display: flex; align-items: stretch; gap: 11px;
  padding: 9px 11px; border-radius: 10px; cursor: pointer;
  border: 1px solid transparent; background: transparent;
  color: var(--text); transition: all 0.13s; text-align: left; width: 100%;
}
.ch-pill:hover { background: var(--surface); }
.ch-pill.active { background: var(--surface-2); border-color: var(--border-hi); }
.ch-pill-num {
  font-family: 'Oswald', sans-serif; font-size: 15px; font-weight: 600;
  color: var(--text-3); width: 24px; flex-shrink: 0; display: grid; place-items: center;
  font-variant-numeric: tabular-nums;
}
.ch-pill.active .ch-pill-num { color: var(--ember); }
.ch-pill-body { min-width: 0; flex: 1; display: flex; flex-direction: column; gap: 5px; }
.ch-pill-title { font-size: 13px; line-height: 1.3; font-weight: 500; }
.ch-pill-meta { display: flex; align-items: center; gap: 8px; }
.ch-pill-prog { flex: 1; height: 3px; border-radius: 99px; background: var(--surface-hi); overflow: hidden; }
.ch-pill-fill { height: 100%; background: var(--ember); border-radius: 99px; transition: width 0.4s; }
.ch-pill-badge { font-size: 10px; font-weight: 600; color: var(--steel); background: var(--steel-bg); padding: 1px 6px; border-radius: 99px; font-variant-numeric: tabular-nums; }

/* ===== Main ===== */
.main { flex: 1; min-width: 0; padding: 22px 26px 60px; }
.ch-head { margin-bottom: 18px; }
.ch-head h1 { font-family: 'Oswald', sans-serif; font-size: 26px; font-weight: 600; letter-spacing: 0.02em; line-height: 1.1; }
.ch-head .ch-meta { font-size: 12.5px; color: var(--text-3); margin-top: 3px; }

.mode-tabs { display: flex; gap: 6px; margin-bottom: 22px; border-bottom: 1px solid var(--border); }
.mode-tab {
  padding: 9px 4px; margin-right: 18px; cursor: pointer;
  border: none; background: none; color: var(--text-3);
  font-size: 14px; font-weight: 500; position: relative; transition: color 0.15s;
}
.mode-tab:hover { color: var(--text-2); }
.mode-tab.active { color: var(--text); }
.mode-tab.active::after {
  content: ''; position: absolute; left: 0; right: 0; bottom: -1px; height: 2px;
  background: var(--ember); border-radius: 2px;
}

/* ===== Flashcards ===== */
.flash-stage { perspective: 1400px; margin-bottom: 18px; }
.flashcard {
  position: relative; width: 100%; min-height: 300px;
  transform-style: preserve-3d; transition: transform 0.55s cubic-bezier(.2,.7,.2,1);
  cursor: pointer;
}
.flashcard.flipped { transform: rotateY(180deg); }
.face {
  position: absolute; inset: 0; backface-visibility: hidden;
  border-radius: 18px; border: 1px solid var(--border);
  padding: 32px 30px; display: flex; flex-direction: column;
  background: var(--surface); box-shadow: var(--shadow);
}
.face.front { align-items: center; justify-content: center; text-align: center; }
.face.back { transform: rotateY(180deg); border-color: var(--ember-border); }
.face-tag { font-size: 10.5px; letter-spacing: 0.1em; text-transform: uppercase; font-weight: 600; color: var(--text-3); margin-bottom: 16px; }
.face.back .face-tag { color: var(--ember); }
.face-q { font-family: 'Oswald', sans-serif; font-size: 23px; font-weight: 500; line-height: 1.35; letter-spacing: 0.01em; }
.face-a { font-size: 17px; font-weight: 600; color: var(--ember-soft); line-height: 1.5; margin-bottom: 16px; }
.face-exp { font-size: 14px; color: var(--text-2); line-height: 1.65; border-top: 1px solid var(--border); padding-top: 14px; }
.exp-label { display: block; font-size: 10.5px; letter-spacing: 0.08em; text-transform: uppercase; font-weight: 600; color: var(--text-3); margin-bottom: 6px; }
.flip-hint { font-size: 12px; color: var(--text-3); margin-top: 20px; }

.flash-controls { display: flex; gap: 10px; margin-bottom: 12px; }
.ctrl-btn {
  flex: 1; padding: 12px 16px; border-radius: 11px; cursor: pointer;
  border: 1px solid var(--border-hi); background: var(--surface);
  color: var(--text); font-size: 14px; font-weight: 500; transition: all 0.15s;
  font-family: inherit;
}
.ctrl-btn:hover:not(:disabled) { background: var(--surface-2); border-color: var(--text-3); }
.ctrl-btn:disabled { opacity: 0.35; cursor: default; }
.ctrl-btn.primary { background: var(--ember); border-color: var(--ember); color: #fff; }
.ctrl-btn.primary:hover { background: var(--ember-soft); border-color: var(--ember-soft); }
.ctrl-learn.is-learned { background: var(--good-bg); border-color: var(--good-border); color: var(--good); }
.flash-tools { display: flex; justify-content: space-between; gap: 12px; }
.text-btn { background: none; border: none; color: var(--text-3); font-size: 13px; cursor: pointer; font-family: inherit; padding: 4px 2px; transition: color 0.15s; }
.text-btn:hover { color: var(--ember); }

/* ===== Quiz ===== */
.quiz-top { display: flex; align-items: center; gap: 12px; margin-bottom: 18px; }
.quiz-track { flex: 1; height: 5px; border-radius: 99px; background: var(--surface-hi); overflow: hidden; }
.quiz-fill { height: 100%; background: var(--ember); border-radius: 99px; transition: width 0.4s; }
.quiz-counter { font-size: 12px; color: var(--text-3); white-space: nowrap; font-variant-numeric: tabular-nums; }
.quiz-q { font-family: 'Oswald', sans-serif; font-size: 20px; font-weight: 500; line-height: 1.4; margin-bottom: 20px; letter-spacing: 0.01em; }
.quiz-opts { display: flex; flex-direction: column; gap: 9px; margin-bottom: 16px; }
.q-opt {
  display: flex; align-items: center; gap: 13px;
  padding: 14px 16px; border-radius: 12px; cursor: pointer;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); text-align: left; transition: all 0.15s; font-family: inherit;
}
.q-opt:hover:not(:disabled) { border-color: var(--border-hi); background: var(--surface-2); }
.q-letter {
  width: 26px; height: 26px; border-radius: 7px; flex-shrink: 0;
  display: grid; place-items: center; font-size: 13px; font-weight: 600;
  background: var(--surface-hi); color: var(--text-2);
  font-family: 'Oswald', sans-serif;
}
.q-text { font-size: 14.5px; line-height: 1.4; }
.q-opt.correct { background: var(--good-bg); border-color: var(--good-border); }
.q-opt.correct .q-letter { background: var(--good); color: #fff; }
.q-opt.wrong { background: var(--bad-bg); border-color: var(--bad-border); }
.q-opt.wrong .q-letter { background: var(--bad); color: #fff; }
.q-opt.dim { opacity: 0.5; }
.q-feedback { padding: 14px 16px; border-radius: 12px; font-size: 13.5px; line-height: 1.65; margin-bottom: 16px; }
.q-feedback.good { background: var(--good-bg); color: var(--text); border: 1px solid var(--good-border); }
.q-feedback.bad { background: var(--bad-bg); color: var(--text); border: 1px solid var(--bad-border); }
.q-feedback strong { color: var(--text); }
.q-advance { width: 100%; }

/* Quiz result */
.quiz-result { text-align: center; padding: 24px 0 8px; }
.result-head { font-family: 'Oswald', sans-serif; font-size: 22px; font-weight: 600; text-transform: uppercase; letter-spacing: 0.03em; }
.result-ring {
  --p: 0;
  width: 150px; height: 150px; border-radius: 50%; margin: 22px auto 16px;
  display: grid; place-items: center;
  background: conic-gradient(var(--ember) calc(var(--p) * 1%), var(--surface-hi) 0);
  position: relative;
}
.result-ring::before { content: ''; position: absolute; inset: 12px; border-radius: 50%; background: var(--bg); }
.result-pct { position: relative; font-family: 'Oswald', sans-serif; font-size: 40px; font-weight: 600; font-variant-numeric: tabular-nums; }
.result-pct small { font-size: 18px; color: var(--text-3); }
.result-line { font-size: 14px; color: var(--text-2); margin-bottom: 22px; }
.result-actions { display: flex; gap: 10px; max-width: 380px; margin: 0 auto; }

/* ===== Terms ===== */
.terms-list { display: flex; flex-direction: column; gap: 9px; }
.term {
  padding: 14px 17px; border-radius: 12px;
  border: 1px solid var(--border); background: var(--surface);
  border-left: 3px solid var(--ember);
}
.term-name { display: block; font-family: 'Oswald', sans-serif; font-size: 15px; font-weight: 500; letter-spacing: 0.02em; color: var(--ember-soft); margin-bottom: 3px; }
.term-def { font-size: 14px; color: var(--text-2); line-height: 1.6; }

/* ===== Notes ===== */
.notes { display: flex; flex-direction: column; gap: 8px; }
.notes-label { font-size: 12px; color: var(--text-3); font-weight: 500; letter-spacing: 0.02em; }
.notes-area {
  width: 100%; min-height: 280px; resize: vertical;
  padding: 16px; border-radius: 12px;
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); font-family: inherit; font-size: 14.5px; line-height: 1.7;
}
.notes-area:focus { outline: none; border-color: var(--ember-border); }
.notes-foot { display: flex; justify-content: flex-end; }
.notes-status { font-size: 12px; color: var(--text-3); }

/* ===== Scrim (mobile drawer) ===== */
.scrim { display: none; position: fixed; inset: 0; z-index: 30; background: rgba(0,0,0,0.5); opacity: 0; transition: opacity 0.2s; }
.scrim.show { display: block; opacity: 1; }

/* ===== Responsive ===== */
@media (max-width: 880px) {
  .rail-toggle { display: grid; }
  .sidebar {
    position: fixed; top: 0; left: 0; z-index: 35;
    height: 100vh; width: 290px;
    transform: translateX(-100%); transition: transform 0.25s ease;
    box-shadow: var(--shadow);
  }
  .sidebar.open { transform: translateX(0); }
  .main { padding: 18px 16px 60px; }
  .ch-head h1 { font-size: 22px; }
  .face-q { font-size: 20px; }
  .face { padding: 26px 22px; }
  .quiz-q { font-size: 18px; }
  .result-actions { flex-direction: column; }
  .brand-sub { display: none; }
}

@media (max-width: 460px) {
  .topbar { padding: 10px 14px; gap: 10px; }
  .progress-strip { padding: 8px 14px; }
  .ps-label { display: none; }
  .flash-controls { flex-wrap: wrap; }
  .ctrl-learn { order: 3; flex-basis: 100%; }
}

/* ===== Lesson (Interactive Walkthrough) ===== */
.lesson-container { display: flex; flex-direction: column; gap: 0; }
.lesson-progress { margin-bottom: 20px; display: flex; align-items: center; gap: 12px; }
.lesson-prog-track { flex: 1; height: 6px; border-radius: 99px; background: var(--surface-hi); overflow: hidden; }
.lesson-prog-fill { height: 100%; border-radius: 99px; background: linear-gradient(90deg, var(--ember), var(--ember-soft)); transition: width 0.5s ease; }
.lesson-prog-label { font-size: 12px; color: var(--text-3); white-space: nowrap; font-variant-numeric: tabular-nums; }

.lesson-card {
  padding: 28px 26px; border-radius: 16px;
  border: 1px solid var(--border); background: var(--surface);
  box-shadow: var(--shadow);
  animation: lessonFadeIn 0.35s ease;
}
@keyframes lessonFadeIn {
  from { opacity: 0; transform: translateY(12px); }
  to { opacity: 1; transform: translateY(0); }
}

.lesson-icon { font-size: 36px; margin-bottom: 12px; }
.lesson-card-title { font-family: 'Oswald', sans-serif; font-size: 22px; font-weight: 600; line-height: 1.2; margin-bottom: 14px; letter-spacing: 0.02em; }
.lesson-card-body { font-size: 14.5px; line-height: 1.75; color: var(--text-2); margin-bottom: 20px; }
.lesson-card-body p { margin-bottom: 10px; }
.lesson-card-body ul, .lesson-card-body ol { padding-left: 22px; margin-bottom: 10px; }
.lesson-card-body li { margin-bottom: 5px; }
.lesson-card-body strong { color: var(--text); font-weight: 600; }

.lesson-section-tag {
  display: inline-block; font-family: 'Oswald', sans-serif; font-size: 11px; font-weight: 600;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--steel);
  background: var(--steel-bg); padding: 3px 10px; border-radius: 6px; margin-bottom: 10px;
}

.lesson-check-tag {
  display: inline-block; font-family: 'Oswald', sans-serif; font-size: 12px; font-weight: 600;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--ember);
  background: var(--ember-bg); padding: 4px 12px; border-radius: 6px; margin-bottom: 14px;
  border: 1px solid var(--ember-border);
}

.lesson-check-card { border-color: var(--ember-border); }
.lesson-check-card .quiz-q { margin-top: 4px; }

.lesson-nav { display: flex; gap: 10px; margin-top: 20px; }
.lesson-nav .ctrl-btn { flex: 1; }

.lesson-start { width: 100%; margin-top: 8px; }

.lesson-intro { text-align: center; }
.lesson-intro .lesson-card-body { text-align: left; }

.lesson-complete-card { text-align: center; padding: 40px 26px; }
.lesson-complete-icon { font-size: 52px; margin-bottom: 12px; }
.lesson-complete-sub { font-size: 14px; color: var(--text-2); margin-bottom: 16px; }
.lesson-complete-bar-wrap { max-width: 300px; margin: 0 auto 24px; }
.lesson-complete-actions { display: flex; gap: 10px; max-width: 400px; margin: 0 auto; }

.lesson-tips-card .lesson-icon { text-align: center; }

@media (max-width: 880px) {
  .lesson-card { padding: 22px 18px; }
  .lesson-card-title { font-size: 19px; }
  .lesson-complete-actions { flex-direction: column; }
}

/* ===== Study Guide ===== */
.guide-container { display: flex; flex-direction: column; gap: 24px; }
.guide-section { padding: 20px 22px; border-radius: 14px; border: 1px solid var(--border); background: var(--surface); }
.guide-heading { font-family: 'Oswald', sans-serif; font-size: 18px; font-weight: 600; letter-spacing: 0.03em; text-transform: uppercase; color: var(--ember); margin-bottom: 12px; }
.guide-sub { font-family: 'Oswald', sans-serif; font-size: 16px; font-weight: 500; color: var(--ember-soft); margin-bottom: 10px; letter-spacing: 0.02em; }
.guide-body { font-size: 14.5px; line-height: 1.75; color: var(--text-2); }
.guide-body p { margin-bottom: 10px; }
.guide-body ul, .guide-body ol { padding-left: 22px; margin-bottom: 10px; }
.guide-body li { margin-bottom: 5px; }
.guide-body strong { color: var(--text); font-weight: 600; }
.guide-overview { border-left: 3px solid var(--ember); }
.guide-concept { border-left: 3px solid var(--steel); }
.guide-questions { padding-left: 22px; font-size: 14.5px; line-height: 1.75; color: var(--text-2); }
.guide-questions li { margin-bottom: 8px; }
.guide-questions li::marker { color: var(--ember); font-weight: 600; }
.guide-tips-list { display: flex; flex-direction: column; gap: 10px; }
.guide-tip { font-size: 14px; line-height: 1.65; color: var(--text-2); padding: 12px 14px; border-radius: 10px; background: var(--ember-bg); border: 1px solid var(--ember-border); }
.tip-badge { display: inline-block; font-family: 'Oswald', sans-serif; font-size: 10.5px; font-weight: 600; letter-spacing: 0.08em; text-transform: uppercase; color: var(--ember); margin-right: 8px; padding: 2px 7px; border-radius: 5px; background: var(--surface); border: 1px solid var(--ember-border); vertical-align: middle; }
.guide-empty { text-align: center; padding: 60px 20px; color: var(--text-3); font-size: 15px; }

/* ===== Guide/Lesson Figures ===== */
.guide-figure { margin: 16px 0 8px; border-radius: 12px; overflow: hidden; border: 1px solid var(--border); background: var(--surface-2); }
.guide-img { display: block; width: 100%; height: auto; border-bottom: 1px solid var(--border); }
.guide-figcap { padding: 10px 14px; font-size: 12.5px; line-height: 1.55; color: var(--text-2); }
.guide-figcap strong { color: var(--ember-soft); font-weight: 600; }

/* ===== Walkthrough ===== */
.wt-overlay { position: fixed; inset: 0; z-index: 9999; }
.wt-backdrop { position: absolute; inset: 0; background: rgba(0,0,0,0.65); }
.wt-highlight { position: absolute; box-shadow: 0 0 0 4000px rgba(0,0,0,0.65); z-index: 1; border: 2px solid var(--ember); pointer-events: none; }
.wt-tooltip { position: fixed; z-index: 2; width: 320px; max-width: calc(100vw - 32px); padding: 20px; border-radius: 14px; background: var(--surface); border: 1px solid var(--border-hi); box-shadow: 0 12px 40px rgba(0,0,0,0.5); }
.wt-step-count { font-size: 11px; color: var(--text-3); letter-spacing: 0.06em; text-transform: uppercase; font-weight: 600; margin-bottom: 6px; }
.wt-title { font-family: 'Oswald', sans-serif; font-size: 18px; font-weight: 600; color: var(--text); margin-bottom: 6px; }
.wt-text { font-size: 14px; line-height: 1.6; color: var(--text-2); margin-bottom: 16px; }
.wt-actions { display: flex; gap: 10px; justify-content: flex-end; }
.wt-btn { padding: 8px 16px; border-radius: 9px; cursor: pointer; font-size: 13px; font-weight: 500; font-family: inherit; border: 1px solid var(--border-hi); background: var(--surface-2); color: var(--text); transition: all 0.15s; }
.wt-btn:hover { border-color: var(--text-3); }
.wt-next { background: var(--ember); border-color: var(--ember); color: #fff; }
.wt-next:hover { background: var(--ember-soft); border-color: var(--ember-soft); }
.wt-skip { background: transparent; border-color: transparent; color: var(--text-3); }
.wt-skip:hover { color: var(--text-2); }

@media (max-width: 880px) {
  .wt-tooltip { width: calc(100vw - 32px); left: 16px !important; right: 16px !important; }
  .wt-highlight { display: none; }
}

/* Scrollbar */
.chapter-rail::-webkit-scrollbar { width: 8px; }
.chapter-rail::-webkit-scrollbar-thumb { background: var(--border-hi); border-radius: 99px; }
.chapter-rail::-webkit-scrollbar-track { background: transparent; }