/* =========================================================
   SQUARE ROOT ARENA  — single-file gamified aptitude trainer
   ========================================================= */
:root {
  --bg: #0b1020;
  --bg2: #11173a;
  --ink: #eaf0ff;
  --muted: #a6b0d6;
  --glass: rgba(255, 255, 255, 0.08);
  --glass-2: rgba(255, 255, 255, 0.14);
  --stroke: rgba(255, 255, 255, 0.16);
  --p1: #7c5cff;
  --p2: #22d3ee;
  --p3: #f472b6;
  --ok: #22c55e;
  --bad: #ef4444;
  --warn: #f59e0b;
  --gold: #ffd66b;
  --radius: 18px;
  --shadow:
    0 20px 60px -20px rgba(0, 0, 0, 0.6),
    0 8px 24px -12px rgba(124, 92, 255, 0.45);
  --t: cubic-bezier(0.2, 0.8, 0.2, 1);
}
* {
  box-sizing: border-box;
}
html,
body {
  margin: 0;
  padding: 0;
  height: 100%;
}
body {
  font-family:
    ui-sans-serif,
    system-ui,
    -apple-system,
    "Segoe UI",
    Roboto,
    "Helvetica Neue",
    Arial,
    "Noto Sans",
    sans-serif;
  color: var(--ink);
  background:
    radial-gradient(
      1200px 600px at 10% -10%,
      rgba(124, 92, 255, 0.35),
      transparent 60%
    ),
    radial-gradient(
      900px 500px at 110% 10%,
      rgba(34, 211, 238, 0.25),
      transparent 60%
    ),
    radial-gradient(
      700px 500px at 50% 120%,
      rgba(244, 114, 182, 0.25),
      transparent 60%
    ),
    linear-gradient(180deg, #070a1a, #0b1020 40%, #0a0f25);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
canvas#particles {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  opacity: 0.6;
}
.app {
  position: relative;
  z-index: 1;
  max-width: 1180px;
  margin: 0 auto;
  padding: 18px 18px 80px;
}
header.top {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 14px 16px;
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--glass-2), var(--glass));
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  margin-bottom: 18px;
}
.top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.bottom-row {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
}
.backbtn {
  appearance: none;
  background: transparent;
  border: 1px solid transparent;
  color: var(--ink);
  opacity: 0.8; /* 20% lighter than before */
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px 8px 0;
  border-radius: 10px;
  cursor: pointer;
  font-weight: 600;
  font-size: 13px;
  transition: background 0.2s var(--t);
}
.backbtn:hover {
  background: var(--glass-2);
}
.backbtn svg {
  width: 16px;
  height: 16px;
}
.page-title {
  margin: 0;
  font-size: 24px;
  font-weight: 700;
  letter-spacing: 0.2px;
}
.stat {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 12px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  font-weight: 600;
  font-size: 13px;
}
.stat-group {
  display: flex;
  align-items: center;
  gap: 8px;
}
@media (max-width: 640px) {
  .top-row {
    flex-wrap: wrap;
  }
  .page-title {
    font-size: 20px;
  }
}
.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: 0.3px;
}
.logo .badge {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  display: grid;
  place-items: center;
  background: conic-gradient(
    from 210deg,
    var(--p1),
    var(--p2),
    var(--p3),
    var(--p1)
  );
  box-shadow: 0 6px 24px rgba(124, 92, 255, 0.5);
}
.logo .badge svg {
  width: 22px;
  height: 22px;
}
.logo small {
  display: block;
  font-weight: 500;
  color: var(--muted);
  font-size: 11px;
  margin-top: -2px;
}
.spacer {
  flex: 1;
}
.stat {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 12px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  font-weight: 600;
  font-size: 13px;
}
.stat b {
  color: var(--gold);
}
.stat.streak b {
  color: var(--p3);
}
.stat.rank b {
  color: var(--p2);
}
.stat .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--p2);
  box-shadow: 0 0 12px var(--p2);
}
.lang-select {
  appearance: none;
  background: var(--glass);
  border: 1px solid var(--stroke);
  color: var(--ink);
  padding: 8px 28px 8px 12px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--ink) 50%),
    linear-gradient(135deg, var(--ink) 50%, transparent 50%);
  background-position:
    calc(100% - 14px) 50%,
    calc(100% - 9px) 50%;
  background-size:
    5px 5px,
    5px 5px;
  background-repeat: no-repeat;
}
.lang-select option {
  background: #11173a;
  color: var(--ink);
}
.grid {
  display: grid;
  gap: 18px;
  grid-template-columns: 1fr 1fr;
}
.grid > * {
  min-width: 0;
}
.capsule-tabs {
  position: relative;
  display: flex;
  gap: 6px;
  padding: 6px;
  margin-bottom: 16px;
  background: linear-gradient(
    180deg,
    rgba(255, 255, 255, 0.06),
    rgba(255, 255, 255, 0.03)
  );
  border: 1px solid var(--stroke);
  border-radius: 999px;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    0 6px 18px -10px rgba(0, 0, 0, 0.55);
}
.capsule-tab {
  flex: 1;
  position: relative;
  z-index: 1;
  appearance: none;
  border: none;
  background: transparent;
  color: var(--muted);
  font: inherit;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.2px;
  padding: 10px 18px;
  border-radius: 999px;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition:
    color 0.25s var(--t),
    transform 0.25s var(--t);
  white-space: nowrap;
}
.capsule-tab:hover:not(.active) {
  color: var(--ink);
  transform: translateY(-1px);
}
.capsule-tab:focus-visible {
  outline: 2px solid var(--p2);
  outline-offset: 2px;
}
.capsule-tab.active {
  color: #fff;
}
/* sliding gradient pill behind the active tab -- ONLY this moves/bounces, the tab + container stay put */
.capsule-ind {
  position: absolute;
  left: 0;
  top: 6px;
  z-index: 0;
  border-radius: 999px;
  background: linear-gradient(
    135deg,
    var(--p1) 0%,
    #5b8bff 50%,
    var(--p2) 100%
  );
  box-shadow:
    0 8px 22px -8px rgba(124, 92, 255, 0.65),
    0 4px 12px -6px rgba(34, 211, 238, 0.45),
    inset 0 1px 0 rgba(255, 255, 255, 0.25);
  transition:
    transform 0.3s cubic-bezier(.34, 1.08, .6, 1),
    width 0.3s cubic-bezier(.34, 1.08, .6, 1);
  pointer-events: none;
}
.capsule-ind::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 999px;
  background: radial-gradient(
    120% 60% at 50% 0%,
    rgba(255, 255, 255, 0.35),
    transparent 60%
  );
  pointer-events: none;
  mix-blend-mode: overlay;
}
.tab-content {
  transition: opacity 0.2s;
}
@media (max-width: 980px) {
  .grid {
    display: flex;
    flex-direction: column;
    gap: 8px;
  }
  header.top {
    margin-bottom: 8px;
  }
  .side {
    display: contents;
  }
  #modeCard {
    order: 1;
  }
  .q-card {
    order: 2;
  }
  .tipsCard {
    order: 5;
  }
  #tabSetup:not(.hide) .slider-wrap {
    padding-bottom: 16px;
  }
}

.q-lang-select {
  appearance: none;
  background: var(--glass);
  border: 1px solid var(--stroke);
  color: var(--ink);
  padding: 6px 24px 6px 10px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 400;
  text-transform: lowercase;
  font-variant: normal;
  cursor: pointer;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--ink) 50%),
    linear-gradient(135deg, var(--ink) 50%, transparent 50%);
  background-position:
    calc(100% - 12px) 50%,
    calc(100% - 7px) 50%;
  background-size:
    4px 4px,
    4px 4px;
  background-repeat: no-repeat;
}
.q-lang-select option {
  background: #11173a;
  color: var(--ink);
  text-transform: lowercase;
}
.card {
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  background: linear-gradient(180deg, var(--glass-2), var(--glass));
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  box-shadow: var(--shadow);
  padding: 18px;
}
.card h2 {
  margin: 0 0 6px;
  font-size: 16px;
  letter-spacing: 0.4px;
  text-transform: uppercase;
  color: var(--muted);
  font-weight: 700;
}
.card h3 {
  margin: 0;
  font-size: 18px;
}
.controls {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-bottom: 14px;
}
.chip {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 12px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  font-size: 13px;
  cursor: pointer;
  user-select: none;
  transition:
    transform 0.15s var(--t),
    background 0.2s var(--t),
    border-color 0.2s var(--t);
}
.chip:hover {
  transform: translateY(-1px);
}
.chip.active {
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.45),
    rgba(34, 211, 238, 0.35)
  );
  border-color: transparent;
  box-shadow: 0 6px 20px rgba(124, 92, 255, 0.35);
}
.chip svg {
  width: 14px;
  height: 14px;
}
.slider-row {
  display: flex;
  flex-direction: column;
  gap: 2px;
  flex: 1;
  min-width: 240px;
}
.slider-row .slider-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  font-size: 16px;
  color: var(--t);
  font-weight: 500;
  letter-spacing: 0.01em;
}
.slider-row .slider-head .slider-max {
  color: var(--muted);
  font-size: 14px;
  font-weight: 400;
  margin-left: auto;
}
.slider-wrap {
  position: relative;
  padding: 6px 0 44px;
}
.slider-wrap input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 999px;
  margin: 0;
  background: linear-gradient(90deg, var(--p1), #5b8bff, var(--p2));
  outline: none;
  box-shadow:
    inset 0 1px 2px rgba(0, 0, 0, 0.35),
    0 0 0 1px rgba(255, 255, 255, 0.04);
}
.slider-wrap input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--p1);
  box-shadow:
    0 0 0 4px rgba(124, 92, 255, 0.18),
    0 4px 14px rgba(0, 0, 0, 0.45);
  cursor: pointer;
  transition:
    transform 0.15s ease,
    box-shadow 0.15s ease;
}
.slider-wrap input[type="range"]:hover::-webkit-slider-thumb,
.slider-wrap input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.1);
  box-shadow:
    0 0 0 6px rgba(124, 92, 255, 0.22),
    0 6px 18px rgba(0, 0, 0, 0.5);
}
.slider-wrap input[type="range"]::-moz-range-thumb {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #fff;
  border: 3px solid var(--p1);
  box-shadow:
    0 0 0 4px rgba(124, 92, 255, 0.18),
    0 4px 14px rgba(0, 0, 0, 0.45);
  cursor: pointer;
}
.slider-bubble {
  position: absolute;
  top: 26px;
  left: 0;
  transform: translateX(-50%);
  min-width: 52px;
  padding: 6px 12px;
  border-radius: 10px;
  background: linear-gradient(
    180deg,
    rgba(40, 38, 72, 0.95),
    rgba(28, 26, 52, 0.95)
  );
  border: 1px solid var(--stroke);
  color: var(--t);
  font-size: 14px;
  font-weight: 600;
  text-align: center;
  box-shadow:
    0 4px 12px rgba(0, 0, 0, 0.45),
    inset 0 1px 0 rgba(255, 255, 255, 0.06);
  pointer-events: auto;
  cursor: pointer;
  user-select: none;
}
.q-card {
  position: relative;
  overflow: visible;
}
#modeCard {
  height: fit-content;
  min-height: 0;
}
.q-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  pointer-events: none;
  background: conic-gradient(
    from 0deg,
    transparent 0 70%,
    rgba(124, 92, 255, 0.6) 80%,
    transparent 100%
  );
  filter: blur(20px);
  opacity: 0.35;
  animation: spin 14s linear infinite;
}
@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}
.q-head {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-bottom: 10px;
}
.q-head-row {
  display: flex;
  align-items: center;
  gap: 10px;
  width: 100%;
}
.q-head-row .tagrow {
  flex: 1;
  min-width: 0;
}
.q-head-row .q-lang-select {
  margin-left: auto;
  flex-shrink: 0;
}
@media (max-width: 520px) {
  .q-lang-select {
    font-size: 14px;
    padding: 5px 22px 5px 8px;
    max-width: 140px;
  }
  .q-text {
    font-size: 16px;
  }
}
.tagrow {
  display: flex;
  gap: 6px;
  flex-wrap: wrap;
}
.tag {
  font-size: 11px;
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  color: var(--muted);
}
.tag.hot {
  color: #fff;
  background: linear-gradient(135deg, #ef4444, #f59e0b);
  border-color: transparent;
}
.tag.exam {
  color: #fff;
  background: linear-gradient(135deg, var(--p2), var(--p1));
  border-color: transparent;
}
/* ─── Template Picker ─── */
.tpl-picker {
  position: relative;
  display: inline-flex;
  align-items: center;
}
.tpl-picker-trigger {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  color: var(--muted);
  font-size: 11px;
  transition: all 0.2s var(--t);
  user-select: none;
}
.tpl-picker-trigger:hover {
  border-color: var(--p2);
  color: var(--ink);
  background: rgba(34, 211, 238, 0.08);
}
.tpl-picker-trigger.active {
  border-color: var(--p2);
  color: var(--ink);
  background: rgba(34, 211, 238, 0.1);
}
.tpl-picker-trigger .tpl-label {
  font-weight: 600;
}
.tpl-picker-trigger .tpl-chevron {
  display: inline-flex;
  margin-left: 12px;
  transition: transform 0.2s var(--t);
}
.tpl-picker-trigger.active .tpl-chevron {
  transform: rotate(180deg);
}
.tpl-picker-trigger .tpl-chevron svg {
  width: 12px;
  height: 12px;
}
.tpl-picker-dropdown {
  position: absolute;
  top: calc(100% + 6px);
  left: 0;
  z-index: 999;
  min-width: 260px;
  max-width: 340px;
  background: #151a2e;
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 14px;
  box-shadow: 0 12px 48px rgba(0, 0, 0, 0.7);
  display: none;
  flex-direction: column;
  overflow: hidden;
}
.tpl-picker-dropdown.open {
  display: flex;
}
.tpl-search-wrap {
  position: sticky;
  top: 0;
  z-index: 2;
  padding: 8px;
  background: #151a2e;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}
.tpl-search {
  width: 100%;
  padding: 7px 10px 7px 30px;
  border-radius: 8px;
  border: 1px solid var(--stroke);
  background: rgba(255, 255, 255, 0.06);
  color: var(--ink);
  font-size: 12px;
  font-weight: 500;
  outline: none;
  transition: border-color 0.2s var(--t);
}
.tpl-search:focus {
  border-color: var(--p2);
}
.tpl-search-icon {
  position: absolute;
  left: 16px;
  top: 50%;
  transform: translateY(-50%);
  pointer-events: none;
  color: var(--muted);
}
.tpl-search-icon svg {
  width: 14px;
  height: 14px;
}
.tpl-list {
  overflow-y: auto;
  max-height: 280px;
  padding: 4px 0;
}
.tpl-list::-webkit-scrollbar {
  width: 5px;
}
.tpl-list::-webkit-scrollbar-thumb {
  background: var(--stroke);
  border-radius: 3px;
}
.tpl-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 7px 12px;
  font-size: 12px;
  font-weight: 500;
  color: var(--ink);
  cursor: pointer;
  transition: background 0.15s var(--t);
}
.tpl-item:hover {
  background: rgba(34, 211, 238, 0.08);
}
.tpl-item.selected {
  color: var(--p2);
  font-weight: 700;
}
.tpl-item .tpl-tick {
  width: 16px;
  height: 16px;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  color: var(--p2);
  opacity: 0;
}
.tpl-item.selected .tpl-tick {
  opacity: 1;
}
.tpl-item .tpl-tick svg {
  width: 14px;
  height: 14px;
}
.tpl-item .tpl-item-label {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.tpl-item .tpl-item-tier {
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 999px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.3px;
  flex-shrink: 0;
}
.tpl-item-tier.t-10 {
  background: rgba(34, 197, 94, 0.15);
  color: #22c55e;
}
.tpl-item-tier.t-12 {
  background: rgba(245, 158, 11, 0.15);
  color: #f59e0b;
}
.tpl-item-tier.t-g {
  background: rgba(239, 68, 68, 0.15);
  color: #ef4444;
}
.tpl-group-label {
  padding: 8px 12px 4px;
  font-size: 10px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.5px;
  color: var(--muted);
  cursor: default;
}
.tpl-no-result {
  padding: 16px 12px;
  text-align: center;
  font-size: 12px;
  color: var(--muted);
}
.q-text {
  font-size: 20px;
  line-height: 1.45;
  font-weight: 600;
  margin: 6px 0 12px;
  position: relative;
  word-break: break-word;
  overflow-wrap: break-word;
}
.q-text .num {
  display: inline-block;
  min-width: 1.2em;
  text-align: center;
  padding: 2px 10px;
  border-radius: 10px;
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.35),
    rgba(34, 211, 238, 0.25)
  );
  border: 1px solid var(--stroke);
  margin: 0 3px;
  font-weight: 800;
  transition:
    transform 0.3s var(--t),
    background 0.3s var(--t);
}
.q-text .num.pop {
  animation: pop 0.5s var(--t);
}
@keyframes pop {
  0% {
    transform: scale(0.4) rotate(-8deg);
    filter: blur(4px);
    opacity: 0;
  }
  60% {
    transform: scale(1.15) rotate(2deg);
    filter: blur(0);
    opacity: 1;
  }
  100% {
    transform: scale(1);
  }
}
.answer {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: center;
  margin-top: 6px;
}
.answer input[type="number"] {
  font-size: 22px;
  font-weight: 800;
  color: var(--ink);
  width: 170px;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--stroke);
  background: rgba(0, 0, 0, 0.25);
  outline: none;
  letter-spacing: 0.5px;
  transition:
    border-color 0.2s var(--t),
    box-shadow 0.2s var(--t),
    transform 0.2s var(--t);
}
.answer input[type="number"]:focus {
  border-color: var(--p2);
  box-shadow: 0 0 0 4px rgba(34, 211, 238, 0.18);
}
.answer input.shake {
  animation: shake 0.45s var(--t);
  border-color: var(--bad) !important;
  box-shadow: 0 0 0 4px rgba(239, 68, 68, 0.18) !important;
}
.answer input.good {
  border-color: var(--ok) !important;
  box-shadow: 0 0 0 4px rgba(34, 197, 94, 0.2) !important;
}
@keyframes shake {
  10%,
  90% {
    transform: translateX(-2px);
  }
  20%,
  80% {
    transform: translateX(4px);
  }
  30%,
  50%,
  70% {
    transform: translateX(-8px);
  }
  40%,
  60% {
    transform: translateX(8px);
  }
}
.btn {
  appearance: none;
  border: 0;
  cursor: pointer;
  color: #fff;
  font-weight: 700;
  letter-spacing: 0.3px;
  padding: 12px 16px;
  border-radius: 14px;
  font-size: 14px;
  background: linear-gradient(135deg, var(--p1), var(--p2));
  box-shadow:
    0 8px 24px rgba(124, 92, 255, 0.45),
    inset 0 1px 0 rgba(255, 255, 255, 0.2);
  transition:
    transform 0.15s var(--t),
    filter 0.2s var(--t),
    box-shadow 0.2s var(--t);
}
.btn:hover {
  transform: translateY(-1px);
  filter: brightness(1.06);
}
.btn:active {
  transform: translateY(1px);
}
.btn.ghost {
  background: var(--glass);
  border: 1px solid var(--stroke);
  box-shadow: none;
  color: var(--ink);
}
.btn.ghost:hover {
  background: var(--glass-2);
}
.btn.warn {
  background: linear-gradient(135deg, #f59e0b, #ef4444);
}
.btn.gold {
  background: linear-gradient(135deg, #ffd66b, #f59e0b);
  color: #1a1300;
}
.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 12px;
}
.btn-row > * {
  flex: 1;
}
.mcq {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
  margin-top: 10px;
}
@media (max-width: 520px) {
  .mcq {
    grid-template-columns: 1fr;
  }
}
.opt {
  text-align: left;
  padding: 12px 14px;
  border-radius: 14px;
  border: 1px solid var(--stroke);
  background: var(--glass);
  color: var(--ink);
  font-weight: 600;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  transition:
    transform 0.15s var(--t),
    background 0.2s var(--t),
    border-color 0.2s var(--t);
  word-break: break-word;
  overflow-wrap: break-word;
}
.opt:hover {
  transform: translateY(-1px);
  background: var(--glass-2);
}
.opt .k {
  font-size: 11px;
  color: var(--muted);
  background: rgba(0, 0, 0, 0.25);
  padding: 3px 8px;
  border-radius: 8px;
}
.opt.correct {
  border-color: var(--ok);
  background: rgba(34, 197, 94, 0.15);
}
.opt.wrong {
  border-color: var(--bad);
  background: rgba(239, 68, 68, 0.12);
}
.feedback {
  margin-top: 10px;
  min-height: 22px;
  font-weight: 700;
  word-break: break-word;
  overflow-wrap: break-word;
  line-height: 1.5;
}
.feedback.ok {
  color: var(--ok);
}
.feedback.bad {
  color: var(--bad);
}
.feedback.hint {
  color: var(--gold);
}
.progress {
  height: 10px;
  background: rgba(255, 255, 255, 0.08);
  border-radius: 999px;
  overflow: hidden;
  border: 1px solid var(--stroke);
}
.progress > div {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--p2), var(--p1));
  transition: width 0.6s var(--t);
}
.side {
  display: flex;
  flex-direction: column;
  gap: 16px;
}
.timer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--stroke);
  background: var(--glass);
}
.timer .bar {
  flex: 1;
  margin: 0 10px;
  height: 8px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  overflow: hidden;
}
.timer .bar > div {
  height: 100%;
  width: 100%;
  background: linear-gradient(90deg, var(--ok), var(--warn), var(--bad));
  transition: width 0.9s linear;
}
.timer.off {
  opacity: 0.5;
}
.leader {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.row {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border-radius: 10px;
  background: var(--glass);
  border: 1px solid var(--stroke);
}
.row .pos {
  width: 22px;
  height: 22px;
  border-radius: 6px;
  display: grid;
  place-items: center;
  font-size: 12px;
  font-weight: 800;
  background: linear-gradient(135deg, var(--p1), var(--p2));
}
.row.you {
  outline: 1px solid var(--gold);
}
.row .name {
  flex: 1;
  font-weight: 600;
}
.row .xp {
  font-size: 12px;
  color: var(--muted);
}
.badges {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}
.bdg {
  font-size: 11px;
  padding: 6px 10px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  display: inline-flex;
  align-items: center;
  gap: 6px;
  opacity: 0.5;
}
.bdg.on {
  opacity: 1;
  background: linear-gradient(
    135deg,
    rgba(255, 214, 107, 0.25),
    rgba(244, 114, 182, 0.18)
  );
  border-color: transparent;
  color: #fff;
}
.bdg svg {
  width: 12px;
  height: 12px;
}
.solution {
  margin-top: 14px;
  border-top: 1px dashed var(--stroke);
  padding-top: 14px;
  display: none;
}
.solution.show {
  display: block;
  animation: fadeUp 0.5s cubic-bezier(.34, 1.56, .64, 1); /* bouncy reveal */
}
#solTitle {
  margin-bottom: 16px;
}
.sol-step {
  padding: 10px 12px;
  margin-bottom: 8px;
  background: rgba(255, 255, 255, 0.04);
  border-radius: 10px;
  border-left: 3px solid rgba(124,92,255,.5);
  color: rgba(234,240,255,.72);
  font-size: 14px;
  line-height: 1.7;
  word-break: break-word;
  overflow-wrap: break-word;
  white-space: pre-wrap;
}
.sol-step strong {
  color: #a78bfa;
  display: block;
  margin-bottom: 4px;
}
.sol-formula {
  color: #93c5fd;
  font-weight: 600;
}
.sol-calc {
  color: #e2e8f0;
}
.sol-kyun {
  color: #94a3b8;
  font-style: italic;
}
.sol-kyun::before {
  content: "";
}
.mistake-item {
  padding: 8px 12px;
  margin-bottom: 6px;
  background: rgba(239, 68, 68, 0.08);
  border-radius: 8px;
  border-left: 3px solid var(--bad);
  font-size: 13px;
  line-height: 1.5;
  word-break: break-word;
  overflow-wrap: break-word;
}
.mistake-desc {
  color: var(--bad);
  font-weight: 600;
}
.mistake-why {
  display: block;
  margin-top: 2px;
}
@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}
.method {
  margin-bottom: 14px;
}
.method h4 {
  margin: 0 0 6px;
  font-size: 13px;
  color: #a78bfa;
  text-transform: uppercase;
  letter-spacing: 0.4px;
}
.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}
.pfchip {
  font-size: 12px;
  padding: 6px 10px;
  border-radius: 10px;
  background: rgba(34, 211, 238, 0.15);
  border: 1px solid rgba(34, 211, 238, 0.35);
  color: #cffafe;
  font-weight: 700;
  animation: popIn 0.35s var(--t) both;
}
.pfchip.b {
  background: rgba(244, 114, 182, 0.18);
  border-color: rgba(244, 114, 182, 0.4);
  color: #fde6f3;
}
.pfchip.c {
  background: rgba(124, 92, 255, 0.18);
  border-color: rgba(124, 92, 255, 0.4);
  color: #e6e0ff;
}
.pfchip.common {
  background: linear-gradient(
    135deg,
    rgba(255, 214, 107, 0.35),
    rgba(245, 158, 11, 0.3)
  );
  border-color: transparent;
  color: #fff;
}
@keyframes popIn {
  from {
    transform: scale(0.6);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}
.ladder {
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  font-size: 14px;
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--stroke);
  border-radius: 12px;
  padding: 12px;
  white-space: pre-wrap;
  line-height: 1.6;
}
.ladder .h {
  color: var(--gold);
}
.visual {
  display: flex;
  gap: 18px;
  flex-wrap: wrap;
  margin-top: 6px;
}
.dotgrid {
  padding: 10px;
  border: 1px solid var(--stroke);
  border-radius: 12px;
  background: rgba(0, 0, 0, 0.18);
}
.dotgrid .label {
  font-size: 11px;
  color: var(--muted);
  margin-bottom: 6px;
}
.dotgrid .dots {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  max-width: 220px;
}
.dotgrid .dots i {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: linear-gradient(135deg, var(--p1), var(--p2));
  display: inline-block;
  animation: dotIn 0.35s var(--t) both;
}
.dotgrid.b .dots i {
  background: linear-gradient(135deg, var(--p3), var(--p1));
}
@keyframes dotIn {
  from {
    transform: scale(0);
  }
  to {
    transform: scale(1);
  }
}
.venn {
  position: relative;
  width: 280px;
  height: 160px;
  margin-top: 8px;
}
.venn .c {
  position: absolute;
  top: 10px;
  width: 160px;
  height: 140px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  font-weight: 800;
  font-size: 12px;
  color: #fff;
  opacity: 0.85;
  mix-blend-mode: screen;
}
.venn .c.a {
  left: 0;
  background: radial-gradient(
    circle at 35% 40%,
    rgba(124, 92, 255, 0.85),
    rgba(124, 92, 255, 0.15)
  );
}
.venn .c.b {
  left: 100px;
  background: radial-gradient(
    circle at 65% 40%,
    rgba(34, 211, 238, 0.85),
    rgba(34, 211, 238, 0.15)
  );
}
.venn .lbl {
  position: absolute;
  font-size: 11px;
  color: var(--muted);
}
canvas#confetti {
  position: fixed;
  inset: 0;
  z-index: 2000;
  pointer-events: none;
}
.toast {
  position: fixed;
  left: 50%;
  bottom: 24px;
  transform: translateX(-50%) translateY(20px);
  background: linear-gradient(135deg, var(--p1), var(--p2));
  color: #fff;
  font-weight: 700;
  padding: 10px 16px;
  border-radius: 999px;
  box-shadow: var(--shadow);
  opacity: 0;
  pointer-events: none;
  transition:
    opacity 0.3s var(--t),
    transform 0.3s var(--t);
  z-index: 10;
}
.toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}
.tips {
  font-size: 12px;
  color: var(--muted);
  margin-top: 10px;
  line-height: 1.55;
}
.tips b {
  color: var(--ink);
}
.kbd {
  font-family: ui-monospace, Menlo, monospace;
  font-size: 11px;
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid var(--stroke);
  padding: 2px 6px;
  border-radius: 6px;
  color: var(--muted);
}
.btn.hint-sm {
  padding: 6px 12px;
  font-size: 12px;
  border-radius: 10px;
}
.toggle {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  cursor: pointer;
  user-select: none;
}
.toggle input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}
.toggle .track {
  width: 40px;
  height: 22px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.12);
  border: 1px solid var(--stroke);
  position: relative;
  transition: background 0.2s var(--t);
}
.toggle .track::after {
  content: "";
  position: absolute;
  top: 2px;
  left: 2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #fff;
  transition: transform 0.2s var(--t);
}
.toggle input:checked + .track {
  background: linear-gradient(135deg, var(--p1), var(--p2));
}
.toggle input:checked + .track::after {
  transform: translateX(18px);
}
.toggle .lbl {
  font-weight: 700;
  font-size: 13px;
}

.year-scroll {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: thin;
}
.year-scroll::-webkit-scrollbar {
  height: 6px;
}
.year-scroll::-webkit-scrollbar-thumb {
  background: var(--stroke);
  border-radius: 3px;
}
.year-scroll .chip {
  flex: 0 0 auto;
  white-space: nowrap;
}
.dd {
  appearance: none;
  background: var(--glass);
  border: 1px solid var(--stroke);
  color: var(--ink);
  padding: 10px 32px 10px 14px;
  border-radius: 12px;
  font-weight: 600;
  font-size: 14px;
  cursor: pointer;
  min-width: 200px;
  background-image:
    linear-gradient(45deg, transparent 50%, var(--ink) 50%),
    linear-gradient(135deg, var(--ink) 50%, transparent 50%);
  background-position:
    calc(100% - 16px) 50%,
    calc(100% - 11px) 50%;
  background-size:
    5px 5px,
    5px 5px;
  background-repeat: no-repeat;
}
.dd option {
  background: #11173a;
  color: var(--ink);
}
.hide {
  display: none !important;
}
.flex {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  align-items: center;
}
.title-xl {
  font-size: 22px;
  margin: 0 0 4px;
  font-weight: 800;
  letter-spacing: 0.2px;
}
.muted {
  color: var(--muted);
  font-size: 13px;
  word-break: break-word;
  overflow-wrap: break-word;
  line-height: 1.5;
}
.divider {
  height: 1px;
  background: var(--stroke);
  margin: 12px 0;
}
.modal-overlay {
  position: fixed;
  inset: 0;
  z-index: 99;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(8px);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 18px;
  animation: fadeIn 0.3s var(--t);
}
.modal-overlay.hide {
  display: none;
}
@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}
.modal {
  background: linear-gradient(180deg, #141a3a, #0b1020);
  border: 1px solid var(--stroke);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  max-width: 720px;
  width: 100%;
  max-height: 90vh;
  display: flex;
  flex-direction: column;
  animation: modalSlide 0.35s var(--t);
}
@keyframes modalSlide {
  from {
    transform: translateY(30px) scale(0.97);
    opacity: 0;
  }
  to {
    transform: translateY(0) scale(1);
    opacity: 1;
  }
}
.modal-header {
  padding: 20px 22px 10px;
  border-bottom: 1px solid var(--stroke);
}
.modal-header h2 {
  margin: 0;
  font-size: 20px;
  font-weight: 800;
}
.modal-header p {
  margin: 4px 0 0;
  font-size: 13px;
}
.modal-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  padding: 12px 22px 0;
}
.modal-tab {
  appearance: none;
  border: none;
  background: var(--glass);
  color: var(--muted);
  padding: 8px 16px;
  border-radius: 999px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s var(--t);
  white-space: nowrap;
}
.modal-tab.active {
  background: linear-gradient(135deg, var(--p1), var(--p2));
  color: #fff;
  box-shadow: 0 4px 16px rgba(124, 92, 255, 0.35);
}
.modal-body {
  padding: 14px 22px 18px;
  overflow-y: auto;
  flex: 1;
  min-height: 200px;
}
.exam-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 8px;
}
@media (max-width: 520px) {
  .exam-grid {
    grid-template-columns: 1fr;
  }
}
@media (max-width: 520px) {
  .modal-footer {
    flex-wrap: wrap;
    gap: 8px;
    padding: 12px 16px;
    justify-content: center;
  }
  .modal-footer .toggle {
    width: 100%;
    justify-content: center;
  }
  .modal-footer > div:last-child {
    width: 100%;
    justify-content: center;
    gap: 8px;
  }
  .modal-footer .btn {
    flex: 1;
    min-width: 0;
    padding: 10px 12px;
    font-size: 13px;
  }
}
.exam-card {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  border-radius: 12px;
  border: 1px solid var(--stroke);
  background: var(--glass);
  transition: all 0.2s var(--t);
  user-select: none;
}
.exam-card:hover {
  border-color: var(--p2);
  background: rgba(34, 211, 238, 0.06);
}
.exam-card .el {
  flex: 1;
  font-weight: 600;
  font-size: 14px;
}
.modal-footer {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 14px 22px;
  border-top: 1px solid var(--stroke);
}
.modal-footer .btn {
  flex-shrink: 0;
}
.modal-tab.toggle {
  padding: 10px 18px;
  font-size: 13px;
  border: 2px solid transparent;
  transition: all 0.2s var(--t);
}
.modal-tab.toggle.active {
  border-color: var(--p2);
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.25),
    rgba(34, 211, 238, 0.15)
  );
  color: #fff;
}
.quick-picks {
  margin-top: 10px;
}
.quick-picks h4 {
  font-size: 12px;
  color: var(--muted);
  margin: 0 0 6px;
  font-weight: 600;
}
.quick-picks .qp-wrap {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  align-items: center;
}
.quick-picks .qp-chip {
  font-size: 11px;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px solid var(--stroke);
  white-space: nowrap;
  color: var(--muted);
}
.quick-picks .qp-more {
  font-size: 11px;
  padding: 4px 10px;
  border-radius: 999px;
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.2),
    rgba(34, 211, 238, 0.12)
  );
  border: 1px solid rgba(124, 92, 255, 0.3);
  color: var(--p2);
  cursor: pointer;
  white-space: nowrap;
  font-weight: 600;
}
.quick-picks .qp-more:hover {
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.4),
    rgba(34, 211, 238, 0.25)
  );
}
.qp-empty {
  font-size: 12px;
  color: var(--muted);
  font-style: italic;
}
#examTooltip {
  position: fixed;
  z-index: 100;
  background: linear-gradient(180deg, #141a3a, #0b1020);
  border: 1px solid var(--stroke);
  border-radius: 12px;
  padding: 10px 14px;
  box-shadow: var(--shadow);
  font-size: 12px;
  line-height: 1.8;
  min-width: 160px;
  max-width: 180px;
  display: none;
  pointer-events: auto;
}
#examTooltip.exam-tooltip-show {
  display: block;
}
#examTooltip .tt-label {
  color: var(--gold);
  font-weight: 700;
  font-size: 13px;
  margin-bottom: 4px;
  display: block;
}
#examTooltip .tt-name {
  color: var(--muted);
  display: block;
}
.exam-bar {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding: 6px 0 0;
  scrollbar-width: thin;
  align-items: center;
  min-height: 32px;
}
.exam-bar::-webkit-scrollbar {
  height: 4px;
}
.exam-bar::-webkit-scrollbar-thumb {
  background: var(--stroke);
  border-radius: 2px;
}
.exam-bar .exam-chip {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: 999px;
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.25),
    rgba(34, 211, 238, 0.15)
  );
  border: 1px solid rgba(124, 92, 255, 0.3);
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s var(--t);
  color: var(--ink);
}
.exam-bar .exam-chip:hover {
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.45),
    rgba(34, 211, 238, 0.3)
  );
  border-color: var(--p2);
}
.exam-bar .exam-chip .x {
  opacity: 0.5;
  margin-left: 2px;
  font-size: 13px;
  line-height: 1;
}
.exam-bar .exam-chip .x:hover {
  opacity: 1;
}
.exam-bar .exam-edit-btn {
  flex-shrink: 0;
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: 999px;
  background: var(--glass);
  border: 1px dashed var(--stroke);
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.2s var(--t);
  color: var(--muted);
}
.exam-bar .exam-edit-btn:hover {
  background: var(--glass-2);
  border-color: var(--p2);
  color: var(--ink);
}
.exam-bar-placeholder {
  font-size: 12px;
  color: var(--muted);
  cursor: pointer;
  padding: 4px 0;
}
.exam-bar-placeholder:hover {
  color: var(--p2);
}
.diff-filter-inline {
  display: none;
}
#typeSelect {
  display: none;
}
.diff-filter {
  display: flex;
  gap: 8px;
  margin-top: 10px;
  flex-wrap: wrap;
  align-items: center;
}
.tier-filter {
  display: flex;
  gap: 6px;
  flex-wrap: nowrap;
  align-items: center;
}
.tier-filter .diff-label {
  font-size: 12px;
  color: var(--muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  margin-right: 2px;
}
@media (max-width: 640px) {
  .bottom-row {
    flex-wrap: wrap;
    gap: 8px;
  }
  .tier-filter {
    margin-left: 0;
  }
}
.diff-filter .diff-label {
  font-size: 12px;
  color: var(--muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.4px;
  margin-right: 2px;
}
.diff-cb-wrap {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 10px;
  border-radius: 999px;
  white-space: nowrap;
  background: var(--glass);
  border: 1px solid var(--stroke);
  cursor: pointer;
  user-select: none;
  font-size: 13px;
  font-weight: 600;
  transition: all 0.2s var(--t);
}
.diff-cb-wrap:hover {
  border-color: var(--p2);
  background: rgba(34, 211, 238, 0.06);
}
.diff-cb-wrap input[type="checkbox"] {
  appearance: none;
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 4px;
  border: 2px solid var(--stroke);
  background: transparent;
  cursor: pointer;
  position: relative;
  transition: all 0.15s var(--t);
  flex-shrink: 0;
}
.diff-cb-wrap input[type="checkbox"]:checked {
  border-color: var(--p2);
  background: var(--p2);
}
.diff-cb-wrap input[type="checkbox"]:checked::after {
  content: "✓";
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 11px;
  font-weight: 800;
  color: #fff;
}
.diff-cb-wrap.easy input[type="checkbox"]:checked {
  border-color: #22c55e;
  background: #22c55e;
}
.diff-cb-wrap.medium input[type="checkbox"]:checked {
  border-color: #f59e0b;
  background: #f59e0b;
}
.diff-cb-wrap.hard input[type="checkbox"]:checked {
  border-color: #ef4444;
  background: #ef4444;
}
.diff-cb-wrap.disabled {
  opacity: 0.4;
  pointer-events: none;
}
.diff-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  display: inline-block;
  flex-shrink: 0;
}
.diff-dot.easy-dot {
  background: #22c55e;
  box-shadow: 0 0 8px rgba(34, 197, 94, 0.5);
}
.diff-dot.medium-dot {
  background: #f59e0b;
  box-shadow: 0 0 8px rgba(245, 158, 11, 0.5);
}
.diff-dot.hard-dot {
  background: #ef4444;
  box-shadow: 0 0 8px rgba(239, 68, 68, 0.5);
}

/* ══════════════════════════════���════════════════
   BOOK-FORMAT MATH NOTATION (KaTeX-powered)
   ═══════════════════════════════════════════════ */

/* --- Math expression wrapper --- */
.math {
  display: inline;
  white-space: nowrap;
  vertical-align: baseline;
}
.math .katex {
  font-size: 1.05em;
}

/* --- Math in question text: pill-shaped highlight like .num --- */
.q-text .math {
  display: inline-block;
  min-width: 1.2em;
  text-align: center;
  padding: 2px 10px;
  border-radius: 10px;
  background: linear-gradient(
    135deg,
    rgba(124, 92, 255, 0.35),
    rgba(34, 211, 238, 0.25)
  );
  border: 1px solid var(--stroke);
  margin: 0 3px;
  white-space: nowrap;
  vertical-align: baseline;
}
.q-text .math .katex {
  font-size: 1.2em;
}

/* --- Exponent / superscript (for unit superscripts like m², cm³) --- */
.sup {
  font-size: 0.7em;
  vertical-align: super;
  line-height: 0;
  padding-left: 1px;
}

/* --- Option labels (a), (b), (c), (d) --- */
.opt-label {
  font-weight: 700;
  font-size: 0.95em;
  margin-right: 6px;
  color: var(--p2);
  min-width: 1.6em;
  text-align: center;
}

/* --- Math inside options (no pill background) --- */
.opt .math .katex {
  font-size: 1.05em;
}

/* Force all option math (KaTeX fractions, etc.) into the sans font so every option matches */
.opt .katex,
.opt .katex * {
  font-family: inherit !important;
  font-style: normal !important;
}

/* Variant picker beside template tag */
.var-picker .tpl-picker-trigger {
  background: rgba(124, 92, 255, 0.1);
  border-color: rgba(124, 92, 255, 0.35);
  color: var(--ink);
}
.var-picker .tpl-picker-dropdown {
  min-width: 300px;
  max-width: 420px;
}
.tpl-picker-trigger .tpl-label {
  max-width: 170px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  display: inline-block;
}
@media (max-width: 520px) {
  .tpl-picker-trigger .tpl-label {
    max-width: 120px;
  }
  .var-picker .tpl-picker-dropdown {
    left: auto;
    right: 0;
    min-width: 280px;
  }
}

/* On phones/small tablets JS (fitPickerDropdown) anchors the open panel as a
   fixed element directly below its trigger and clamps it to the viewport. This
   block is only a fallback that prevents horizontal overflow before JS runs.
   Positioning is owned by JS so CSS can't fight it. */
@media (max-width: 820px) {
  .tpl-picker-dropdown {
    max-width: calc(100vw - 20px);
  }
  .tpl-picker-dropdown.open {
    z-index: 1000;
  }
}

@media (max-width: 520px) {
  .tagrow {
    max-width: 100%;
    overflow: visible;
  }
  .tpl-picker {
    min-width: 0;
    max-width: calc(50vw - 22px);
  }
  .tpl-picker-trigger {
    max-width: 100%;
    min-width: 0;
    overflow: hidden;
  }
  .tpl-picker-trigger .tpl-label {
    display: inline-block;
    max-width: calc(50vw - 74px);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .tpl-picker-dropdown {
    max-width: calc(100vw - 32px);
    width: calc(100vw - 32px);
    min-width: 0;
  }
  .tpl-item {
    min-width: 0;
  }
  .tpl-item .tpl-item-label {
    min-width: 0;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
  }
  .var-picker .tpl-list {
    max-height: 260px;
  }
}

/* ============================================================
   REQUEST 12b — ONE merged container (Setup/PYQ tabs + templates/questions)
   Section 1 = header (title + tier checkboxes). Section 2 = this single card.
   Desktop width ~800px centered; identical single-column layout on mobile (down to 375px).
   ============================================================ */
.grid {
  display: flex;
  flex-direction: column;
  gap: 0;
  max-width: 600px;
  margin: 0 auto;
}
.side { display: contents; }
#modeCard { order: 1; }
.q-card { order: 2; }

/* visually fuse the tabs card (top) and the play/list card (bottom) into one */
/* both halves share ONE flat background (no gradient seam) */
#modeCard {
  border-radius: var(--radius) var(--radius) 0 0;
  border-bottom: 1px solid var(--stroke); /* the single end-to-end divider */
  margin-bottom: 0;
  padding-bottom: 14px;
  box-shadow: none;
  background: var(--glass-2);
}
.q-card {
  border-radius: 0 0 var(--radius) var(--radius);
  border-top: none;
  margin-top: 0;
  padding-top: 14px;
  background: var(--glass-2);
}
.q-card::before { display: none !important; }

/* header bar matches the merged container width (800px, centered) */
header.top {
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

/* the seam border IS the divider now -> drop the inner duplicate line */
.pyq-divider { display: none !important; }

/* PYQ year chips: keep horizontal scroll action, hide the white scrollbar line */
.year-scroll {
  scrollbar-width: none;
  -ms-overflow-style: none;
  padding-bottom: 0;
}
.year-scroll::-webkit-scrollbar { height: 0; width: 0; display: none; }

/* breathing room between the year chips and the count text */
#pyqStatus { margin-top: 12px; }

/* exam dropdown matches the language selector's compact UI (size/shape) */
#pyqExamSelect {
  min-width: 0;
  width: auto;
  padding: 6px 24px 6px 10px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 400;
  background-position: calc(100% - 12px) 50%, calc(100% - 7px) 50%;
  background-size: 4px 4px, 4px 4px;
}

/* Question Setup tab only: shift the seam divider up ~24px (tighter gap under the tabs) */
body:not(.pyq-active) .capsule-tabs { margin-bottom: 4px; }
body:not(.pyq-active) #modeCard { padding-bottom: 2px; }

/* ---- Apple-style micro-bounce on interactions (whole MCQ page + subpages) ---- */
button, .opt, .chip, .capsule-tab, .pon-li, .pon-li-chev, .backbtn,
.dd, .q-lang-select, .tpl-picker-trigger, .vx-btn, .diff-cb-wrap, .tpl-item {
  transition:
    transform var(--spring-dur, .55s) var(--spring, cubic-bezier(.34, 1.56, .64, 1)),
    background-color .18s ease,
    border-color .18s ease,
    color .18s ease,
    box-shadow .2s ease,
    opacity .18s ease !important;
}
button:active, .opt:active, .chip:active, .capsule-tab:active, .pon-li:active,
.pon-li-chev:active, .backbtn:active, .dd:active, .q-lang-select:active,
.tpl-picker-trigger:active, .vx-btn:active, .diff-cb-wrap:active, .tpl-item:active {
  /* press feedback now handled by bounce.js (compress + spring-back); keep neutral */
  transform: none;
}
@media (prefers-reduced-motion: reduce) {
  button, .opt, .chip, .capsule-tab, .pon-li, .pon-li-chev, .backbtn,
  .dd, .q-lang-select, .tpl-picker-trigger, .vx-btn, .diff-cb-wrap, .tpl-item {
    transition: none !important;
  }
}

/* --- real spring easing (anime.js default: mass 1, stiffness 100, damping 10) --- */
:root{
  /* anime.js spring({ bounce: 0.31, duration: 500 }) -- exact generated curve (peak 1.05 = 5% overshoot) */
  --spring: linear(0, 0.0086, 0.0324, 0.0684, 0.1138, 0.1664, 0.2239, 0.2847, 0.347, 0.4097, 0.4715, 0.5317, 0.5894, 0.6442, 0.6956, 0.7433, 0.7871, 0.8271, 0.8631, 0.8953, 0.9237, 0.9485, 0.97, 0.9883, 1.0037, 1.0164, 1.0266, 1.0347, 1.0408, 1.0451, 1.048, 1.0496, 1.05, 1.0496, 1.0484, 1.0466, 1.0443, 1.0417, 1.0388, 1.0357, 1.0326, 1.0295, 1.0264, 1.0234, 1.0205, 1.0178, 1.0152, 1.0128, 1.0106, 1.0086, 1.0068, 1.0052, 1.0038, 1.0026, 1.0015, 1.0006, 0.9998, 0.9992, 0.9987, 0.9983, 0.998, 0.9977, 0.9976, 0.9975, 0.9975, 0.9975, 0.9976, 0.9977, 0.9978, 0.9979, 0.9981, 0.9982, 0.9984, 0.9985, 0.9987, 0.9988, 0.999, 0.9991, 0.9992, 0.9994, 0.9995, 0.9996, 0.9997, 0.9997, 0.9998, 0.9999, 0.9999, 1, 1, 1, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1.0001, 1);
  --spring-dur: .2s;
}
/* apply the spring to the sliding drawer + variant solution height too */
/* (removed) drawer transition is owned by ux.css now -- asymmetric M3 emphasized
   (smooth decelerate open / quick accelerate close). The old spring !important here
   was overriding it and reintroducing the bouncy overshoot on the mobile drawer. */

/* ====== one-shot interaction feedback (JS-triggered via bounce.js, visible on every tap) ====== */
:root{ --pop-dur: .15s; }

/* SCALE pop -> buttons, options, checkbox, chips, etc: grow a touch then spring back to exact size */
@keyframes popBounce{
  0%   { transform: scale(1); }
  35%  { transform: scale(var(--pop-up, 1.01)); }   /* grow a touch */
  70%  { transform: scale(var(--pop-down, .997)); } /* dip just below real size */
  100% { transform: scale(1); }                     /* settle smoothly to exact size */
}
.pop-anim{ --pop-up: 1.01; --pop-down: .997; animation: popBounce var(--pop-dur, .15s) ease-out; }
/* checkbox feels right as-is -> keep its slightly larger pop */
.diff-cb-wrap.pop-anim{ --pop-up: 1.024; --pop-down: .993; }

/* ===== research-backed press feedback (Apple HIG/SwiftUI, Material 3, Airbnb, Instagram):
   COMPRESS on press -> SPRING BACK to exact size. One-shot keyframe fired on pointerdown,
   so it plays fully on every tap (CSS animations override transitions + :active reliably). */
@keyframes bxPress{
  0%   { transform: scale(1);   animation-timing-function: cubic-bezier(.4, 0, .2, 1); }
  38%  { transform: scale(.94); animation-timing-function: cubic-bezier(.34, 1.56, .64, 1); }
  100% { transform: scale(1); }
}
.bx-anim{ animation: bxPress .30s both; }
@media (prefers-reduced-motion: reduce){
  .bx-anim{ animation: none !important; }
}
/* ===== vertical scrollbar policy (mobile/iPad vs desktop) =====
   Mobile + iPad (<=1024px): NO scrollbars anywhere (swipe to scroll); no gutter reserved so
   nothing shifts. Desktop only (>=1025px): show a DARK, theme-matched page scrollbar and keep
   the gutter reserved so switching Setup <-> PYQ never shifts the page/header horizontally. */
/* ===== vertical scrollbar policy (mobile/iPad vs desktop) =====
   Default = hidden (mobile-first). Desktop (>=1025px) re-enables ONE dark scrollbar.
   The page actually scrolls on <body> (body has overflow-x:hidden), so we target
   html, body AND :root to be certain the viewport scrollbar is reached. */
html, body, :root{ scrollbar-width: none; -ms-overflow-style: none; }
html::-webkit-scrollbar, body::-webkit-scrollbar{ width: 0; height: 0; display: none; }

/* mobile + iPad (<=1024px): NO scrollbars ANYWHERE -- swipe to scroll */
@media (max-width: 1024px){
  html, body, :root{ scrollbar-width: none !important; }
  html::-webkit-scrollbar, body::-webkit-scrollbar, *::-webkit-scrollbar{
    width: 0 !important; height: 0 !important; display: none !important;
  }
}

/* desktop only (>=1025px): ONE DARK, theme-matched scrollbar + reserved gutter.
   Standard scrollbar-color/-width (Chrome 121+, Firefox, Edge) is the primary path and is
   FORCED with !important on html/body/:root so the propagated VIEWPORT scrollbar turns dark
   (this is what fixes the white bar in PYQ). webkit pseudo is a fallback for older Safari.
   Inner scrollers (.pon-db, .tpl-list) keep their own more-specific (non-!important) styles. */
@media (min-width: 1025px){
  html, body, :root{
    scrollbar-gutter: stable;
    scrollbar-width: thin !important;
    scrollbar-color: #2b3760 #0a0e1c !important;     /* thumb (visible dark) / track (near-black) */
  }
  ::-webkit-scrollbar{ width: 12px; height: 12px; }
  html::-webkit-scrollbar, body::-webkit-scrollbar{ width: 12px; height: 12px; display: block; }
  html::-webkit-scrollbar-track, body::-webkit-scrollbar-track{ background: #0a0e1c; }
  html::-webkit-scrollbar-thumb, body::-webkit-scrollbar-thumb{
    background: #2b3760;
    border-radius: 8px;
    border: 3px solid #0a0e1c;
  }
  html::-webkit-scrollbar-thumb:hover, body::-webkit-scrollbar-thumb:hover{ background: #3a4878; }
}

/* POSITION bounce -> capsule tabs (Question Setup / PYQ): slide in from its side + settle */
@keyframes tabPopL{
  0%   { transform: translateX(-12px); }
  62%  { transform: translateX(3px); }
  100% { transform: translateX(0); }
}
@keyframes tabPopR{
  0%   { transform: translateX(12px); }
  62%  { transform: translateX(-3px); }
  100% { transform: translateX(0); }
}
.capsule-tab.tab-pop-l{ animation: tabPopL .3s cubic-bezier(.34,1.4,.5,1); }
.capsule-tab.tab-pop-r{ animation: tabPopR .3s cubic-bezier(.34,1.4,.5,1); }

/* hint / answer feedback reveal (position-based pop) */
@keyframes fbPop{
  0%   { opacity:0; transform: translateY(6px) scale(.99); }
  60%  { opacity:1; transform: translateY(0) scale(1.012); }
  100% { transform: translateY(0) scale(1); }
}
.feedback.hint, .feedback.ok, .feedback.bad{ animation: fbPop .36s cubic-bezier(.34,1.56,.64,1); }

@media (prefers-reduced-motion: reduce){
  .pop-anim, .capsule-tab.tab-pop-l, .capsule-tab.tab-pop-r,
  .feedback.hint, .feedback.ok, .feedback.bad{ animation: none !important; }
}