:root {
  --ink: #101827;
  --muted: #697386;
  --paper: #fffaf2;
  --panel: rgba(255, 255, 255, .9);
  --panel-strong: #ffffff;
  --line: rgba(91, 31, 77, .13);
  --sun: #ffd411;
  --gold: #ffb317;
  --orange: #f47b20;
  --coral: #d8513f;
  --plum: #5b1f4d;
  --plum-dark: #351431;
  --ok: #138a4b;
  --bad: #c0362c;
  --shadow: 0 18px 50px rgba(53, 20, 49, .12);
  --soft-shadow: 0 10px 28px rgba(53, 20, 49, .1);
}

* {
  box-sizing: border-box;
  user-select: none;
  -webkit-user-select: none;
}

html {
  scroll-behavior: smooth;
}

body {
  --scope-x: 50vw;
  --scope-y: 50vh;
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background:
    radial-gradient(circle at 18% 6%, rgba(255, 212, 17, .38), transparent 28rem),
    radial-gradient(circle at 92% 10%, rgba(244, 123, 32, .28), transparent 26rem),
    linear-gradient(135deg, #fff7dd 0%, #fffaf2 42%, #f9edf1 100%);
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, Helvetica, sans-serif;
  line-height: 1.5;
  overflow-x: hidden;
}

body.sniper-mode,
body.sniper-mode * {
  cursor: none !important;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    linear-gradient(118deg, rgba(255, 212, 17, .9) 0 18%, transparent 18.2%),
    linear-gradient(145deg, transparent 0 32%, rgba(244, 123, 32, .16) 32.2% 52%, transparent 52.2%),
    linear-gradient(28deg, transparent 0 67%, rgba(91, 31, 77, .12) 67.2% 100%);
  clip-path: polygon(0 0, 100% 0, 100% 58%, 0 74%);
  pointer-events: none;
}

body::after {
  content: "";
  position: fixed;
  inset: auto -12vw 0 -12vw;
  z-index: -1;
  height: 34vh;
  background: linear-gradient(100deg, rgba(91, 31, 77, .92), rgba(216, 81, 63, .74), rgba(244, 123, 32, .35));
  clip-path: polygon(0 36%, 36% 16%, 68% 42%, 100% 0, 100% 100%, 0 100%);
  opacity: .08;
  pointer-events: none;
}

.page-intro,
main {
  width: min(1120px, calc(100% - 32px));
  margin: 0 auto;
}

.page-intro {
  position: relative;
  margin-top: 26px;
  margin-bottom: 18px;
  padding: 22px 24px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .58);
  border-radius: 24px;
  background:
    linear-gradient(120deg, rgba(255, 212, 17, .98), rgba(255, 179, 23, .94) 38%, rgba(244, 123, 32, .92) 68%, rgba(91, 31, 77, .88)),
    var(--gold);
  box-shadow: var(--shadow);
  animation: introIn .55s ease both;
}

.page-intro::before,
.page-intro::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
}

.page-intro::before {
  background:
    linear-gradient(135deg, rgba(255, 255, 255, .18) 0 16%, transparent 16.2%),
    linear-gradient(27deg, transparent 0 54%, rgba(255, 255, 255, .14) 54.2% 64%, transparent 64.2%),
    linear-gradient(155deg, transparent 0 62%, rgba(91, 31, 77, .22) 62.2% 100%);
}

.page-intro::after {
  width: 220px;
  height: 220px;
  inset: auto -54px -116px auto;
  border-radius: 999px;
  background: rgba(255, 255, 255, .18);
  filter: blur(2px);
}

.subtitle {
  position: relative;
  z-index: 1;
  max-width: 780px;
  margin: 0;
  color: #ffffff;
  font-size: clamp(17px, 2vw, 22px);
  font-weight: 750;
  letter-spacing: .01em;
  text-shadow: 0 2px 16px rgba(53, 20, 49, .18);
}

.year-switcher {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.year-button {
  min-width: 92px;
  color: var(--plum-dark);
  background: rgba(255, 255, 255, .88);
  box-shadow: 0 10px 24px rgba(53, 20, 49, .14);
}

.year-button.active {
  color: #fff;
  background: linear-gradient(135deg, var(--plum), var(--coral));
}

.tasks {
  display: grid;
  gap: 16px;
}

.task {
  position: relative;
  overflow: hidden;
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, .96), rgba(255, 255, 255, .88)),
    var(--panel-strong);
  box-shadow: var(--soft-shadow);
  transform: translateY(0);
  transition:
    transform .28s ease,
    box-shadow .28s ease,
    border-color .28s ease,
    background-color .28s ease;
  animation: cardIn .45s ease both;
}

.task:nth-child(2n) {
  animation-delay: .025s;
}

.task:nth-child(3n) {
  animation-delay: .05s;
}

.task:hover {
  transform: translateY(-3px);
  border-color: rgba(244, 123, 32, .32);
  box-shadow: 0 22px 58px rgba(53, 20, 49, .16);
}

.task::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 5px;
  background: linear-gradient(180deg, var(--sun), var(--orange), var(--plum));
  opacity: .95;
}

.task-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  padding: 0 0 13px 8px;
  border-bottom: 1px solid rgba(105, 115, 134, .16);
}

h3 {
  margin: 0;
  font-size: 18px;
  font-weight: 850;
  letter-spacing: .01em;
}

.points {
  flex: none;
  padding: 6px 10px;
  border-radius: 999px;
  color: var(--plum-dark);
  background: linear-gradient(135deg, rgba(255, 212, 17, .45), rgba(255, 179, 23, .2));
  font-size: 13px;
  font-weight: 850;
}

.prompt {
  margin: 16px 0 10px;
  padding-left: 8px;
  font-size: 17px;
  font-weight: 760;
}

.hint {
  margin: 0 0 14px;
  padding-left: 8px;
  color: var(--muted);
  font-size: 14px;
}

.task-figure,
.figure {
  margin: 14px 0 16px 8px;
  padding: 14px;
  border: 1px solid rgba(91, 31, 77, .12);
  border-radius: 16px;
  background: linear-gradient(135deg, rgba(255, 250, 242, .9), rgba(255, 255, 255, .95));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .75);
}

.task-figure img {
  display: block;
  max-width: min(100%, 720px);
  max-height: 360px;
  margin: 0 auto;
  object-fit: contain;
  border-radius: 12px;
}

.truth-table,
.selector-table {
  border-collapse: separate;
  border-spacing: 0;
  min-width: 260px;
  overflow: hidden;
  border: 1px solid rgba(91, 31, 77, .18);
  border-radius: 12px;
}

.truth-table th,
.truth-table td,
.selector-table th,
.selector-table td {
  padding: 8px 14px;
  border-right: 1px solid rgba(91, 31, 77, .14);
  border-bottom: 1px solid rgba(91, 31, 77, .14);
  text-align: center;
}

.truth-table th,
.selector-table th {
  background: rgba(255, 179, 23, .22);
}

.truth-table tr:last-child td,
.selector-table tr:last-child td {
  border-bottom: 0;
}

.truth-table td:last-child,
.truth-table th:last-child,
.selector-table td:last-child,
.selector-table th:last-child {
  border-right: 0;
}

.options {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.option label {
  display: grid;
  grid-template-columns: auto 1fr;
  align-items: start;
  gap: 10px;
  min-height: 46px;
  padding: 11px 12px;
  border: 1px solid rgba(105, 115, 134, .18);
  border-radius: 14px;
  color: var(--ink);
  background: rgba(255, 255, 255, .82);
  cursor: pointer;
  transition:
    transform .2s ease,
    border-color .2s ease,
    background .2s ease,
    box-shadow .2s ease;
}

.option label:hover {
  transform: translateX(4px);
  border-color: rgba(244, 123, 32, .45);
  background: #fff;
  box-shadow: 0 10px 24px rgba(244, 123, 32, .12);
}

.option:has(input:checked) label {
  border-color: rgba(244, 123, 32, .72);
  background: linear-gradient(135deg, rgba(255, 212, 17, .22), rgba(244, 123, 32, .1));
  box-shadow: 0 10px 26px rgba(244, 123, 32, .13);
}

.option input {
  width: 18px;
  height: 18px;
  margin: 2px 0 0;
  accent-color: var(--orange);
}

.match-list {
  display: grid;
  gap: 12px;
  margin-top: 14px;
}

.match-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 1px solid rgba(105, 115, 134, .18);
  border-radius: 14px;
  background: rgba(255, 255, 255, .78);
}

.match-text {
  font-weight: 650;
}

.match-choices {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  justify-content: flex-end;
}

.match-choice input {
  position: absolute;
  opacity: 0;
  pointer-events: none;
}

.match-choice span {
  display: inline-grid;
  min-width: 48px;
  min-height: 34px;
  place-items: center;
  border: 1px solid rgba(91, 31, 77, .18);
  border-radius: 999px;
  background: #fff;
  color: var(--plum-dark);
  font-weight: 850;
  cursor: pointer;
  transition: transform .2s ease, border-color .2s ease, background .2s ease, color .2s ease;
}

.match-choice span:hover {
  transform: translateY(-1px);
  border-color: rgba(244, 123, 32, .52);
}

.match-choice input:checked + span {
  color: #fff;
  border-color: transparent;
  background: linear-gradient(135deg, var(--orange), var(--plum));
}

.letter {
  color: var(--plum);
  font-weight: 850;
}

.solution,
.feedback {
  display: none;
  margin: 14px 0 0 8px;
  padding: 11px 12px;
  border-radius: 14px;
  font-weight: 760;
  animation: feedbackIn .22s ease both;
}

.solution {
  border: 1px solid rgba(91, 31, 77, .18);
  color: var(--plum-dark);
  background: rgba(255, 179, 23, .13);
}

.feedback.correct {
  display: block;
  color: var(--ok);
  background: rgba(19, 138, 75, .09);
}

.feedback.wrong {
  display: block;
  color: var(--bad);
  background: rgba(192, 54, 44, .09);
}

.toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  margin: 24px 0 34px;
  padding: 12px;
  border: 1px solid rgba(255, 255, 255, .7);
  border-radius: 20px;
  background: rgba(255, 255, 255, .78);
  box-shadow: var(--shadow);
  backdrop-filter: blur(16px);
}

button {
  min-height: 44px;
  border: 0;
  border-radius: 999px;
  padding: 10px 18px;
  color: #fff;
  background: linear-gradient(135deg, var(--orange), var(--coral), var(--plum));
  font: inherit;
  font-weight: 850;
  cursor: pointer;
  box-shadow: 0 12px 28px rgba(216, 81, 63, .28);
  transition:
    transform .2s ease,
    box-shadow .2s ease,
    filter .2s ease;
}

button:hover {
  transform: translateY(-2px);
  box-shadow: 0 16px 34px rgba(216, 81, 63, .34);
  filter: saturate(1.08);
}

button:active {
  transform: translateY(0) scale(.98);
}

output {
  margin-right: auto;
  padding: 9px 14px;
  border-radius: 999px;
  color: #fff;
  background: var(--plum);
  font-weight: 900;
  box-shadow: 0 10px 24px rgba(91, 31, 77, .22);
}

.sniper-overlay {
  position: fixed;
  inset: 0;
  z-index: 9999;
  opacity: 0;
  pointer-events: none;
  background: radial-gradient(
    circle 182px at var(--scope-x) var(--scope-y),
    transparent 0 174px,
    rgba(0, 0, 0, .96) 178px,
    #000 100%
  );
  transition: opacity .24s ease;
}

body.sniper-mode .sniper-overlay {
  opacity: 1;
}

.sniper-scope {
  position: fixed;
  left: var(--scope-x);
  top: var(--scope-y);
  width: 360px;
  height: 360px;
  border: 1px solid rgba(0, 0, 0, .96);
  border-radius: 50%;
  background:
    radial-gradient(circle, rgba(255, 255, 255, .96) 0 2px, transparent 3px),
    linear-gradient(90deg, transparent 0 calc(50% - .5px), rgba(0, 0, 0, .96) calc(50% - .5px) calc(50% + .5px), transparent calc(50% + .5px)),
    linear-gradient(0deg, transparent 0 calc(50% - .5px), rgba(0, 0, 0, .96) calc(50% - .5px) calc(50% + .5px), transparent calc(50% + .5px));
  box-shadow:
    0 0 0 1px rgba(255, 255, 255, .38),
    0 0 32px rgba(255, 255, 255, .18),
    inset 0 0 0 10px rgba(0, 0, 0, .07),
    inset 0 0 42px rgba(0, 0, 0, .18);
  transform: translate(-50%, -50%);
  transition: width .16s ease, height .16s ease, box-shadow .16s ease;
}

.sniper-reload {
  position: fixed;
  left: var(--scope-x);
  top: calc(var(--scope-y) + 204px);
  width: 220px;
  height: 7px;
  overflow: hidden;
  border: 1px solid rgba(255, 255, 255, .9);
  border-radius: 999px;
  background: rgba(255, 255, 255, .16);
  box-shadow: 0 0 18px rgba(255, 255, 255, .3);
  opacity: 0;
  transform: translateX(-50%);
  transition: opacity .18s ease;
}

.sniper-reload span {
  display: block;
  width: 100%;
  height: 100%;
  background: #fff;
  transform: scaleX(0);
  transform-origin: left center;
}

body.sniper-reloading .sniper-reload {
  opacity: 1;
}

body.sniper-reloading .sniper-reload span {
  animation: sniperReload 1.8s linear both;
}

.sniper-scope::before,
.sniper-scope::after {
  content: "";
  position: absolute;
  inset: 50% auto auto 50%;
  width: 44px;
  height: 44px;
  border: 1px solid rgba(0, 0, 0, .82);
  border-radius: 50%;
  transform: translate(-50%, -50%);
}

.sniper-scope::after {
  width: 144px;
  height: 144px;
  border-color: rgba(0, 0, 0, .36);
}

body.sniper-shot .sniper-scope {
  width: 342px;
  height: 342px;
  box-shadow:
    0 0 0 1px rgba(0, 0, 0, .5),
    0 0 44px rgba(255, 212, 17, .42),
    inset 0 0 0 12px rgba(0, 0, 0, .2),
    inset 0 0 54px rgba(255, 179, 23, .28);
}

body.sniper-shot .sniper-overlay::after {
  content: "";
  position: fixed;
  inset: 0;
  background: rgba(255, 244, 190, .2);
  animation: muzzleFlash .18s ease both;
}

body.sniper-shot .page-intro,
body.sniper-shot main {
  animation: sniperShake .32s cubic-bezier(.2, .8, .2, 1) both;
}

@keyframes muzzleFlash {
  from {
    opacity: .9;
  }
  to {
    opacity: 0;
  }
}

@keyframes sniperShake {
  0% {
    transform: translate(0, 0) rotate(0);
  }
  18% {
    transform: translate(-12px, 7px) rotate(-.45deg);
  }
  36% {
    transform: translate(10px, -5px) rotate(.38deg);
  }
  54% {
    transform: translate(-7px, 3px) rotate(-.28deg);
  }
  72% {
    transform: translate(4px, -2px) rotate(.16deg);
  }
  100% {
    transform: translate(0, 0) rotate(0);
  }
}

@keyframes sniperReload {
  from {
    transform: scaleX(0);
  }
  to {
    transform: scaleX(1);
  }
}

@keyframes introIn {
  from {
    opacity: 0;
    transform: translateY(-12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes cardIn {
  from {
    opacity: 0;
    transform: translateY(14px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes feedbackIn {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@media (max-width: 760px) {
  .page-intro,
  main {
    width: min(100% - 20px, 1120px);
  }

  .page-intro {
    margin-top: 14px;
    border-radius: 18px;
  }

  .task {
    padding: 16px;
    border-radius: 16px;
  }

  .task-header {
    display: grid;
    padding-left: 6px;
  }

  .prompt,
  .hint,
  .task-figure,
  .figure,
  .solution,
  .feedback {
    margin-left: 0;
    padding-left: 0;
  }

  .toolbar {
    justify-content: stretch;
  }

  output {
    width: 100%;
    margin-right: 0;
    text-align: center;
  }

  button {
    flex: 1 1 140px;
  }
}

@media print {
  html {
    scroll-behavior: auto;
  }

  body {
    background: #fff;
    font-size: 11pt;
  }

  body::before,
  body::after {
    display: none;
  }

  .page-intro,
  main {
    width: 100%;
  }

  .page-intro {
    padding: 0 0 12px;
    border: 0;
    background: none;
    box-shadow: none;
  }

  .subtitle {
    color: #555;
    text-shadow: none;
  }

  .toolbar {
    display: none;
  }

  .task {
    break-inside: avoid;
    margin-bottom: 10px;
    border-color: #888;
    box-shadow: none;
  }

  .solution,
  .feedback {
    display: none !important;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}