:root {
  --black: #2f3a40;
  --gray: #7b858b;
  --white: #ffffff;
  --sky: #8fd3f4;
  --sky-soft: #e5f6fd;
  --sky-deep: #43a9d8;
  --line: #d9e8ed;
  --muted-bg: #f8fbfc;

  --correct: #e85050;
  --correct-soft: #fff2f2;
  --wrong: var(--sky-deep);
  --wrong-soft: var(--sky-soft);

  --font-body: "Noto Sans JP", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-display: "Noto Sans JP", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --font-small: 1rem;
  --font-base: 1.1rem;
  --font-large: 3rem;

  --radius-none: 0;
  --radius-base: 5px;
  --radius-pill: 999px;

  --shadow-comment: 0 4px 12px rgba(76, 112, 128, 0.07);
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 28px 12px 70px;
  font-family: var(--font-body);
  font-size: var(--font-base);
  font-optical-sizing: auto;
  font-weight: 500;
  line-height: 1.8;
  color: var(--black);
  background: var(--white);
}

.experiment-container {
  position: relative;
  width: min(920px, 100%);
  margin: 0 auto;
  padding: 26px;
  overflow: hidden;
  background: var(--white);
}

.page {
  display: none;
}

.page.active {
  display: block;
}

.hidden {
  display: none !important;
}

.progress-bar {
  width: 100%;
  height: 8px;
  margin-bottom: 26px;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-none);
  background: var(--sky-soft);
}

#progress-inner {
  width: 0;
  height: 100%;
  transition: width 0.25s ease;
  background: var(--sky-deep);
}

h1,
h2,
h3,
p {
  margin-top: 0;
}

h1 {
  margin: 8px 0 18px;
  font-family: var(--font-display);
  font-size: var(--font-large);
  font-weight: 400;
  letter-spacing: 0.05em;
  line-height: 1.35;
  text-align: center;
}

h1::before {
  content: "-COMMENT QUIZ-";
  display: block;
  margin-bottom: 8px;
  font-family: var(--font-body);
  font-size: var(--font-small);
  font-weight: 800;
  letter-spacing: 0.16em;
  color: var(--sky-deep);
}

h2,
h3 {
  font-size: var(--font-base);
  line-height: 1.5;
}

h2 {
  margin: 8px 0 16px;
  font-weight: 800;
  text-align: center;
}

h3 {
  margin: 32px 0 12px;
  font-weight: 800;
}

.sub-comment,
.article-box,
.comment-card,
.feedback-box.correct,
.feedback-box.wrong,
.result-item {
  border: 1px solid var(--line);
  border-radius: var(--radius-base);
}

.sub-comment,
.article-box {
  width: min(820px, 100%);
  margin: 20px auto;
  padding: 20px;
  background: var(--sky-soft);
}

.sub-comment {
  text-align: center;
}


.mode-select {
  width: min(820px, 100%);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin: 18px auto 4px;
}

.mode-card {
  min-height: 150px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 10px;
  padding: 18px 16px;
  background: var(--white);
  color: var(--black);
  text-align: center;
}

.mode-card.selected {
  border-color: var(--sky-deep);
  background: var(--sky-soft);
}

.mode-card.selected::before {
  content: "選択中";
  width: fit-content;
  margin: 0 auto;
  padding: 2px 9px;
  border-radius: var(--radius-pill);
  background: var(--white);
  color: var(--sky-deep);
  font-size: var(--font-small);
  font-weight: 800;
}

.mode-label {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(1.9rem, 5vw, 3rem);
  font-weight: 400;
  line-height: 1.2;
  letter-spacing: 0.04em;
}

.mode-desc {
  display: block;
  color: var(--gray);
  font-size: var(--font-small);
  font-weight: 700;
  line-height: 1.65;
}

.article-box {
  position: relative;
  text-align: left;
  white-space: pre-wrap;
  overflow: hidden;
}

.article-box::before {
  content: "NEWS";
  display: inline-block;
  margin-bottom: 12px;
  padding: 4px 10px;
  border-radius: var(--radius-base);
  background: var(--white);
  color: var(--sky-deep);
  font-size: var(--font-small);
  font-weight: 800;
  letter-spacing: 0.1em;
}

.comment-card {
  width: min(820px, 100%);
  margin: 20px auto;
  padding: 18px 16px;
  background: var(--white);
  box-shadow: var(--shadow-comment);
  white-space: pre-wrap;
}

.comment-card.correct-flash {
  animation: correctCard 0.52s ease both;
}

.comment-card.wrong-flash {
  animation: wrongCard 0.52s ease both;
}

.small-label {
  margin: 0 0 8px;
  color: var(--sky-deep);
  font-size: var(--font-small);
  font-weight: 800;
  text-align: center;
}

.key-guide,
.keyboard-hint {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 10px;
  margin-top: 14px;
  color: var(--gray);
  font-size: var(--font-small);
  font-weight: 700;
}

.keyboard-hint {
  margin: 12px 0 4px;
}

kbd {
  display: inline-block;
  min-width: 2.25em;
  padding: 3px 8px;
  margin-right: 4px;
  border: 1px solid var(--line);
  border-bottom-width: 3px;
  border-radius: var(--radius-base);
  background: var(--white);
  color: var(--black);
  font-family: var(--font-mono);
  font-size: 0.9em;
  font-weight: 800;
  text-align: center;
}

button,
.primary-btn,
.answer-btn,
.mode-card {
  border: 1px solid var(--line);
  border-radius: var(--radius-base);
  font: inherit;
  font-size: var(--font-base);
  font-weight: 800;
  cursor: pointer;
  transition: opacity 0.15s ease, transform 0.08s ease, border-color 0.15s ease, background 0.15s ease;
}

button:hover,
.primary-btn:hover,
.answer-btn:hover,
.mode-card:hover {
  opacity: 0.94;
}

button:active,
.primary-btn:active,
.answer-btn:active,
.mode-card:active {
  transform: translateY(1px);
}

button:disabled,
.answer-btn:disabled,
.mode-card:disabled {
  cursor: default;
  opacity: 1;
}

.primary-btn {
  display: block;
  width: min(420px, 100%);
  padding: 14px 16px;
  margin: 18px auto 0;
  background: var(--sky-deep);
  color: var(--white);
}

.quiz-options {
  width: min(820px, 100%);
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
  margin: 18px auto;
}

.answer-btn {
  min-height: 64px;
  padding: 14px 16px;
  background: var(--white);
  color: var(--black);
}

.answer-btn.selected {
  border-color: var(--sky-deep);
  background: var(--sky-soft);
}

.answer-btn.correct-choice {
  border-color: var(--correct);
  background: var(--correct);
  color: var(--white);
}

.answer-btn.wrong-choice {
  border-color: var(--wrong);
  background: var(--wrong);
  color: var(--white);
}

.feedback-box {
  width: min(820px, 100%);
  min-height: 0;
  margin: 16px auto;
  padding: 0;
}

.feedback-box.correct,
.feedback-box.wrong {
  padding: 18px;
  box-shadow: var(--shadow-comment);
  text-align: center;
}

.feedback-box.correct {
  border-color: color-mix(in srgb, var(--correct) 45%, var(--line));
  background: var(--correct-soft);
}

.feedback-box.wrong {
  border-color: var(--wrong);
  background: var(--wrong-soft);
}

.feedback-main {
  display: inline-block;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 6vw, 4rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 1.25;
}

.feedback-box.correct .feedback-main {
  color: var(--correct);
  animation: popText 0.4s cubic-bezier(.18, .89, .32, 1.28) both;
}

.feedback-box.wrong .feedback-main {
  color: var(--wrong);
  animation: shakeText 0.45s ease both;
}

.feedback-explanation,
.result-explanation,
.next-hint {
  display: inline-block;
  margin-top: 8px;
  color: var(--gray);
  font-size: var(--font-small);
  font-weight: 700;
}

.effect-overlay {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 999;
  display: grid;
  place-items: center;
  opacity: 0;
}

.effect-overlay.show {
  opacity: 1;
}

.effect-burst {
  position: relative;
  display: inline-grid;
  place-items: center;
  width: min(72vw, 400px);
  aspect-ratio: 1 / 1;
  border: 1px solid currentColor;
  border-radius: var(--radius-pill);
  background: rgba(255, 255, 255, 0.94);
  font-family: var(--font-display);
  font-size: clamp(3.2rem, 12vw, 6.8rem);
  line-height: 1;
  text-align: center;
  box-shadow: var(--shadow-comment);
}

.effect-burst::before,
.effect-burst::after {
  content: "";
  position: absolute;
  inset: -20px;
  border: 1px dashed currentColor;
  border-radius: var(--radius-pill);
}

.effect-burst.correct {
  color: var(--correct);
  animation: pinponBurst 0.8s ease both;
}

.effect-burst.wrong {
  color: var(--wrong);
  animation: batsuBurst 0.8s ease both;
}

.effect-burst.correct::before,
.effect-burst.correct::after,
.effect-burst.wrong::before,
.effect-burst.wrong::after {
  animation: ringOut 0.8s ease both;
}

.effect-burst::after {
  animation-delay: 0.08s;
}

.score-text {
  margin: 18px 0 6px;
  font-family: var(--font-display);
  font-size: clamp(2.1rem, 6vw, 4rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 1.35;
  text-align: center;
}

.score-sub-text {
  margin: 0 0 24px;
  color: var(--gray);
  font-weight: 700;
  text-align: center;
}

.result-list {
  width: min(820px, 100%);
  display: grid;
  gap: 8px;
  margin: 0 auto;
}

.result-item {
  padding: 14px 16px;
  background: var(--white);
  box-shadow: var(--shadow-comment);
}

.result-item.correct {
  border-color: color-mix(in srgb, var(--correct) 45%, var(--line));
  background: var(--correct-soft);
}

.result-item.wrong {
  border-color: var(--wrong);
  background: var(--wrong-soft);
}

.result-heading {
  margin-bottom: 8px;
  font-weight: 900;
}

.result-item.correct .result-heading {
  color: var(--correct);
}

.result-item.wrong .result-heading {
  color: var(--wrong);
}

.result-comment {
  margin-bottom: 8px;
  white-space: pre-wrap;
}

.result-meta {
  color: var(--gray);
  font-size: var(--font-small);
  font-weight: 700;
}

@keyframes popText {
  0% { transform: scale(0.72) rotate(-2deg); opacity: 0; }
  70% { transform: scale(1.08) rotate(1deg); opacity: 1; }
  100% { transform: scale(1) rotate(0); opacity: 1; }
}

@keyframes shakeText {
  0%, 100% { transform: translateX(0); }
  15% { transform: translateX(-7px); }
  30% { transform: translateX(7px); }
  45% { transform: translateX(-5px); }
  60% { transform: translateX(5px); }
  75% { transform: translateX(-2px); }
}

@keyframes correctCard {
  0% { border-color: var(--line); background: var(--white); }
  45% { border-color: var(--correct); background: var(--correct-soft); }
  100% { border-color: var(--line); background: var(--white); }
}

@keyframes wrongCard {
  0% { border-color: var(--line); transform: translateX(0); background: var(--white); }
  20% { border-color: var(--wrong); transform: translateX(-7px); background: var(--wrong-soft); }
  40% { transform: translateX(7px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
  100% { border-color: var(--line); transform: translateX(0); background: var(--white); }
}

@keyframes pinponBurst {
  0% { transform: scale(0.2) rotate(-4deg); opacity: 0; }
  28% { transform: scale(1.06) rotate(1deg); opacity: 1; }
  72% { transform: scale(1) rotate(0); opacity: 1; }
  100% { transform: scale(1.12) rotate(0); opacity: 0; }
}

@keyframes batsuBurst {
  0% { transform: scale(0.2) rotate(6deg); opacity: 0; }
  25% { transform: scale(1.06) rotate(-1deg); opacity: 1; }
  35% { transform: scale(1) translateX(-8px); }
  45% { transform: scale(1) translateX(8px); }
  72% { transform: scale(1) translateX(0); opacity: 1; }
  100% { transform: scale(1.12); opacity: 0; }
}

@keyframes ringOut {
  0% { transform: scale(0.72); opacity: 0; }
  30% { opacity: 1; }
  100% { transform: scale(1.23); opacity: 0; }
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.001ms !important;
  }
}

@media (max-width: 700px) {
  body {
    padding: 14px 8px 50px;
  }

  .experiment-container {
    padding: 18px;
  }

  h1 {
    font-size: clamp(2.2rem, 12vw, 3.2rem);
  }

  .sub-comment,
  .article-box,
  .comment-card,
  .feedback-box,
  .result-list,
  .quiz-options,
  .mode-select {
    width: 100%;
  }

  .quiz-options,
  .mode-select {
    grid-template-columns: 1fr;
  }

  .effect-burst {
    width: min(82vw, 360px);
  }
}