:root {
  --blue-50: #eefaff;
  --blue-100: #d9f2fb;
  --blue-200: #b7e5f4;
  --blue-500: #2f93b5;
  --green-50: #f0fbef;
  --green-100: #d8f2d2;
  --green-500: #4c9f62;
  --yellow-50: #fff9dd;
  --yellow-200: #ffe998;
  --yellow-500: #f5b83c;
  --coral: #ef735b;
  --cold: #62b6e6;
  --copper: #c77a2d;
  --ink: #253845;
  --muted: #5f7480;
  --line: #c9dfe6;
  --paper: #ffffff;
  --shadow: 0 16px 42px rgba(50, 88, 104, 0.13);
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  font-family: "PingFang TC", "Microsoft JhengHei", "Noto Sans TC", system-ui, sans-serif;
  font-size: 18px;
  line-height: 1.7;
  letter-spacing: 0;
  background:
    linear-gradient(180deg, rgba(238, 250, 255, 0.85), rgba(240, 251, 239, 0.9) 48%, rgba(255, 249, 221, 0.62)),
    repeating-linear-gradient(90deg, rgba(47, 147, 181, 0.035) 0 1px, transparent 1px 72px);
  min-width: 320px;
}

button,
select,
textarea {
  font: inherit;
}

button {
  border: 0;
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

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

ul {
  margin: 0;
  padding-left: 1.25rem;
}

li + li {
  margin-top: 0.45rem;
}

main {
  overflow: hidden;
}

section {
  scroll-margin-top: 96px;
}

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 14px clamp(18px, 4vw, 54px);
  border-bottom: 1px solid rgba(102, 154, 171, 0.22);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  min-width: max-content;
  color: #226f88;
  font-size: 1.08rem;
  font-weight: 900;
}

.brand-mark {
  display: grid;
  width: 38px;
  height: 38px;
  place-items: center;
  border: 2px solid #9bd5e6;
  border-radius: 50%;
  color: #ffffff;
  background: linear-gradient(135deg, var(--blue-500), var(--green-500));
  box-shadow: 0 6px 14px rgba(47, 147, 181, 0.24);
}

.nav-links {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 8px;
  flex-wrap: wrap;
}

.nav-links a {
  padding: 8px 12px;
  border-radius: 999px;
  color: #395866;
  font-size: 0.96rem;
  font-weight: 800;
  transition: background 180ms ease, color 180ms ease, transform 180ms ease;
}

.nav-links a:hover,
.nav-links a:focus-visible {
  color: #125c74;
  background: var(--blue-100);
  transform: translateY(-1px);
}

.section-band,
.section-block {
  position: relative;
  padding-inline: clamp(18px, 5vw, 72px);
}

.section-block {
  max-width: 1240px;
  margin-inline: auto;
  padding-top: clamp(68px, 8vw, 104px);
}

.hero {
  min-height: 86vh;
  padding-top: clamp(48px, 6vw, 86px);
  padding-bottom: clamp(38px, 5vw, 72px);
  display: grid;
  align-items: center;
  background:
    linear-gradient(135deg, rgba(217, 242, 251, 0.92), rgba(240, 251, 239, 0.92) 54%, rgba(255, 249, 221, 0.9));
  isolation: isolate;
}

.hero::after {
  content: "";
  position: absolute;
  inset-inline: 0;
  bottom: 0;
  height: 58px;
  background:
    radial-gradient(ellipse at 18% 100%, rgba(76, 159, 98, 0.24), transparent 58%),
    linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.58));
  z-index: -1;
}

.hero-content {
  position: relative;
  z-index: 1;
  width: min(1180px, 100%);
  margin-inline: auto;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(330px, 0.8fr);
  gap: clamp(28px, 5vw, 62px);
  align-items: center;
}

.lesson-label {
  display: inline-flex;
  margin-bottom: 18px;
  padding: 7px 12px;
  border: 1px solid rgba(47, 147, 181, 0.26);
  border-radius: 999px;
  color: #2d6e7f;
  background: rgba(255, 255, 255, 0.72);
  font-size: 1rem;
  font-weight: 800;
}

.hero h1 {
  margin-bottom: 18px;
  color: #213f4a;
  font-size: clamp(3.2rem, 8vw, 7.2rem);
  line-height: 1.02;
  font-weight: 950;
  letter-spacing: 0;
}

.hero-subtitle {
  max-width: 760px;
  margin-bottom: 30px;
  color: #385b69;
  font-size: clamp(1.35rem, 2.6vw, 2.1rem);
  line-height: 1.5;
  font-weight: 800;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.big-action,
.control-btn,
.reset-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  gap: 9px;
  border-radius: 999px;
  font-weight: 900;
  color: #203844;
  box-shadow: 0 10px 20px rgba(38, 90, 106, 0.14);
  transform: translateY(0);
  transition: transform 170ms ease, box-shadow 170ms ease, filter 170ms ease;
}

.big-action {
  min-width: 168px;
  padding: 13px 22px;
  font-size: 1.12rem;
}

.big-action:hover,
.big-action:focus-visible,
.control-btn:hover,
.control-btn:focus-visible,
.reset-btn:hover,
.reset-btn:focus-visible {
  transform: translateY(-3px);
  box-shadow: 0 16px 24px rgba(38, 90, 106, 0.18);
  filter: saturate(1.07);
}

.big-action:active,
.control-btn:active,
.reset-btn:active {
  transform: translateY(1px) scale(0.99);
}

.gas-action {
  background: linear-gradient(135deg, #ffcf8f, #ffdca6);
}

.liquid-action {
  background: linear-gradient(135deg, #a7e4f5, #d1f2fb);
}

.solid-action {
  background: linear-gradient(135deg, #ffd889, #f7b65a);
}

.action-icon {
  font-size: 1.34rem;
}

.hero-lab {
  position: relative;
  padding: 22px;
  border: 2px solid rgba(47, 147, 181, 0.2);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.82), rgba(255, 255, 255, 0.62)),
    radial-gradient(circle at 90% 12%, rgba(245, 184, 60, 0.18), transparent 36%);
  box-shadow: var(--shadow);
}

.hero-lab-title {
  margin-bottom: 18px;
  color: #266a7f;
  font-size: 1.25rem;
  font-weight: 950;
}

.mini-board {
  display: grid;
  gap: 14px;
}

.mini-card {
  display: grid;
  grid-template-columns: 58px 1fr;
  column-gap: 14px;
  align-items: center;
  min-height: 86px;
  padding: 12px;
  border: 1px solid rgba(102, 154, 171, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.76);
}

.mini-card strong {
  display: block;
  color: #213f4a;
  font-size: 1.15rem;
  font-weight: 950;
}

.mini-card small {
  display: block;
  color: var(--muted);
  font-size: 0.96rem;
  font-weight: 800;
}

.mini-icon {
  position: relative;
  display: block;
  width: 54px;
  height: 54px;
}

.balloon-mini::before {
  content: "";
  position: absolute;
  inset: 3px 8px 11px;
  border-radius: 50% 50% 48% 48%;
  background: #f28d7c;
  box-shadow: inset -7px -8px rgba(197, 71, 76, 0.22);
}

.balloon-mini::after {
  content: "";
  position: absolute;
  left: 25px;
  bottom: 2px;
  width: 8px;
  height: 15px;
  border-radius: 0 0 6px 6px;
  background: #d45756;
}

.tube-mini::before {
  content: "";
  position: absolute;
  left: 23px;
  top: 4px;
  width: 10px;
  height: 44px;
  border: 3px solid #8cc7dc;
  border-radius: 999px;
  background: linear-gradient(180deg, transparent 22%, #e9575a 22%);
}

.copper-mini::before {
  content: "";
  position: absolute;
  inset: 8px;
  border-radius: 50%;
  background: radial-gradient(circle at 32% 28%, #ffe59c, #c77a2d 62%, #9d5921);
}

.hero-bg > span {
  position: absolute;
  z-index: 0;
  pointer-events: none;
}

.sun {
  top: 96px;
  right: 9%;
  width: 92px;
  height: 92px;
  border-radius: 50%;
  background: #ffe080;
  box-shadow: 0 0 0 18px rgba(255, 224, 128, 0.25);
}

.cloud {
  width: 136px;
  height: 44px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.74);
}

.cloud::before,
.cloud::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  background: inherit;
}

.cloud::before {
  width: 54px;
  height: 54px;
  left: 18px;
  top: -24px;
}

.cloud::after {
  width: 68px;
  height: 68px;
  right: 18px;
  top: -34px;
}

.cloud-one {
  left: 7%;
  top: 122px;
  animation: drift 7s ease-in-out infinite;
}

.cloud-two {
  right: 18%;
  bottom: 88px;
  transform: scale(0.72);
  opacity: 0.76;
  animation: drift 8.5s ease-in-out infinite reverse;
}

.spark {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--green-500);
  opacity: 0.18;
}

.spark-one {
  left: 46%;
  top: 18%;
}

.spark-two {
  left: 9%;
  bottom: 22%;
  background: var(--yellow-500);
}

@keyframes drift {
  0%,
  100% {
    transform: translateX(0);
  }
  50% {
    transform: translateX(18px);
  }
}

.section-heading {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 18px;
  align-items: start;
  margin-bottom: 28px;
}

.section-number {
  display: grid;
  width: 58px;
  height: 58px;
  place-items: center;
  border: 2px solid rgba(47, 147, 181, 0.24);
  border-radius: 50%;
  color: #ffffff;
  background: var(--blue-500);
  font-weight: 950;
}

.section-heading h2 {
  margin-bottom: 4px;
  color: #213f4a;
  font-size: clamp(2rem, 4vw, 3.2rem);
  line-height: 1.15;
  font-weight: 950;
}

.section-heading p {
  margin-bottom: 0;
  color: var(--muted);
  font-size: clamp(1.05rem, 2vw, 1.24rem);
  font-weight: 750;
}

.key-grid,
.life-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
}

.info-card {
  position: relative;
  padding: 22px;
  border: 1px solid rgba(83, 134, 151, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.84);
  box-shadow: 0 10px 26px rgba(50, 88, 104, 0.08);
  transition: transform 180ms ease, box-shadow 180ms ease, border-color 180ms ease;
}

.info-card:hover {
  transform: translateY(-5px);
  border-color: rgba(47, 147, 181, 0.42);
  box-shadow: 0 20px 34px rgba(50, 88, 104, 0.14);
}

.card-icon {
  display: grid;
  width: 56px;
  height: 56px;
  margin-bottom: 16px;
  place-items: center;
  border-radius: 50%;
  background: var(--yellow-50);
  font-size: 1.75rem;
}

.info-card h3 {
  margin-bottom: 12px;
  color: #264856;
  font-size: 1.24rem;
  line-height: 1.35;
  font-weight: 950;
}

.info-card li,
.info-card p {
  color: #405d69;
  font-size: 1rem;
  font-weight: 700;
}

.experiments-section {
  max-width: 1280px;
}

.experiment-stack {
  display: grid;
  gap: 24px;
}

.experiment-card {
  display: grid;
  grid-template-columns: minmax(290px, 0.92fr) minmax(360px, 1fr);
  gap: clamp(20px, 4vw, 40px);
  align-items: stretch;
  padding: clamp(20px, 3.2vw, 34px);
  border: 2px solid rgba(102, 154, 171, 0.24);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: var(--shadow);
}

.experiment-copy {
  display: flex;
  min-height: 100%;
  flex-direction: column;
  justify-content: center;
}

.experiment-tag {
  width: fit-content;
  margin-bottom: 12px;
  padding: 5px 11px;
  border-radius: 999px;
  color: #1d6c86;
  background: var(--blue-100);
  font-size: 0.95rem;
  font-weight: 900;
}

.experiment-copy h3 {
  margin-bottom: 10px;
  color: #203d49;
  font-size: clamp(1.5rem, 2.6vw, 2.05rem);
  line-height: 1.25;
  font-weight: 950;
}

.experiment-copy p:not(.experiment-tag):not(.experiment-explanation) {
  margin-bottom: 22px;
  color: #496671;
  font-size: 1.08rem;
  font-weight: 700;
}

.control-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 16px;
}

.control-btn {
  padding: 11px 18px;
  font-size: 1.02rem;
}

.hot-btn {
  background: linear-gradient(135deg, #ffd47a, #ffad7f);
}

.cold-btn {
  background: linear-gradient(135deg, #b9e7fb, #c9f0ff);
}

.control-btn.is-selected {
  outline: 3px solid rgba(36, 118, 146, 0.22);
  outline-offset: 2px;
}

.experiment-explanation {
  min-height: 72px;
  margin: 0;
  padding: 14px 16px;
  border-left: 6px solid var(--blue-500);
  border-radius: var(--radius);
  color: #284a56;
  background: var(--blue-50);
  font-size: 1.08rem;
  font-weight: 850;
}

.lab-stage {
  position: relative;
  display: grid;
  min-height: 360px;
  place-items: center;
  overflow: hidden;
  border: 1px solid rgba(102, 154, 171, 0.24);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.78), rgba(238, 250, 255, 0.84)),
    repeating-linear-gradient(0deg, rgba(47, 147, 181, 0.055) 0 1px, transparent 1px 42px);
}

.lab-stage::before {
  content: "";
  position: absolute;
  left: 26px;
  right: 26px;
  bottom: 56px;
  height: 3px;
  border-radius: 999px;
  background: rgba(65, 111, 127, 0.12);
}

.temperature-badge {
  position: absolute;
  top: 18px;
  left: 18px;
  z-index: 4;
  padding: 6px 12px;
  border-radius: 999px;
  color: #264856;
  background: #ffffff;
  box-shadow: 0 8px 16px rgba(50, 88, 104, 0.12);
  font-size: 0.95rem;
  font-weight: 950;
}

.water-bath,
.liquid-bath {
  position: absolute;
  left: 50%;
  bottom: 62px;
  width: min(310px, 70%);
  height: 112px;
  transform: translateX(-50%);
  border: 5px solid rgba(113, 177, 194, 0.42);
  border-top: 0;
  border-radius: 0 0 28px 28px;
  background: linear-gradient(180deg, rgba(155, 213, 230, 0.24), rgba(117, 198, 224, 0.34));
}

.bath-line {
  position: absolute;
  top: 22px;
  left: 10px;
  right: 10px;
  height: 4px;
  border-radius: 999px;
  background: rgba(70, 159, 189, 0.48);
  animation: waterWave 2.8s ease-in-out infinite;
}

.bath-label {
  position: absolute;
  left: 50%;
  bottom: 10px;
  transform: translateX(-50%);
  color: rgba(38, 90, 106, 0.72);
  font-weight: 900;
}

@keyframes waterWave {
  0%,
  100% {
    transform: scaleX(0.94);
  }
  50% {
    transform: scaleX(1);
  }
}

.experiment-card.is-hot .water-bath,
.experiment-card.is-hot .liquid-bath {
  background: linear-gradient(180deg, rgba(255, 220, 142, 0.36), rgba(255, 165, 122, 0.34));
  border-color: rgba(239, 115, 91, 0.42);
}

.experiment-card.is-cold .water-bath,
.experiment-card.is-cold .liquid-bath {
  background: linear-gradient(180deg, rgba(185, 231, 251, 0.48), rgba(98, 182, 230, 0.34));
  border-color: rgba(98, 182, 230, 0.48);
}

.flask {
  position: absolute;
  left: 50%;
  bottom: 98px;
  width: 132px;
  height: 192px;
  transform: translateX(-50%);
}

.flask-neck {
  position: absolute;
  left: 50%;
  top: 0;
  width: 42px;
  height: 86px;
  transform: translateX(-50%);
  border: 5px solid rgba(71, 117, 132, 0.38);
  border-bottom: 0;
  border-radius: 13px 13px 0 0;
  background: rgba(255, 255, 255, 0.45);
}

.flask-body {
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 132px;
  height: 132px;
  transform: translateX(-50%);
  border: 5px solid rgba(71, 117, 132, 0.38);
  border-radius: 20px 20px 42px 42px;
  background:
    radial-gradient(circle at 36% 26%, rgba(255, 255, 255, 0.84), transparent 20%),
    rgba(255, 255, 255, 0.42);
  clip-path: polygon(34% 0, 66% 0, 98% 86%, 88% 100%, 12% 100%, 2% 86%);
}

.air-dot {
  position: absolute;
  z-index: 2;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: #ffd16d;
  opacity: 0.78;
  transition: transform 420ms ease, opacity 420ms ease;
}

.dot-one {
  left: 34px;
  top: 104px;
}

.dot-two {
  right: 36px;
  top: 120px;
}

.dot-three {
  left: 58px;
  top: 150px;
}

.balloon {
  position: absolute;
  left: 50%;
  bottom: 282px;
  z-index: 3;
  width: 72px;
  height: 86px;
  transform: translateX(-50%) scale(0.86);
  transform-origin: 50% 100%;
  border-radius: 50% 50% 48% 48%;
  background:
    radial-gradient(circle at 35% 22%, rgba(255, 255, 255, 0.72), transparent 18%),
    linear-gradient(135deg, #ff9d8d, #e95660 70%);
  box-shadow: inset -10px -14px rgba(151, 53, 72, 0.2), 0 12px 26px rgba(197, 76, 88, 0.16);
  transition: width 520ms ease, height 520ms ease, transform 520ms ease, filter 520ms ease;
}

.balloon::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -13px;
  width: 14px;
  height: 18px;
  transform: translateX(-50%);
  border-radius: 0 0 8px 8px;
  background: #d54e59;
}

.experiment-card.is-hot .balloon {
  width: 118px;
  height: 136px;
  transform: translateX(-50%) translateY(-18px) scale(1);
  animation: balloonPulse 1.15s ease-in-out infinite;
}

.experiment-card.is-cold .balloon {
  width: 52px;
  height: 62px;
  transform: translateX(-50%) translateY(18px) scale(0.96);
  filter: saturate(0.82);
}

.experiment-card.is-hot .air-dot {
  opacity: 1;
}

.experiment-card.is-hot .dot-one {
  transform: translate(-28px, -34px);
}

.experiment-card.is-hot .dot-two {
  transform: translate(30px, -30px);
}

.experiment-card.is-hot .dot-three {
  transform: translateY(-48px);
}

.experiment-card.is-cold .air-dot {
  opacity: 0.54;
}

.experiment-card.is-cold .dot-one {
  transform: translate(14px, 18px);
}

.experiment-card.is-cold .dot-two {
  transform: translate(-14px, 16px);
}

.experiment-card.is-cold .dot-three {
  transform: translateY(12px);
}

@keyframes balloonPulse {
  0%,
  100% {
    transform: translateX(-50%) translateY(-18px) scale(1);
  }
  50% {
    transform: translateX(-50%) translateY(-20px) scale(1.03);
  }
}

.liquid-stage {
  min-height: 400px;
}

.liquid-bath {
  height: 126px;
}

.liquid-bottle {
  position: absolute;
  left: 50%;
  bottom: 104px;
  width: 130px;
  height: 188px;
  transform: translateX(-50%);
}

.liquid-bottle::before {
  content: "";
  position: absolute;
  inset: 62px 0 0;
  z-index: 2;
  border: 5px solid rgba(71, 117, 132, 0.34);
  border-radius: 22px 22px 34px 34px;
  background: rgba(255, 255, 255, 0.4);
  clip-path: polygon(34% 0, 66% 0, 96% 83%, 86% 100%, 14% 100%, 4% 83%);
}

.bottle-neck {
  position: absolute;
  left: 50%;
  top: 24px;
  z-index: 1;
  width: 38px;
  height: 75px;
  transform: translateX(-50%);
  border: 5px solid rgba(71, 117, 132, 0.34);
  border-bottom: 0;
  border-radius: 12px 12px 0 0;
}

.bottle-liquid {
  position: absolute;
  left: 17px;
  right: 17px;
  bottom: 10px;
  z-index: 1;
  height: 74px;
  clip-path: polygon(28% 0, 72% 0, 100% 86%, 88% 100%, 12% 100%, 0 86%);
  border-radius: 0 0 28px 28px;
  background: linear-gradient(180deg, rgba(242, 88, 89, 0.78), rgba(213, 49, 63, 0.9));
  transition: height 520ms ease;
}

.capillary {
  position: absolute;
  left: 50%;
  bottom: 178px;
  z-index: 4;
  width: 18px;
  height: 190px;
  transform: translateX(-50%);
  border: 4px solid rgba(71, 117, 132, 0.38);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.66);
  overflow: hidden;
}

.liquid-column {
  position: absolute;
  left: 3px;
  right: 3px;
  bottom: 0;
  height: 56%;
  border-radius: 999px 999px 0 0;
  background: linear-gradient(180deg, #ff8b82, #e13948);
  transition: height 520ms ease;
}

.meniscus {
  position: absolute;
  left: 50%;
  bottom: calc(56% - 3px);
  z-index: 2;
  width: 14px;
  height: 5px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: #8e2b3b;
  opacity: 0.56;
  transition: bottom 520ms ease;
}

.level-arrow {
  position: absolute;
  right: 48px;
  top: 112px;
  color: #2f7f9a;
  font-weight: 950;
}

.level-arrow::before {
  content: "";
  position: absolute;
  right: 58px;
  top: 18px;
  width: 74px;
  height: 3px;
  border-radius: 999px;
  background: #69aeca;
}

.level-arrow::after {
  content: "";
  position: absolute;
  right: 126px;
  top: 12px;
  width: 14px;
  height: 14px;
  border-left: 3px solid #69aeca;
  border-bottom: 3px solid #69aeca;
  transform: rotate(45deg);
}

.experiment-card.is-hot .liquid-column {
  height: 84%;
}

.experiment-card.is-hot .meniscus {
  bottom: calc(84% - 3px);
}

.experiment-card.is-hot .bottle-liquid {
  height: 82px;
}

.experiment-card.is-cold .liquid-column {
  height: 34%;
}

.experiment-card.is-cold .meniscus {
  bottom: calc(34% - 3px);
}

.experiment-card.is-cold .bottle-liquid {
  height: 66px;
}

.solid-stage {
  min-height: 360px;
}

.copper-ring {
  position: absolute;
  left: 50%;
  top: 170px;
  width: 128px;
  height: 128px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: radial-gradient(circle at 35% 30%, #ffe29a, var(--copper) 64%, #92541d);
  box-shadow: inset -8px -10px rgba(99, 53, 18, 0.18), 0 16px 26px rgba(134, 83, 39, 0.16);
}

.ring-hole {
  position: absolute;
  inset: 29px;
  border-radius: 50%;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.82), rgba(238, 250, 255, 0.9)),
    var(--blue-50);
  border: 2px solid rgba(120, 72, 29, 0.16);
}

.copper-handle {
  position: absolute;
  left: calc(50% + 56px);
  top: 225px;
  width: 170px;
  height: 18px;
  transform: rotate(-8deg);
  border-radius: 999px;
  background: linear-gradient(90deg, #d89742, #ffdc8a, #a76128);
  box-shadow: 0 8px 16px rgba(134, 83, 39, 0.12);
}

.copper-ball {
  position: absolute;
  left: 50%;
  top: 76px;
  z-index: 3;
  width: 82px;
  height: 82px;
  transform: translateX(-50%);
  border-radius: 50%;
  background: radial-gradient(circle at 32% 24%, #fff2b4, #d98934 58%, #99571d);
  box-shadow: inset -10px -12px rgba(90, 47, 15, 0.16), 0 14px 24px rgba(134, 83, 39, 0.18);
  transition: width 520ms ease, height 520ms ease, top 520ms ease, transform 520ms ease;
}

.pass-message {
  position: absolute;
  left: 50%;
  bottom: 44px;
  padding: 8px 14px;
  transform: translateX(-50%) translateY(12px);
  border-radius: 999px;
  color: #276b3a;
  background: var(--green-100);
  font-weight: 950;
  opacity: 0;
  transition: opacity 320ms ease, transform 320ms ease;
}

.experiment-card.is-hot .copper-ball {
  top: 110px;
  width: 110px;
  height: 110px;
  transform: translateX(-50%) rotate(1deg);
  animation: heatGlow 1.2s ease-in-out infinite;
}

.experiment-card.is-cold .copper-ball {
  top: 236px;
  width: 66px;
  height: 66px;
  transform: translateX(-50%);
}

.experiment-card.is-cold .pass-message {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

@keyframes heatGlow {
  0%,
  100% {
    box-shadow: inset -10px -12px rgba(90, 47, 15, 0.16), 0 14px 24px rgba(134, 83, 39, 0.2);
  }
  50% {
    box-shadow: inset -10px -12px rgba(90, 47, 15, 0.16), 0 0 0 12px rgba(255, 173, 127, 0.2), 0 14px 24px rgba(134, 83, 39, 0.24);
  }
}

.life-grid {
  grid-template-columns: repeat(6, minmax(0, 1fr));
}

.life-card {
  grid-column: span 2;
  min-height: 250px;
}

.wide-card {
  grid-column: span 2;
}

.life-illustration {
  display: grid;
  width: 70px;
  height: 70px;
  margin-bottom: 14px;
  place-items: center;
  border-radius: var(--radius);
  color: #21657b;
  background: var(--yellow-50);
  font-size: 2rem;
  font-weight: 950;
}

.hot-air {
  background: linear-gradient(180deg, #ffdf94, #d9f2fb);
}

.thermometer {
  background: #f4fbff;
}

.lid {
  background: #f0fbef;
}

.tiles {
  color: #4c9f62;
  background:
    linear-gradient(90deg, transparent 47%, rgba(76, 159, 98, 0.34) 47% 53%, transparent 53%),
    linear-gradient(0deg, transparent 47%, rgba(76, 159, 98, 0.34) 47% 53%, transparent 53%),
    #f8fff5;
  font-size: 2.4rem;
}

.circuit {
  background: #fff5d0;
  animation: blinkBulb 1.6s ease-in-out infinite;
}

@keyframes blinkBulb {
  0%,
  100% {
    filter: brightness(1);
  }
  50% {
    filter: brightness(1.18);
  }
}

.quiz-panel {
  padding: clamp(18px, 3vw, 28px);
  border: 2px solid rgba(47, 147, 181, 0.2);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: var(--shadow);
}

.quiz-status {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 18px;
}

.quiz-status span {
  display: inline-flex;
  align-items: center;
  min-height: 46px;
  padding: 8px 14px;
  border-radius: 999px;
  color: #22576b;
  background: var(--blue-100);
  font-weight: 950;
}

.quiz-list {
  display: grid;
  gap: 16px;
}

.monster-dex {
  margin-bottom: 18px;
  padding: 16px;
  border: 2px solid rgba(126, 91, 190, 0.2);
  border-radius: 18px;
  background:
    radial-gradient(circle at 95% 10%, rgba(255, 220, 142, 0.34), transparent 24%),
    linear-gradient(135deg, #fbf6ff, #effaff);
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.68);
}

.monster-dex-header {
  display: grid;
  grid-template-columns: 64px 1fr;
  gap: 14px;
  align-items: center;
  margin-bottom: 12px;
}

.monster-dex h3 {
  margin-bottom: 2px;
  color: #4d3f79;
  font-size: 1.3rem;
  font-weight: 950;
}

.monster-dex p {
  margin: 0;
  color: #5d6178;
  font-weight: 850;
}

.monster-badge,
.tiny-monster {
  position: relative;
  display: grid;
  place-items: center;
  background:
    radial-gradient(circle at 35% 28%, rgba(255, 255, 255, 0.72), transparent 20%),
    linear-gradient(135deg, #8f72db, #55b8cf);
  box-shadow: inset -6px -8px rgba(56, 48, 111, 0.16), 0 12px 20px rgba(79, 88, 145, 0.2);
}

.monster-badge {
  width: 58px;
  height: 58px;
  border-radius: 42% 58% 48% 52%;
  animation: monsterBob 2.4s ease-in-out infinite;
}

.tiny-monster {
  width: 48px;
  height: 48px;
  flex: 0 0 auto;
  border-radius: 44% 56% 52% 48%;
}

.monster-eye {
  position: absolute;
  top: 17px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #ffffff;
  box-shadow: inset 0 -2px rgba(37, 56, 69, 0.18);
}

.tiny-monster .monster-eye {
  top: 14px;
  width: 7px;
  height: 7px;
}

.left-eye {
  left: 16px;
}

.right-eye {
  right: 16px;
}

.tiny-monster .left-eye {
  left: 13px;
}

.tiny-monster .right-eye {
  right: 13px;
}

.monster-mouth {
  position: absolute;
  left: 50%;
  bottom: 14px;
  width: 18px;
  height: 8px;
  transform: translateX(-50%);
  border-radius: 0 0 999px 999px;
  background: rgba(37, 56, 69, 0.7);
}

.tiny-monster .monster-mouth {
  bottom: 11px;
  width: 16px;
  height: 7px;
}

.monster-dex-list {
  display: grid;
  gap: 10px;
}

.monster-empty {
  padding: 12px 14px;
  border: 1px dashed rgba(126, 91, 190, 0.35);
  border-radius: 14px;
  color: #607381;
  background: rgba(255, 255, 255, 0.58);
  font-weight: 850;
}

.monster-entry {
  display: grid;
  grid-template-columns: 48px 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 12px;
  border: 2px solid rgba(143, 114, 219, 0.18);
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.82);
  transition: transform 180ms ease, border-color 180ms ease;
}

.monster-entry:hover {
  transform: translateY(-2px);
  border-color: rgba(143, 114, 219, 0.34);
}

.monster-entry.is-tamed {
  border-color: rgba(76, 159, 98, 0.28);
  background: #f2fbef;
}

.monster-entry.is-tamed .tiny-monster {
  background:
    radial-gradient(circle at 35% 28%, rgba(255, 255, 255, 0.72), transparent 20%),
    linear-gradient(135deg, #8edc8d, #61bdd3);
}

.monster-entry-copy strong {
  display: block;
  color: #3f4568;
  font-size: 1rem;
  font-weight: 950;
}

.monster-entry-copy p {
  margin: 2px 0;
  color: #485f6b;
  font-size: 0.95rem;
}

.monster-entry-copy small {
  color: #7b5b37;
  font-weight: 850;
}

.monster-fix-btn,
.correction-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 9px 14px;
  border-radius: 999px;
  color: #ffffff;
  background: linear-gradient(135deg, #7c69d8, #2f93b5);
  box-shadow: 0 10px 18px rgba(79, 88, 145, 0.16);
  font-weight: 950;
  transition: transform 170ms ease, box-shadow 170ms ease;
}

.monster-fix-btn:hover,
.monster-fix-btn:focus-visible,
.correction-btn:hover,
.correction-btn:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 22px rgba(79, 88, 145, 0.22);
}

.monster-tamed-label {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  padding: 8px 12px;
  border-radius: 999px;
  color: #245d35;
  background: #dff4d7;
  font-weight: 950;
}

.question-card {
  padding: 18px;
  border: 1px solid rgba(102, 154, 171, 0.22);
  border-radius: var(--radius);
  background: #ffffff;
  transition: border-color 180ms ease, box-shadow 180ms ease;
}

.question-card.is-correct {
  border-color: rgba(76, 159, 98, 0.54);
  box-shadow: inset 0 0 0 2px rgba(76, 159, 98, 0.12);
}

.question-card.is-wrong {
  border-color: rgba(239, 115, 91, 0.58);
  box-shadow: inset 0 0 0 2px rgba(239, 115, 91, 0.12);
}

.question-card.is-correcting {
  border-color: rgba(143, 114, 219, 0.66);
  box-shadow: inset 0 0 0 3px rgba(143, 114, 219, 0.12), 0 14px 24px rgba(79, 88, 145, 0.08);
}

.question-card.is-monster-tamed {
  animation: tamePop 520ms ease;
}

.question-title {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: start;
  margin-bottom: 14px;
  color: #2b4d59;
  font-size: 1.12rem;
  font-weight: 950;
}

.question-number {
  display: grid;
  width: 36px;
  height: 36px;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  background: var(--green-500);
  font-size: 0.98rem;
}

.option-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
}

.option-btn {
  min-height: 52px;
  padding: 11px 13px;
  border: 2px solid rgba(102, 154, 171, 0.24);
  border-radius: var(--radius);
  color: #2e4e5b;
  background: var(--blue-50);
  text-align: left;
  font-size: 1.02rem;
  font-weight: 850;
  transition: transform 160ms ease, background 160ms ease, border-color 160ms ease;
}

.option-btn:hover:not(:disabled),
.option-btn:focus-visible:not(:disabled) {
  transform: translateY(-2px);
  border-color: rgba(47, 147, 181, 0.5);
  background: #ffffff;
}

.option-btn:disabled {
  cursor: default;
}

.option-btn.correct-answer {
  border-color: rgba(76, 159, 98, 0.74);
  color: #1f5f36;
  background: #e7f7df;
}

.option-btn.wrong-answer {
  border-color: rgba(239, 115, 91, 0.74);
  color: #854133;
  background: #fff0ea;
}

.feedback {
  display: none;
  margin-top: 14px;
  padding: 12px 14px;
  border-radius: var(--radius);
  font-weight: 850;
}

.feedback.show {
  display: block;
}

.feedback.correct {
  color: #225e35;
  background: #e9f7e4;
}

.feedback.wrong {
  color: #824033;
  background: #fff0ea;
}

.feedback.correction {
  color: #4d3f79;
  background: #f4efff;
}

.monster-alert {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 12px;
  align-items: start;
}

.monster-alert strong {
  display: block;
  margin-bottom: 4px;
  font-size: 1.08rem;
}

.monster-alert p,
.monster-success p {
  margin: 0 0 8px;
}

.monster-success strong {
  display: block;
  margin-bottom: 4px;
  font-size: 1.1rem;
}

.wobble {
  animation: monsterWobble 460ms ease both;
}

@keyframes monsterBob {
  0%,
  100% {
    transform: translateY(0) rotate(-2deg);
  }
  50% {
    transform: translateY(-5px) rotate(2deg);
  }
}

@keyframes monsterWobble {
  0%,
  100% {
    transform: rotate(0);
  }
  25% {
    transform: rotate(-9deg);
  }
  75% {
    transform: rotate(9deg);
  }
}

@keyframes tamePop {
  0% {
    transform: scale(1);
  }
  45% {
    transform: scale(1.015);
  }
  100% {
    transform: scale(1);
  }
}

@media (max-width: 760px) {
  .monster-dex {
    padding: 13px;
  }

  .monster-dex-header {
    grid-template-columns: 52px 1fr;
  }

  .monster-badge {
    width: 50px;
    height: 50px;
  }

  .monster-entry {
    grid-template-columns: 44px 1fr;
  }

  .monster-fix-btn,
  .monster-tamed-label {
    grid-column: 1 / -1;
    width: 100%;
  }

  .monster-alert {
    grid-template-columns: 44px 1fr;
  }

  .tiny-monster {
    width: 42px;
    height: 42px;
  }
}

.final-score {
  display: none;
  margin-top: 20px;
  padding: 18px;
  border-radius: var(--radius);
  color: #214f63;
  background: linear-gradient(135deg, var(--yellow-50), var(--blue-50));
  font-size: clamp(1.3rem, 2.3vw, 1.8rem);
  font-weight: 950;
  text-align: center;
}

.final-score.show {
  display: block;
}

.reset-btn {
  margin-top: 18px;
  padding: 12px 20px;
  background: linear-gradient(135deg, var(--green-100), var(--blue-100));
}

.scientist-card {
  padding: clamp(20px, 3vw, 30px);
  border: 2px solid rgba(76, 159, 98, 0.24);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.92), rgba(240, 251, 239, 0.72)),
    var(--paper);
  box-shadow: var(--shadow);
}

.scientist-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-bottom: 22px;
}

.scientist-badge {
  color: #245d35;
  font-size: clamp(1.45rem, 3vw, 2.2rem);
  font-weight: 950;
}

.scientist-icon {
  display: grid;
  width: 64px;
  height: 64px;
  place-items: center;
  border-radius: 50%;
  background: var(--yellow-50);
  font-size: 2rem;
}

.task-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.task-item {
  padding: 18px;
  border: 1px solid rgba(102, 154, 171, 0.22);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.82);
}

.full-task {
  grid-column: 1 / -1;
}

.task-item h3 {
  margin-bottom: 8px;
  color: #2a6d83;
  font-size: 1.24rem;
  font-weight: 950;
}

.task-item label,
.task-item p {
  display: block;
  margin-bottom: 10px;
  color: #3b5965;
  font-weight: 850;
}

textarea,
select {
  width: 100%;
  border: 2px solid rgba(102, 154, 171, 0.28);
  border-radius: var(--radius);
  color: var(--ink);
  background: #ffffff;
  transition: border-color 160ms ease, box-shadow 160ms ease;
}

textarea {
  min-height: 112px;
  padding: 12px 14px;
  resize: vertical;
}

select {
  margin-top: 8px;
  padding: 10px 12px;
}

textarea:focus,
select:focus {
  outline: none;
  border-color: var(--blue-500);
  box-shadow: 0 0 0 4px rgba(47, 147, 181, 0.12);
}

.sort-list {
  display: grid;
  gap: 12px;
}

.teacher-section {
  padding-bottom: clamp(72px, 8vw, 112px);
}

.teacher-details {
  border: 2px solid rgba(47, 147, 181, 0.2);
  border-radius: var(--radius);
  background: rgba(255, 255, 255, 0.9);
  box-shadow: var(--shadow);
  overflow: hidden;
}

.teacher-details summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  padding: 20px 24px;
  color: #22576b;
  background: var(--blue-100);
  font-size: 1.2rem;
  font-weight: 950;
  cursor: pointer;
  list-style: none;
}

.teacher-details summary::-webkit-details-marker {
  display: none;
}

.summary-icon {
  position: relative;
  width: 24px;
  height: 24px;
  flex: 0 0 auto;
}

.summary-icon::before,
.summary-icon::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 50%;
  width: 18px;
  height: 4px;
  transform: translate(-50%, -50%);
  border-radius: 999px;
  background: #22576b;
  transition: transform 180ms ease;
}

.summary-icon::after {
  transform: translate(-50%, -50%) rotate(90deg);
}

.teacher-details[open] .summary-icon::after {
  transform: translate(-50%, -50%) rotate(0);
}

.teacher-content {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 22px;
  padding: 24px;
}

.teacher-content h3 {
  margin-bottom: 10px;
  color: #274b57;
  font-size: 1.25rem;
  font-weight: 950;
}

.teacher-content li {
  color: #405d69;
  font-weight: 760;
}

.site-footer {
  padding: 30px 18px 38px;
  color: #245d35;
  background: linear-gradient(135deg, var(--green-100), var(--yellow-50));
  text-align: center;
  font-size: 1.2rem;
  font-weight: 950;
}

.site-footer p {
  margin: 0;
}

@media (max-width: 1080px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 10px;
  }

  .nav-links {
    justify-content: flex-start;
  }

  .hero {
    min-height: auto;
  }

  .hero-content,
  .experiment-card {
    grid-template-columns: 1fr;
  }

  .hero-lab {
    max-width: 680px;
  }

  .key-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .life-card,
  .wide-card {
    grid-column: span 3;
  }
}

@media (max-width: 760px) {
  body {
    font-size: 16px;
  }

  section {
    scroll-margin-top: 148px;
  }

  .site-header {
    padding: 12px 16px;
  }

  .brand {
    font-size: 1rem;
  }

  .brand-mark {
    width: 34px;
    height: 34px;
  }

  .nav-links {
    width: 100%;
    overflow-x: auto;
    flex-wrap: nowrap;
    padding-bottom: 2px;
  }

  .nav-links a {
    min-width: max-content;
    padding: 7px 10px;
    font-size: 0.9rem;
  }

  .hero {
    padding-top: 42px;
  }

  .hero h1 {
    font-size: clamp(2.7rem, 15vw, 4.6rem);
  }

  .hero-subtitle {
    font-size: 1.2rem;
  }

  .lesson-label {
    font-size: 0.9rem;
  }

  .big-action {
    width: 100%;
    min-width: 0;
  }

  .section-block {
    padding-top: 58px;
  }

  .section-heading {
    grid-template-columns: 1fr;
    gap: 10px;
  }

  .section-number {
    width: 48px;
    height: 48px;
  }

  .key-grid,
  .life-grid,
  .task-grid,
  .teacher-content,
  .option-grid {
    grid-template-columns: 1fr;
  }

  .life-card,
  .wide-card,
  .full-task {
    grid-column: auto;
  }

  .experiment-card {
    padding: 18px;
  }

  .lab-stage {
    min-height: 330px;
  }

  .liquid-stage {
    min-height: 370px;
  }

  .control-btn {
    flex: 1 1 100%;
  }

  .level-arrow {
    right: 24px;
  }

  .level-arrow::before {
    width: 48px;
    right: 54px;
  }

  .level-arrow::after {
    right: 96px;
  }

  .copper-handle {
    left: calc(50% + 42px);
    width: 122px;
  }

  .teacher-details summary {
    padding: 16px 18px;
    font-size: 1.05rem;
  }
}

@media (max-width: 440px) {
  .mini-card {
    grid-template-columns: 1fr;
  }

  .mini-icon {
    margin-bottom: 8px;
  }

  .flask,
  .liquid-bottle {
    transform: translateX(-50%) scale(0.9);
  }

  .capillary {
    transform: translateX(-50%) scale(0.92);
  }

  .water-bath,
  .liquid-bath {
    width: 82%;
  }

  .copper-ring {
    width: 112px;
    height: 112px;
  }

  .ring-hole {
    inset: 26px;
  }

  .experiment-card.is-hot .copper-ball {
    width: 100px;
    height: 100px;
  }
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    scroll-behavior: auto !important;
    transition-duration: 0.01ms !important;
  }
}

/* Image2 asset refresh: larger, more intuitive visuals for elementary learners. */
.hero-lab {
  padding: 0;
  overflow: hidden;
  border: 0;
  background: transparent;
  box-shadow: none;
}

.hero-art {
  display: block;
  width: 100%;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  border: 10px solid rgba(255, 255, 255, 0.72);
  border-radius: 18px;
  box-shadow: 0 24px 54px rgba(50, 88, 104, 0.18);
  animation: gentleFloat 4.8s ease-in-out infinite;
}

.hero-lab-panel {
  position: absolute;
  left: 22px;
  bottom: 22px;
  display: grid;
  gap: 2px;
  max-width: min(390px, calc(100% - 44px));
  padding: 14px 16px;
  border-radius: 14px;
  color: #1f4d5e;
  background: rgba(255, 255, 255, 0.9);
  box-shadow: 0 12px 24px rgba(38, 90, 106, 0.16);
}

.hero-lab-panel strong {
  font-size: 1.18rem;
  font-weight: 950;
}

.hero-lab-panel span {
  font-weight: 850;
}

.action-step {
  display: grid;
  width: 34px;
  height: 34px;
  place-items: center;
  border-radius: 50%;
  color: #ffffff;
  background: rgba(33, 63, 74, 0.82);
  font-size: 1rem;
}

.learning-map {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.learning-map span {
  position: relative;
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 7px 13px;
  border: 2px solid rgba(47, 147, 181, 0.18);
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.72);
  color: #2c6375;
  font-size: 0.98rem;
  font-weight: 900;
}

.text-icon {
  width: auto;
  min-width: 68px;
  padding-inline: 12px;
  border-radius: 999px;
  color: #21627a;
  background: linear-gradient(135deg, #fff6c8, #d9f2fb);
  font-size: 1.04rem;
  font-weight: 950;
}

.student-prompt {
  margin: 2px 0 18px;
  padding: 10px 12px;
  border-radius: 12px;
  color: #286141;
  background: #edf9e9;
  font-size: 1.02rem;
  font-weight: 900;
}

.experiment-card {
  border-radius: 18px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(247, 253, 255, 0.9)),
    #ffffff;
}

.image-stage {
  min-height: 430px;
  padding: 16px;
  isolation: isolate;
  background:
    radial-gradient(circle at 14% 10%, rgba(255, 234, 158, 0.42), transparent 32%),
    linear-gradient(180deg, rgba(238, 250, 255, 0.98), rgba(240, 251, 239, 0.94));
}

.image-stage::before {
  display: none;
}

.state-image {
  position: absolute;
  inset: 18px;
  z-index: 1;
  width: calc(100% - 36px);
  height: calc(100% - 36px);
  border: 8px solid rgba(255, 255, 255, 0.86);
  border-radius: 18px;
  object-fit: cover;
  opacity: 0;
  transform: scale(0.96);
  box-shadow: 0 18px 36px rgba(50, 88, 104, 0.14);
  transition: opacity 440ms ease, transform 520ms ease, filter 420ms ease;
}

.image-stage .state-hot {
  opacity: 1;
  transform: scale(1);
}

.experiment-card.is-hot .state-hot,
.experiment-card.is-cold .state-cold {
  opacity: 1;
  transform: scale(1.02);
}

.experiment-card.is-hot .state-cold,
.experiment-card.is-cold .state-hot {
  opacity: 0;
  transform: scale(0.96);
}

.experiment-card.is-hot .state-hot {
  filter: saturate(1.08) brightness(1.02);
}

.experiment-card.is-cold .state-cold {
  filter: saturate(1.04) brightness(1.02);
}

.state-callout {
  position: absolute;
  left: 50%;
  bottom: 30px;
  z-index: 4;
  min-width: min(80%, 360px);
  padding: 12px 16px;
  transform: translateX(-50%);
  border-radius: 999px;
  color: #224e60;
  background: rgba(255, 255, 255, 0.94);
  box-shadow: 0 12px 22px rgba(38, 90, 106, 0.18);
  text-align: center;
  font-size: 1.05rem;
  font-weight: 950;
}

.motion-layer {
  position: absolute;
  inset: 0;
  z-index: 3;
  overflow: hidden;
  pointer-events: none;
  opacity: 0;
  transition: opacity 260ms ease;
}

.experiment-card.is-hot .motion-layer,
.experiment-card.is-cold .motion-layer {
  opacity: 1;
}

.motion-layer span {
  position: absolute;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #ffb84f;
  box-shadow: 0 0 0 9px rgba(255, 184, 79, 0.16);
  animation: bubbleFloat 2.4s ease-in-out infinite;
}

.motion-layer span:nth-child(1) {
  left: 18%;
  top: 68%;
}

.motion-layer span:nth-child(2) {
  left: 35%;
  top: 22%;
  animation-delay: 0.35s;
}

.motion-layer span:nth-child(3) {
  right: 22%;
  top: 28%;
  animation-delay: 0.7s;
}

.motion-layer span:nth-child(4) {
  right: 18%;
  bottom: 22%;
  animation-delay: 1.05s;
}

.experiment-card.is-cold .motion-layer span {
  background: #7ec8ef;
  box-shadow: 0 0 0 9px rgba(126, 200, 239, 0.18);
  animation-name: snowDrift;
}

.experiment-card.is-hot .temperature-badge {
  color: #78431b;
  background: #fff0c5;
}

.experiment-card.is-cold .temperature-badge {
  color: #1e607c;
  background: #e1f4ff;
}

.life-card {
  display: flex;
  flex-direction: column;
  min-height: 100%;
  padding: 16px;
  border-radius: 18px;
}

.life-image {
  display: block;
  width: 100%;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  margin-bottom: 16px;
  border-radius: 16px;
  background: var(--blue-50);
  box-shadow: 0 12px 24px rgba(50, 88, 104, 0.1);
  transition: transform 220ms ease, filter 220ms ease;
}

.life-card:hover .life-image {
  transform: translateY(-4px) scale(1.02);
  filter: saturate(1.06);
}

.scientist-icon {
  position: relative;
}

.scientist-icon::before,
.scientist-icon::after {
  content: "";
  position: absolute;
}

.scientist-icon::before {
  width: 30px;
  height: 30px;
  border: 5px solid #3f9cbc;
  border-radius: 50%;
  transform: translate(-4px, -4px);
}

.scientist-icon::after {
  width: 22px;
  height: 6px;
  border-radius: 999px;
  background: #3f9cbc;
  transform: translate(18px, 20px) rotate(45deg);
}

@keyframes gentleFloat {
  0%,
  100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-8px);
  }
}

@keyframes bubbleFloat {
  0% {
    transform: translateY(12px) scale(0.82);
    opacity: 0;
  }
  42% {
    opacity: 0.85;
  }
  100% {
    transform: translateY(-42px) scale(1.08);
    opacity: 0;
  }
}

@keyframes snowDrift {
  0% {
    transform: translate(8px, -14px) scale(0.9);
    opacity: 0;
  }
  40% {
    opacity: 0.88;
  }
  100% {
    transform: translate(-18px, 40px) scale(1.05);
    opacity: 0;
  }
}

@media (max-width: 1080px) {
  .hero-art {
    max-height: 520px;
  }

  .image-stage {
    min-height: 390px;
  }
}

@media (max-width: 760px) {
  .hero-lab-panel {
    position: static;
    max-width: none;
    margin-top: 12px;
    transform: none;
  }

  .hero-art {
    border-width: 6px;
    border-radius: 16px;
  }

  .learning-map span {
    width: 100%;
    justify-content: center;
  }

  .image-stage {
    min-height: 330px;
    padding: 10px;
  }

  .state-image {
    inset: 10px;
    width: calc(100% - 20px);
    height: calc(100% - 20px);
    border-width: 5px;
  }

  .state-callout {
    bottom: 18px;
    min-width: calc(100% - 38px);
    border-radius: 14px;
    font-size: 0.96rem;
  }
}