:root {
  --pastel-blue: #cfeaf3;
  --deep-blue: #164354;
  --soft-white: #f8fcfd;
  --accent: #f2b6a0;
  --secondary-text: #47798a;
  --tertiary-text: #356878;
  --success-color: #176b45;
  --success-light: #ccefdc;
  --error-color: #a23737;
  --error-light: #f6d1d1;
}

* {
  box-sizing: border-box;
}

body {
  min-height: 100vh;
  margin: 0;
  overflow-x: hidden;
  color: var(--deep-blue);
  background: var(--pastel-blue);
  font-family: Arial, sans-serif;
}

.site-logo {
  position: fixed;
  top: 28px;
  right: 28px;
  z-index: 1;
  width: 58px;
  height: 58px;
  box-sizing: content-box;
  object-fit: cover;
  border: 4px solid rgba(248, 252, 253, 0.9);
  border-radius: 50%;
  box-shadow: 0 8px 24px rgba(22, 67, 84, 0.12);
}

.menu-toggle {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
}

.menu-button {
  position: fixed;
  top: 28px;
  left: 28px;
  z-index: 3;
  display: grid;
  width: 66px;
  height: 66px;
  padding: 18px 16px;
  cursor: pointer;
  background: rgba(248, 252, 253, 0.76);
  border: 1px solid rgba(22, 67, 84, 0.12);
  border-radius: 50%;
  box-shadow: 0 8px 24px rgba(22, 67, 84, 0.12);
  gap: 7px;
  transition: background 180ms ease, transform 180ms ease;
}

.menu-button:hover {
  background: var(--soft-white);
  transform: translateY(-2px);
}

.menu-button span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--deep-blue);
  border-radius: 2px;
  transition: transform 180ms ease, opacity 180ms ease;
}

.menu-hint {
  position: fixed;
  top: 61px;
  left: 104px;
  z-index: 2;
  display: flex;
  align-items: center;
  margin: 0;
  color: var(--deep-blue);
  font-size: 0.95rem;
  font-weight: 700;
  white-space: nowrap;
  transform: translateY(-50%);
}

.menu-hint::before {
  margin-right: 7px;
  font-size: 1.5rem;
  content: '<-';
}

.menu {
  position: fixed;
  top: 104px;
  left: 28px;
  z-index: 2;
  display: grid;
  min-width: 180px;
  padding: 12px;
  background: rgba(248, 252, 253, 0.9);
  border: 1px solid rgba(22, 67, 84, 0.1);
  border-radius: 16px;
  box-shadow: 0 16px 40px rgba(22, 67, 84, 0.14);
  opacity: 0;
  pointer-events: none;
  transform: translateY(-8px);
  transition: opacity 180ms ease, transform 180ms ease;
}

.menu a {
  padding: 11px 13px;
  color: var(--deep-blue);
  font-size: 0.95rem;
  text-decoration: none;
  border-radius: 9px;
}

.menu a:hover {
  background: var(--pastel-blue);
}

.menu-toggle:checked ~ .menu {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.menu-toggle:checked + .menu-button span:first-child {
  transform: translateY(7px) rotate(45deg);
}

.menu-toggle:checked + .menu-button span:nth-child(2) {
  opacity: 0;
}

.menu-toggle:checked + .menu-button span:last-child {
  transform: translateY(-7px) rotate(-45deg);
}

.hero {
  display: grid;
  min-height: 100vh;
  padding: 12vh 8vw;
  align-content: center;
  justify-items: center;
  text-align: center;
}

.eyebrow {
  margin: 0 0 12px;
  color: var(--secondary-text);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

h1 {
  max-width: 900px;
  margin: 0;
  color: var(--deep-blue);
  font-family: Arial, sans-serif;
  font-size: clamp(3.4rem, 9vw, 8rem);
  line-height: 0.95;
  letter-spacing: 0;
}

.intro {
  max-width: 430px;
  margin: 28px 0 0;
  color: var(--tertiary-text);
  font-size: clamp(1rem, 2vw, 1.2rem);
  line-height: 1.6;
}

.profile-link {
  margin: 24px 0 0;
  text-align: center;
}

.profile-link a {
  color: var(--deep-blue);
  font-weight: 700;
}

.contact-page {
  width: min(100% - 48px, 620px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 12vh 0 64px;
}

.games-page {
  width: min(100% - 48px, 700px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 12vh 0 64px;
  text-align: center;
}

.games-page h1 {
  margin-bottom: 36px;
  font-size: clamp(3rem, 8vw, 5.5rem);
}

.games-menu {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 14px;
}

.games-menu a {
  padding: 18px 20px;
  color: var(--deep-blue);
  font-size: 1.1rem;
  font-weight: 700;
  text-decoration: none;
  background: rgba(248, 252, 253, 0.8);
  border: 1px solid rgba(22, 67, 84, 0.16);
  border-radius: 8px;
  box-shadow: 0 6px 16px rgba(22, 67, 84, 0.08);
  transition: background 180ms ease, transform 180ms ease;
}

.games-menu a:hover {
  background: var(--soft-white);
  transform: translateY(-2px);
}

.games-menu span {
  margin-left: 5px;
}

.math-game {
  width: min(100% - 48px, 620px);
  min-height: 100vh;
  margin: 0 auto;
  padding: 12vh 0 64px;
  text-align: center;
}

.math-game h1 {
  margin-bottom: 12px;
  font-size: clamp(3rem, 8vw, 5.5rem);
}

.sum-bank {
  display: none;
}

.game-progress {
  margin: 0 0 28px;
  color: var(--secondary-text);
  font-weight: 700;
}

.math-question {
  padding: 28px 24px 30px;
  background: rgba(248, 252, 253, 0.8);
  border: 1px solid rgba(22, 67, 84, 0.16);
  border-radius: 8px;
  box-shadow: 0 6px 16px rgba(22, 67, 84, 0.08);
}

.math-question h2,
.game-result h2 {
  margin: 0 0 24px;
  font-size: clamp(2rem, 6vw, 3.4rem);
}

.answer-progress {
  position: relative;
  display: flex;
  justify-content: space-between;
  max-width: 500px;
  margin: 24px auto 0;
  padding: 0;
  list-style: none;
}

.answer-progress::before {
  position: absolute;
  top: 50%;
  right: 10px;
  left: 10px;
  z-index: -1;
  height: 3px;
  content: '';
  background: rgba(22, 67, 84, 0.2);
}

.answer-progress li {
  display: grid;
  width: 28px;
  height: 28px;
  place-items: center;
  overflow: hidden;
  color: var(--deep-blue);
  font-size: 1.05rem;
  line-height: 1;
  background: var(--pastel-blue);
  border: 2px solid rgba(22, 67, 84, 0.35);
  border-radius: 50%;
}

.answer-progress li.correct {
  color: var(--success-color);
  background: var(--success-light);
  border-color: var(--success-color);
}

.answer-progress li.incorrect {
  color: var(--error-color);
  background: var(--error-light);
  border-color: var(--error-color);
}

.answer-options {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 12px;
}

.answer-options button,
.game-result button {
  min-height: 52px;
  padding: 12px 18px;
  color: var(--soft-white);
  font: inherit;
  font-size: 1.1rem;
  font-weight: 700;
  cursor: pointer;
  background: var(--deep-blue);
  border: 0;
  border-radius: 8px;
  transition: background 180ms ease, transform 180ms ease;
}

.answer-options button:hover,
.game-result button:hover {
  background: #245e70;
  transform: translateY(-2px);
}

.answer-options button:disabled {
  cursor: default;
  opacity: 0.65;
}

.game-feedback {
  min-height: 24px;
  margin: 18px 0 0;
  font-weight: 700;
}

.game-result {
  padding: 28px 24px;
  background: rgba(248, 252, 253, 0.8);
  border: 1px solid rgba(22, 67, 84, 0.16);
  border-radius: 8px;
  box-shadow: 0 6px 16px rgba(22, 67, 84, 0.08);
}

.trophy {
  margin: -8px 0 12px;
  font-size: 5rem;
  line-height: 1;
}

.game-result p {
  margin: 0 0 24px;
  font-size: 1.1rem;
}

.contact-page h1 {
  margin-bottom: 32px;
  font-size: clamp(3rem, 8vw, 5.5rem);
  text-align: center;
}

.contact-form {
  display: grid;
  gap: 10px;
}

.contact-form label {
  margin-top: 12px;
  font-weight: 700;
}

.contact-form input,
.contact-form textarea {
  width: 100%;
  padding: 13px;
  color: var(--deep-blue);
  font: inherit;
  background: rgba(248, 252, 253, 0.8);
  border: 1px solid rgba(22, 67, 84, 0.25);
  border-radius: 8px;
}

.contact-form textarea {
  resize: vertical;
}

.contact-form button {
  width: fit-content;
  margin-top: 18px;
  padding: 12px 22px;
  color: var(--soft-white);
  font: inherit;
  font-weight: 700;
  cursor: pointer;
  background: var(--deep-blue);
  border: 0;
  border-radius: 8px;
}

.contact-form button:hover {
  background: #245e70;
}

@media (max-width: 600px) {
  .menu-button {
    top: 18px;
    left: 18px;
    width: 56px;
    height: 56px;
    padding: 15px 13px;
    gap: 6px;
  }

  .site-logo {
    top: 18px;
    right: 18px;
    width: 48px;
    height: 48px;
    box-sizing: content-box;
  }

  .menu-hint {
    top: 46px;
    left: 94px;
  }

  .menu {
    top: 86px;
    left: 18px;
  }

  .hero {
    padding: 10vh 24px;
  }

  .contact-page {
    padding-top: 96px;
  }

  .games-page {
    padding-top: 96px;
  }

  .math-game {
    padding-top: 96px;
  }
}