:root {
  --bg-start: #2a3b5a;
  --bg-end: #18202f;
  --card: rgba(255, 255, 255, 0.12);
  --card-border: rgba(255, 255, 255, 0.18);
  --text: #f3f7ff;
  --muted: #cdd5ea;
}

* {
  box-sizing: border-box;
}

html,
body {
  height: 100%;
  margin: 0;
  padding: 0;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  color: var(--text);
}

body {
  background:
    radial-gradient(
      circle at top left,
      rgba(97, 168, 255, 0.18),
      transparent 23%
    ),
    radial-gradient(
      circle at bottom right,
      rgba(255, 190, 100, 0.18),
      transparent 20%
    ),
    linear-gradient(135deg, var(--bg-start), var(--bg-end));
  min-height: 100vh;
  display: grid;
  place-items: center;
  overflow-x: hidden;
}

.hero {
  width: min(100%, 980px);
  padding: 16px;
}

.hero-card {
  background: var(--card);
  border: 1px solid var(--card-border);
  border-radius: 32px;
  backdrop-filter: blur(18px);
  box-shadow: 0 30px 90px rgba(0, 0, 0, 0.32);
  padding: 40px;
}

.hero-brand {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 32px;
}

.hero-icon {
  display: grid;
  place-items: center;
  width: 84px;
  height: 84px;
  padding: 0;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 24px;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.08);
  flex-shrink: 0;
  font-size: 2.4rem;
}

.hero-logo {
  width: 100%;
  height: 100%;
  object-fit: contain;
  border-radius: 20px;
}

h1 {
  margin: 0;
  font-size: clamp(1.75rem, 5vw, 4.5rem);
  letter-spacing: -1px;
}

.hero-brand p {
  margin: 8px 0 0;
  max-width: 520px;
  color: var(--muted);
  line-height: 1.65;
  font-size: 1.05rem;
}

.mode-section h2 {
  margin-top: 0;
  font-size: clamp(1.25rem, 4vw, 1.85rem);
  color: #e9f2ff;
}

.mode-buttons {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
  margin-top: 22px;
}

.mode-btn {
  flex: 1 1 100%;
  max-width: 240px;
  padding: 16px 20px;
  border: none;
  border-radius: 18px;
  font-size: 1rem;
  font-weight: 700;
  cursor: pointer;
  transition:
    transform 0.25s ease,
    box-shadow 0.25s ease,
    background-color 0.25s ease;
  box-shadow: 0 16px 28px rgba(0, 0, 0, 0.16);
  min-height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
}

.mode-btn:hover {
  transform: translateY(-3px);
}

.mode-btn:active {
  transform: translateY(-1px);
}

.mode-btn.easy {
  background: linear-gradient(135deg, #4ade80, #16a34a);
  color: #fff;
}

.mode-btn.medium {
  background: linear-gradient(135deg, #fb923c, #dc2626);
  color: #fff;
}

.mode-btn.hard {
  background: linear-gradient(135deg, #f87171, #b91c1c);
  color: #fff;
}

.mode-btn.easy:hover {
  box-shadow: 0 20px 35px rgba(56, 189, 126, 0.35);
}

.mode-btn.medium:hover {
  box-shadow: 0 20px 35px rgba(251, 146, 60, 0.35);
}

.mode-btn.hard:hover {
  box-shadow: 0 20px 35px rgba(248, 113, 113, 0.35);
}

a {
  text-decoration: none;
}
button {
  background-color: lawngreen;
  border: 3px solid brown;
  font-size: 25px;
  font-weight: bold;
  color: black;
  width: 200px;
  height: 100px;
  margin: auto;
  margin-left: 30px;
  margin-right: 30px;
  cursor: pointer;
  margin-top: 20px;
}
#easy-btn {
  background-color: lawngreen;
  color: white;
  border: black 2px solid;
  box-shadow:
    0 0 5px lawngreen,
    0 0 10px lawngreen;
  text-shadow: 0 0 10px silver;
}
#easy-btn:hover {
  background-color: green;
  box-shadow:
    0 0 10px green,
    0 0 20px green;
  transition: 2.5s 5px ease-in-out;
}
#medium-btn {
  background-color: orange;
  color: white;
  border: black 2px solid;
  box-shadow:
    0 0 5px orange,
    0 0 10px orange;
  text-shadow: 0 0 10px silver;
}
#medium-btn:hover {
  background-color: #dd571c;
  box-shadow:
    0 0 10px #dd571c,
    0 0 20px #dd571c;
  transition: 2.5s 10px ease-in-out;
}

#hard-btn {
  background-color: red;
  color: white;
  border: black 2px solid;
  box-shadow:
    0 0 5px red,
    0 0 10px red;
  text-shadow: 0 0 10px silver;
}
#hard-btn:hover {
  background-color: darkred;
  box-shadow:
    0 0 10px darkred,
    0 0 20px darkred;
  transition: 2.5s 5px ease-in-out;
}

@media (max-width: 768px) {
  .hero {
    padding: 12px;
  }

  .hero-card {
    padding: 20px;
    border-radius: 20px;
  }

  .hero-brand {
    flex-direction: column;
    text-align: center;
    gap: 12px;
  }

  .hero-icon {
    font-size: 2.5rem;
    padding: 16px;
    border-radius: 16px;
  }

  h1 {
    font-size: clamp(1.5rem, 6vw, 2.5rem);
  }

  .hero-brand p {
    max-width: 100%;
    font-size: 0.9rem;
    line-height: 1.5;
  }

  .mode-section h2 {
    font-size: 1.3rem;
    margin-bottom: 16px;
  }

  .mode-buttons {
    gap: 10px;
  }

  .mode-btn {
    flex: 1 1 calc(50% - 5px);
    max-width: 100%;
    padding: 14px 16px;
    font-size: 0.95rem;
    min-height: 52px;
  }

  .mode-btn:hover {
    transform: none;
  }

  button {
    width: 85% !important;
    height: auto !important;
    min-height: 48px !important;
    padding: 12px 16px !important;
    font-size: 16px !important;
    margin: 10px auto !important;
  }

  #brand,
  #slogan,
  #how,
  #warn {
    font-size: 14px;
    margin: 5px 8px;
  }

  #slogan {
    font-size: 16px;
  }
}

@media (max-width: 480px) {
  .hero-card {
    padding: 16px;
  }

  h1 {
    font-size: 1.5rem;
  }

  .hero-brand {
    margin-bottom: 20px;
  }

  .hero-icon {
    font-size: 2rem;
    padding: 12px;
  }

  .mode-section h2 {
    font-size: 1.1rem;
  }

  .mode-buttons {
    flex-direction: column;
  }

  .mode-btn {
    flex: 1 1 100%;
    max-width: 100%;
    width: 100%;
    padding: 16px 12px;
    font-size: 0.9rem;
    min-height: 50px;
  }

  #brand {
    font-size: 12px;
  }

  #slogan {
    font-size: 14px;
    margin-top: 8px;
  }

  #how {
    font-size: 13px;
    margin-top: 5px;
  }

  #warn {
    font-size: 13px;
    margin-top: 3px;
  }

  #heart {
    font-size: 16px;
  }
}
#brand {
  font-size: clamp(13px, 2.5vw, 17px);
  color: #cdd5ea;
  margin-right: 10px;
  margin-top: 7.5px;
  margin-left: 5.5px;
  text-align: center;
  text-shadow: 0 0 3.6px #cdd5ea;
  font-weight: 475px;
  line-height: 1.4;
}
#slogan {
  font-size: clamp(16px, 3vw, 20.5px);
  color: #cdd5ea;
  margin-right: 10px;
  margin-top: 10px;
  margin-left: 5.5px;
  text-align: center;
  text-shadow: 0 0 3.5px #cdd5ea;
  font-weight: 450px;
  line-height: 1.4;
}
#how {
  font-size: clamp(14px, 2.5vw, 17.5px);
  color: #cdd5ea;
  margin: 0px 10px 5px 5.5px;
  text-align: center;
  text-shadow: 0 0 3.5px #cdd5ea;
  font-weight: 350px;
  line-height: 1.5;
}
#warn {
  font-size: clamp(14px, 2.5vw, 18px);
  color: #cdd5ea;
  margin: 0px 10px 3px 5.5px;
  text-align: center;
  text-shadow: 0 0 3px #cdd5ea;
  font-weight: 400px;
  line-height: 1.4;
}
#heart {
  font-size: clamp(16px, 3vw, 19px);
  color: pink;
  text-shadow: 0 0 6px pink;
  display: inline-block;
  transition: all 0.3s ease;
}
#heart:hover {
  color: red;
  text-shadow: 0 0 7px red;
  transform: scale(1.2);
  font-size: clamp(16px, 3vw, 24.5px);
}