* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Nunito", "Lato", sans-serif;
  background: linear-gradient(to bottom, #eaf4ff, #f0fdfa);
  color: #1f2937;
}

/* ANIMATIONS */
.fade-in {
  animation: fadeIn 1.2s ease-in;
}

.slide-up {
  animation: slideUp 1.2s ease-out;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideUp {
  from { opacity: 0; transform: translateY(40px); }
  to { opacity: 1; transform: translateY(0); }
}

/* HOVER EFFECTS */
.hover-grow {
  transition: transform 0.3s ease;
}

.hover-grow:hover {
  transform: scale(1.05);
}

.hover-card {
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.hover-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 15px 35px rgba(0,0,0,0.2);
}

/* HEADER */
.header {
  background: linear-gradient(135deg, #0ea5e9, #2dd4bf);
  color: white;
  text-align: center;
  padding: 50px 20px;
}

.header p {
  max-width: 750px;
  margin: 20px auto;
  background-color: #ccfbf1;
  color: #134e4a;
  padding: 18px;
  border-radius: 25px;
}

.hero-img {
  width: 100%;
  max-width: 450px;
  margin-top: 25px;
}

/* IMAGE GRID */
.image-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 20px;
  padding: 40px 20px;
}

.image-grid img {
  width: 100%;
  border-radius: 20px;
}

/* SECTIONS */
.section {
  max-width: 1000px;
  margin: auto;
  padding: 40px 20px;
}

.section h2 {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: white;
  display: inline-block;
  padding: 10px 22px;
  border-radius: 20px;
  margin-bottom: 20px;
}

/* CARDS */
.card {
  background: white;
  border-radius: 25px;
  padding: 20px;
  margin-bottom: 20px;
  border-left: 8px solid #2dd4bf;
}

summary {
  cursor: pointer;
  font-weight: bold;
}

/* SELECTED PROBLEM */
.selected-problem {
  background: linear-gradient(135deg, #fee2e2, #fecaca);
  border-left: 10px solid #dc2626;
  margin: 40px 20px;
  padding: 30px;
  border-radius: 25px;
  text-align: center;
}

.problem-img {
  width: 100%;
  max-width: 300px;
  margin: 20px auto;
}

/* GRADIENT BOXES */
.gradient-box {
  background: linear-gradient(135deg, #e0f2fe, #bae6fd);
  border-radius: 25px;
}

.gradient-box-alt {
  background: linear-gradient(135deg, #ecfeff, #cffafe);
  border-radius: 25px;
}

/* LEVEL COMPLETE */
.level {
  background: linear-gradient(135deg, #22c55e, #4ade80);
  color: #064e3b;
  text-align: center;
  padding: 45px 20px;
  margin: 50px 20px;
  border-radius: 35px;
  box-shadow: 0 12px 30px rgba(0,0,0,0.25);
}

.progress-container {
  width: 80%;
  background-color: #bbf7d0;
  border-radius: 20px;
  margin: 20px auto;
  height: 20px;
}

.progress-bar {
  width: 100%;
  height: 100%;
  background-color: #15803d;
  border-radius: 20px;
}

/* FOOTER */
.footer {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: white;
  text-align: center;
  padding: 20px;
}

/* MOBILE */
@media (max-width: 600px) {
  .header p {
    font-size: 14px;
  }
}

/* PROPOSED SOLUTION */
.solution {
  background: linear-gradient(135deg, #e0f2fe, #f0fdfa);
  border-radius: 30px;
}

.solution p {
  max-width: 800px;
  margin-bottom: 30px;
}

.solution-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 20px;
}