/* ===== General Layout ===== */
body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  background-color: #f7f9fc;
  margin: 0;
  padding: 0;
  color: #333;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

.container {
  display: flex;
  flex-direction: column;
  flex: 1;
}

header {
  text-align: center;
  margin: 40px 0 25px 0;
  padding: 0 20px;
  position: relative;
}

header {
  text-align: center;
  margin: 0 0 15px 0;
  padding: 20px 20px;
  background: linear-gradient(135deg, #f8fafc 0%, #ffffff 100%);
  border-radius: 0 0 12px 12px;
  box-shadow: 0 3px 12px rgba(0, 0, 0, 0.06);
  border-bottom: 1px solid #eef3f7;
}

header h1 {
  font-size: 2rem;
  color: #1a3e5c;
  margin-bottom: 6px;
  font-weight: 700;
}

header h2 {
  font-size: 0.95rem;
  color: #666;
  font-weight: 400;
  margin-top: 0;
  line-height: 1.4;
}

.offline-instruction {
  background: linear-gradient(135deg, #e8f5e8, #f1f8e9);
  border: 2px solid #4caf50;
  border-radius: 10px;
  padding: 16px 20px;
  margin: 20px auto;
  max-width: 700px;
}

.instruction-content {
  display: flex;
  align-items: center;
  gap: 16px;
  text-align: left;
}

.instruction-icon {
  font-size: 2rem;
  flex-shrink: 0;
}

.instruction-text {
  color: #2e7d32;
  line-height: 1.5;
  font-size: 0.95rem;
  text-align: center;
}

.highlight {
  background: #c8e6c9;
  padding: 2px 6px;
  border-radius: 4px;
  font-weight: 600;
  color: #1b5e20;
}

/* ===== Main Content ===== */
.main-content {
  flex: 1;
}

.converter-section h2 {
  text-align: center;
  color: #2c3e50;
  margin-bottom: 30px;
  font-size: 1.4rem;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.converter-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(230px, 1fr));
  gap: 25px;
  justify-items: center;
  padding: 0 20px;
}

/* ===== Card Styling ===== */
.converter-card {
  background-color: #fff;
  border-radius: 12px;
  padding: 30px 20px;
  width: 100%;
  max-width: 260px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  transition: transform 0.25s ease, box-shadow 0.25s ease;
  text-align: center;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  height: 340px; /* Taller cards for better screen fill */
}

.converter-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 6px 18px rgba(0, 0, 0, 0.15);
}

/* ===== Card Elements ===== */
.card-icon {
  font-size: 2.2rem;
  color: #007acc;
  margin-bottom: 10px;
}

.card-title {
  font-size: 1.2rem;
  color: #2c3e50;
  margin-bottom: 12px;
}

.card-description {
  font-size: 0.95rem;
  color: #555;
  line-height: 1.4;
  padding: 0 5px;
  flex-grow: 1;
  margin-bottom: 25px;
}

/* ===== Button ===== */
.btn {
  background-color: #007acc;
  color: #fff;
  text-decoration: none;
  text-align: center;
  padding: 10px 15px;
  border-radius: 6px;
  transition: background-color 0.3s, transform 0.15s;
  font-size: 0.9rem;
  font-weight: 500;
  display: inline-block;
  width: 100%;
  max-width: 160px;
  margin: 0 auto;
}

.btn:hover {
  background-color: #005fa3;
  transform: translateY(-1px);
}

/* ===== Footer ===== */
footer {
  text-align: center;
  margin-top: auto;
  padding: 15px 0;
  color: #777;
  font-size: 0.9rem;
  background-color: #f0f2f5;
  border-top: 1px solid #ddd;
}