:root {
  --bg: linear-gradient(180deg, #fffde8, #e6f8e8);
  --text: #14391f;
  --accent: #3d8c3f;
  --box: rgba(255,255,255,0.9);
  --panel: rgba(255,255,255,0.95);
}

body {
  margin: 0;
  font-family: "Poppins", sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background .8s, color .6s;
}

.mode-input { position: absolute; left: -9999px; }

header {
  background: var(--panel);
  text-align: center;
  padding: 16px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.15);
  position: sticky;
  top: 0;
  z-index: 999;
}
header h1 { color: var(--accent); margin: 0; }
.nav-links {
  margin-top: 8px;
  display: flex; justify-content: center; flex-wrap: wrap; gap: 10px;
}
.nav-links a {
  color: var(--text);
  text-decoration: none;
  font-weight: 600;
  transition: .2s;
}
.nav-links a:hover, .nav-links a.active { color: var(--accent); }
.mode-switch {
  position: fixed;
  top: 80px; right: 20px;
}
.mode-switch label {
  font-size: 1.3rem;
  cursor: pointer;
  margin-left: 8px;
}

main { padding: 25px; text-align: center; }

.plan-form {
  background: var(--panel);
  max-width: 600px;
  margin: 25px auto;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}
.options {
  display: flex; flex-wrap: wrap;
  gap: 10px; justify-content: center;
  margin: 10px 0 20px;
}
.option-label {
  background: var(--box);
  border-radius: 8px;
  padding: 10px 12px;
  cursor: pointer;
  font-weight: 600;
  transition: .25s;
}
.option-label:hover { transform: translateY(-3px); box-shadow: 0 3px 10px rgba(0,0,0,0.15); }

input:checked + main .option-label {
  background: var(--accent);
  color: white;
}

.plan-output {
  max-width: 750px;
  margin: 25px auto;
  text-align: left;
}
.plan {
  display: none;
  background: var(--box);
  padding: 15px;
  border-radius: 8px;
  margin-bottom: 15px;
  animation: fadeIn 0.6s ease-in-out;
}
.duration, .group {
  display: none;
  background: var(--panel);
  margin: 8px 0;
  padding: 10px;
  border-radius: 8px;
}
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }

#pur-photo:checked ~ main #plan-photo,
#pur-bird:checked ~ main #plan-bird,
#pur-camp:checked ~ main #plan-camp,
#pur-trek:checked ~ main #plan-trek { display: block; }

#dur-1:checked ~ main #dur-short,
#dur-2:checked ~ main #dur-medium,
#dur-3:checked ~ main #dur-long { display: block; }

#grp-solo:checked ~ main #grp-solo-txt,
#grp-friends:checked ~ main #grp-friends-txt,
#grp-family:checked ~ main #grp-family-txt { display: block; }

.travel-tips {
  max-width: 700px;
  margin: 40px auto;
  text-align: left;
  background: var(--panel);
  padding: 20px;
  border-radius: 10px;
}
.travel-tips h3 { color: var(--accent); text-align: center; }
.travel-tips li { margin: 5px 0; }

#night:checked ~ header,
#night:checked ~ main,
#night:checked ~ footer {
  --bg: linear-gradient(180deg,#0d1c18,#152826,#091311);
  --text: #e8fefb;
  --accent: #78c2b1;
  --box: rgba(25,35,35,0.9);
  --panel: rgba(30,40,40,0.9);
  background: var(--bg);
  color: var(--text);
}