:root{
  --bg:#0b1210;
  --bg2:#0a0f0d;
  --card:#101c18;
  --cream:#eef6f1;
  --muted:#8fa79c;
  --accent:#22c55e;
  --accent-soft:#4ade80;
  --gold:#d4af37;
  --line:rgba(238,246,241,0.12);
}
@media (prefers-color-scheme: light){
  :root:not([data-theme="dark"]){
    --bg:#f3f9f5;
    --bg2:#e7f1ea;
    --card:#ffffff;
    --cream:#0b1210;
    --muted:#4c665a;
    --accent:#15803d;
    --accent-soft:#166534;
    --line:rgba(11,18,16,0.12);
  }
}
:root[data-theme="dark"]{
  --bg:#0b1210;
  --bg2:#0a0f0d;
  --card:#101c18;
  --cream:#eef6f1;
  --muted:#8fa79c;
  --accent:#22c55e;
  --accent-soft:#4ade80;
  --line:rgba(238,246,241,0.12);
}

*{box-sizing:border-box;}
html{overflow-x:hidden;}
body{
  margin:0;
  background:
    radial-gradient(1200px 600px at 50% -10%, var(--bg2), transparent 60%),
    var(--bg);
  color:var(--cream);
  font-family:'Inter', -apple-system, Segoe UI, sans-serif;
  min-height:100vh;
  padding-block:40px;
  padding-inline:16px;
  display:flex;
  justify-content:center;
}
.page{
  width:100%;
  max-width:640px;
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:22px;
}
@keyframes rise{
  from{opacity:0;transform:translateY(14px);}
  to{opacity:1;transform:translateY(0);}
}
.rise{animation:rise 0.5s cubic-bezier(.2,.7,.3,1) both;}
@media (prefers-reduced-motion: reduce){
  .rise{animation:none;}
}

.topbar{
  width:100%;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
}
.brand{
  display:flex;align-items:center;gap:8px;
  font-family:'Poppins', sans-serif;
  font-weight:700;
  font-size:16px;
  text-decoration:none;
  color:var(--cream);
}
.mark{
  width:30px;height:30px;border-radius:9px;
  background:linear-gradient(160deg, var(--accent-soft), var(--accent));
  display:flex;align-items:center;justify-content:center;
  color:var(--bg2);font-weight:700;font-size:14px;
}
.navlinks{display:flex;gap:16px;flex-wrap:wrap;}
.navlinks a{color:var(--muted);text-decoration:none;font-size:13px;font-weight:600;}
.navlinks a:hover{color:var(--accent);}
.theme-toggle{
  flex:none;
  width:36px;height:36px;
  border-radius:10px;
  border:1px solid var(--line);
  background:var(--card);
  color:var(--cream);
  font-size:16px;
  display:flex;align-items:center;justify-content:center;
  cursor:pointer;
  transition:border-color .15s ease;
}
.theme-toggle:hover{border-color:var(--accent);}

.hero{
  display:flex;
  flex-direction:column;
  align-items:center;
  gap:10px;
  text-align:center;
  margin-top:8px;
}
.badge{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:6px 14px;
  border-radius:999px;
  background:rgba(34,197,94,0.12);
  border:1px solid rgba(34,197,94,0.35);
  color:var(--accent);
  font-size:11px;
  font-weight:700;
  letter-spacing:0.5px;
}
h1{
  font-family:'Poppins', sans-serif;
  font-weight:700;
  font-size:clamp(28px,7vw,36px);
  margin:0;
  text-align:center;
}
h1 em{
  font-style:normal;
  color:var(--accent);
}
.tagline{
  margin:0;
  color:var(--muted);
  font-size:14.5px;
  line-height:1.55;
  max-width:440px;
}

.category-label{
  width:100%;
  font-size:11px;
  font-weight:700;
  letter-spacing:1px;
  text-transform:uppercase;
  color:var(--muted);
  margin-top:6px;
}
.calc-nav{
  display:flex;
  flex-wrap:wrap;
  gap:8px;
  width:100%;
  justify-content:center;
}
.calc-tab{
  padding:9px 16px;
  border-radius:999px;
  background:var(--card);
  border:1px solid var(--line);
  font-size:12.5px;
  font-weight:600;
  color:var(--muted);
  cursor:pointer;
  transition:border-color .15s ease, color .15s ease, background .15s ease;
}
.calc-tab:hover{color:var(--cream);}
.calc-tab.active{
  background:rgba(34,197,94,0.14);
  border-color:var(--accent);
  color:var(--accent);
}

.card{
  width:100%;
  background:var(--card);
  border:1px solid var(--line);
  border-radius:18px;
  padding:24px;
  display:none;
  flex-direction:column;
  gap:16px;
}
.card.active{display:flex;}
.card-head{
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:10px;
}
.card-head h2{
  font-family:'Poppins', sans-serif;
  font-size:19px;
  font-weight:600;
  margin:0;
}
.muted-tag{
  font-size:11px;
  color:var(--muted);
  text-transform:uppercase;
  letter-spacing:0.6px;
}

.conv-row{
  display:flex;
  gap:12px;
  flex-wrap:wrap;
}
.field{
  flex:1;
  min-width:130px;
  display:flex;
  flex-direction:column;
  gap:6px;
}
.field label{
  font-size:11.5px;
  color:var(--muted);
  text-transform:uppercase;
  letter-spacing:0.5px;
  font-weight:600;
}
input, select{
  width:100%;
  padding:12px 14px;
  border-radius:12px;
  border:1px solid var(--line);
  background:var(--bg);
  color:var(--cream);
  font-size:15px;
  font-family:inherit;
  outline:none;
  transition:border-color .15s ease;
}
input:focus, select:focus{
  border-color:var(--accent);
}
select{
  appearance:none;
  -webkit-appearance:none;
  background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%238fa79c' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E");
  background-repeat:no-repeat;
  background-position:right 12px center;
  padding-right:34px;
  cursor:pointer;
}

.result-box{
  width:100%;
  padding:18px;
  border-radius:14px;
  background:linear-gradient(135deg, rgba(34,197,94,0.14), transparent 60%);
  border:1px solid rgba(34,197,94,0.3);
  text-align:center;
}
.result-box span{
  font-family:'Poppins', sans-serif;
  font-weight:700;
  font-size:clamp(20px,5.5vw,26px);
  color:var(--accent);
  word-break:break-word;
}
.result-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(140px,1fr));
  gap:10px;
  width:100%;
}
.result-item{
  padding:14px;
  border-radius:12px;
  background:var(--bg);
  border:1px solid var(--line);
  text-align:center;
}
.result-item .label{
  font-size:11px;
  color:var(--muted);
  text-transform:uppercase;
  letter-spacing:0.5px;
  margin-bottom:6px;
}
.result-item .value{
  font-family:'Poppins', sans-serif;
  font-weight:700;
  font-size:16px;
  color:var(--cream);
}
.hint{
  margin:0;
  text-align:center;
  font-size:12px;
  color:var(--muted);
}

.about-card{
  width:100%;
  padding:20px;
  border-radius:16px;
  background:var(--card);
  border:1px solid var(--line);
  color:var(--muted);
  font-size:13.5px;
  line-height:1.7;
}
.about-card h2{
  font-family:'Poppins', sans-serif;
  font-size:16px;
  color:var(--cream);
  margin:0 0 8px;
}

footer{
  text-align:center;
  color:var(--muted);
  font-size:12px;
  margin-top:4px;
}
footer a{color:var(--muted);text-decoration:underline;}

@media (max-width:420px){
  .field{
    min-width:calc(50% - 6px);
  }
}


.lang-switch{position:relative;flex:none;}
.lang-btn{display:flex;align-items:center;gap:6px;padding:7px 12px;border-radius:10px;border:1px solid var(--line);background:var(--card);color:var(--cream);font-size:12.5px;font-weight:600;cursor:pointer;transition:border-color .15s ease;white-space:nowrap;}
.lang-btn:hover{border-color:var(--accent);}
.lang-menu{display:none;position:absolute;top:calc(100% + 8px);right:0;min-width:160px;background:var(--card);border:1px solid var(--line);border-radius:12px;padding:6px;box-shadow:0 10px 30px rgba(0,0,0,0.25);z-index:200;}
.lang-menu.open{display:block;}
.lang-option{display:block;width:100%;text-align:left;padding:9px 12px;border-radius:8px;border:none;background:transparent;color:var(--cream);font-size:13px;cursor:pointer;}
.lang-option:hover{background:var(--bg);}
.lang-option.active{color:var(--accent);font-weight:700;}

@media (max-width:480px){
  .lang-menu{ left:0; right:auto; }
}

@media (max-width:480px){
  .topbar{ flex-wrap:wrap; }
  .navlinks{ order:3; width:100%; justify-content:center; }
}