:root {
  --bg1:#6366f1;
  --bg2:#22d3ee;
  --glass:rgba(255,255,255,.25);
  --border:rgba(255,255,255,.35);
  --text:#111;
}

body.dark {
  --bg1:#020617;
  --bg2:#1e293b;
  --glass:rgba(15,23,42,.8);
  --border:rgba(255,255,255,.12);
  --text:#e5e7eb;
}

* {
  box-sizing:border-box;
  font-family: Inter, system-ui, sans-serif;
}

body {
  margin:0;
  min-height:100vh;
  background:linear-gradient(135deg,var(--bg1),var(--bg2));
  color:var(--text);
  transition:.5s;
}

/* Header */
.topbar {
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:20px;
}

.mode {
  width:40px;
  height:40px;
  border-radius:50%;
  border:none;
  cursor:pointer;
  font-size:18px;
}

/* Tabs */
.tabs {
  display:flex;
  justify-content:center;
  gap:10px;
  flex-wrap:wrap;
  padding:10px;
}

.tabs button {
  padding:10px 16px;
  border-radius:999px;
  border:1px solid var(--border);
  background:var(--glass);
  color:var(--text); /* FIX */
  cursor:pointer;
  backdrop-filter:blur(12px);
  transition:.4s;
}

.tabs button.active,
.tabs button:hover {
  background:#fff;
  color:#000;
}

body.dark .tabs button.active,
body.dark .tabs button:hover {
  background:#020617;
  color:#fff;
}

/* App */
.app {
  display:flex;
  justify-content:center;
  padding:40px 20px;
}

.glass {
  width:100%;
  max-width:420px;
  padding:30px;
  border-radius:24px;
  background:var(--glass);
  border:1px solid var(--border);
  backdrop-filter:blur(18px);
  animation:enter .6s ease;
}

@keyframes enter {
  from { opacity:0; transform:translateY(20px); }
  to { opacity:1; }
}

.inputs input {
  width:100%;
  padding:14px;
  margin-bottom:14px;
  border-radius:14px;
  border:none;
}

.calc {
  width:100%;
  padding:14px;
  border:none;
  border-radius:16px;
  background:#000;
  color:#fff;
  cursor:pointer;
}

/* Footer */
footer {
  text-align:center;
  margin:20px 0;
  font-size:13px;
}

.socials {
  display:flex;
  justify-content:center;
  gap:18px;
  margin-top:10px;
}

.socials a,
.mail-btn {
  width:40px;
  height:40px;
  background:var(--glass);
  border-radius:50%;
  border:1px solid var(--border);
  display:flex;
  align-items:center;
  justify-content:center;
  cursor:pointer;
  transition:.3s;
}

.socials svg {
  width:20px;
  height:20px;
  fill:var(--text);
}

.socials a:hover,
.mail-btn:hover {
  transform:translateY(-4px);
}

.email {
  margin-top:8px;
  opacity:0;
  transition:.3s;
}

.email.show {
  opacity:1;
}