:root {
  --primary-gradient: linear-gradient(135deg, #0d6efd, #00c6ff);
  --secondary-color: #6c757d;
  --background-color: #f8f9fa;
  --card-background: #ffffff;
  --text-color: #212529;
  --border-color: #dee2e6;
  --card-shadow: 0 15px 35px rgba(0, 0, 0, 0.08);
  --space-sm: 8px;
  --space-md: 16px;
  --space-lg: 24px;
  --space-xl: 32px;
}

/* Wrapper & cards */
.kdv-calculator-wrapper {
  font-family: 'Poppins', sans-serif;
  background-color: var(--background-color);
  padding: var(--space-lg);
  max-width: 600px;
  margin: 0 auto;
  position: relative;
}

.kdv-calculator-card,
.kdv-results-card {
  background: var(--card-background);
  border-radius: 16px;
  box-shadow: var(--card-shadow);
  overflow: hidden;
  width: 100%;
  transition: opacity 0.4s ease-in-out, transform 0.4s ease-in-out, visibility 0.4s;
}

/* --- Header */
.card-header {
  padding: var(--space-lg) var(--space-xl);
  background: var(--primary-gradient);
  color: white;
  text-align: center;
}
.card-header h2,
.card-header h3 {
  margin: 0;
  font-weight: 700;
  font-size: clamp(1.35rem, 3.6vw, 1.6rem);
}
.card-header p {
  margin: var(--space-sm) 0 0;
  opacity: 0.9;
  font-size: clamp(0.82rem, 2.2vw, 0.95rem);
}

/* Sonuç kartı başlığını özellikle daha küçük yap */
.kdv-results-card .card-header {
  padding: 14px 18px;
}
.kdv-results-card .card-header h3 {
  font-size: clamp(1rem, 2.8vw, 1.15rem);
}

/* Form */
.kdv-calculator-card form { padding: var(--space-xl); }
.form-group { margin-bottom: var(--space-xl); }
.group-title {
  display: block;
  font-weight: 600;
  margin-bottom: var(--space-md);
  color: var(--text-color);
  font-size: clamp(0.95rem, 2.8vw, 1.05rem);
}

/* Radio tiles */
.radio-tile-group {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(130px, 1fr));
  gap: var(--space-md);
}
.radio-tile {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  padding: var(--space-md);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  cursor: pointer;
  transition: all 0.2s ease-in-out;
}
.radio-tile input { display: none; }
.radio-tile span {
  font-weight: 600;
  font-size: clamp(0.82rem, 2.2vw, 0.92rem);
}
.radio-tile small {
  color: var(--secondary-color);
  font-size: clamp(0.72rem, 2vw, 0.82rem);
  margin-top: 4px;
}
.radio-tile:hover { border-color: #0d6efd; }
/* :has fallback */
.radio-tile input:checked + span,
.radio-tile input:checked ~ span,
.radio-tile input:checked ~ small { color: #0056b3; }
.radio-tile:has(input:checked) {
  background-color: #e9f2ff;
  border-color: #0d6efd;
  color: #0056b3;
}

/* KDV oranları kompakt ızgara */
.radio-tile-group.small {
  grid-template-columns: repeat(auto-fit, minmax(58px, 1fr));
}

/* “Diğeri” oranını görünmez yap (HTML’e dokunmadan) */
.radio-tile.diger-oran { display: none !important; }

/* Tutar input */
#tutar-input {
  width: 100%;
  padding: var(--space-md);
  border: 2px solid var(--border-color);
  border-radius: 12px;
  font-size: 1rem;
  box-sizing: border-box;
  transition: border-color 0.2s;
}
#tutar-input:focus { border-color: #0d6efd; outline: none; }

/* Switch (ortakla paylaştır) */
.switch-group {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #f8f9fa;
  padding: var(--space-md);
  border-radius: 12px;
  transition: opacity 0.3s, background-color 0.3s;
}
.switch-group.group-disabled {
  opacity: 0.5;
  background-color: #e9ecef;
  cursor: not-allowed;
}
.switch-group label { margin: 0; flex: 1; cursor: pointer; }
.switch-group span { font-weight: 600; display: block; font-size: clamp(0.88rem, 2.2vw, 0.95rem); }
.switch-group small { font-size: clamp(0.74rem, 2vw, 0.82rem); color: var(--secondary-color); }

.switch-container { position: relative; display: inline-block; width: 60px; height: 34px; }
.switch-container input {
  position: absolute; inset: 0; width: 100%; height: 100%;
  opacity: 0; cursor: pointer; margin: 0; z-index: 2;
}
.slider {
  position: absolute; cursor: pointer; top: 0; left: 0; right: 0; bottom: 0;
  background-color: #ccc; transition: .4s; border-radius: 34px; pointer-events: none;
}
.slider:before {
  position: absolute; content: ""; height: 26px; width: 26px; left: 4px; bottom: 4px;
  background-color: white; transition: .4s; border-radius: 50%;
}
input:checked + .slider { background-image: var(--primary-gradient); }
input:checked + .slider:before { transform: translateX(26px); }

/* Buttons */
.form-buttons { display: flex; gap: var(--space-md); margin-top: var(--space-xl); }
.hesapla-button, .sifirla-button {
  flex: 1; padding: var(--space-md); border: none; border-radius: 12px;
  font-size: 1rem; font-weight: 600; cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s, opacity .2s;
}
.hesapla-button {
  background-image: var(--primary-gradient);
  color: #fff !important;   /* kırmızı görünmeyi bastır */
  font-weight: 700;          /* biraz daha kalın */
}
.sifirla-button { background-color: var(--border-color); color: var(--secondary-color); }
.hesapla-button:hover { transform: translateY(-2px); box-shadow: 0 4px 15px rgba(13,110,253,.3); }
.hesapla-button:disabled { opacity: .6; cursor: not-allowed; }

/* Results */
#kdv-results-content { min-height: 160px; }
.results-footer { padding: 0 var(--space-xl) var(--space-xl); text-align: center; }

.results-group { padding: var(--space-xl); }
.results-group p {
  display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center;
  margin: 0 0 var(--space-md); padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--border-color);
  font-size: clamp(0.88rem, 2.4vw, 0.98rem);
}
.results-group p span:first-child { flex: 1 1 55%; min-width: 55%; }
.results-group p strong { flex: 1 1 45%; text-align: right; }
.results-group p.total {
  font-weight: 700; font-size: clamp(0.95rem, 2.6vw, 1.05rem); color: #004b95;
}
.results-group p:last-child { border: none; }

.results-group .summary {
  background-color: #f8f9fa; padding: var(--space-md);
  border-radius: 12px; font-weight: 600;
}
.results-group h4 {
  font-size: clamp(1rem, 2.8vw, 1.1rem);
  text-align: center; margin: var(--space-lg) 0 var(--space-md);
}
.partner-split-card {
  background: #f8f9fa; border: 1px solid var(--border-color);
  padding: var(--space-lg); border-radius: 12px; margin-top: var(--space-md);
}
.partner-split-card h5 { margin: 0 0 var(--space-md); font-size: clamp(0.92rem, 2.6vw, 1.02rem); }

/* Hata mesajı */
.error-message {
  text-align: center; font-weight: 600; color: #dc3545;
  background-color: #f8d7da; padding: var(--space-sm) var(--space-md);
  border-radius: 10px; margin-top: 8px;
}

/* --- Mobile tweaks --- */
@media (max-width: 480px) {
  .kdv-calculator-wrapper { padding: var(--space-md); }
  .card-header { padding: 12px 16px; }
  .card-header h2, .card-header h3 { font-size: 1.06rem; }
  .card-header p { font-size: 0.78rem; }

  .group-title { font-size: 0.9rem; }
  .radio-tile-group { gap: 10px; }
  .radio-tile { padding: 10px; border-radius: 10px; }
  .radio-tile-group.small { grid-template-columns: repeat(auto-fit, minmax(46px, 1fr)); gap: 8px; }
  .radio-tile span { font-size: 0.78rem; }
  .radio-tile small { font-size: 0.68rem; }

  #tutar-input { padding: 12px; font-size: 0.92rem; }
  .form-buttons { flex-direction: column; }
  .hesapla-button, .sifirla-button { font-size: 0.95rem; padding: 12px; }

  .results-group { padding: var(--space-lg); }
  .results-group p { font-size: 0.85rem; }
  .results-group p.total { font-size: 0.95rem; }
  .kdv-results-card .card-header h3 { font-size: 0.98rem; }
}