:root {
  --renk-ana: #2563eb;
  --renk-ana-koyu: #1d4ed8;
  --renk-arkaplan: #f8fafc;
  --renk-yazi: #1e293b;
  --renk-yazi-soluk: #64748b;
  --renk-kenarlik: #e2e8f0;
  --renk-kart: #ffffff;
  --renk-basari: #16a34a;
  --renk-hata: #dc2626;
  --renk-sonuc-bg: #eff6ff;
  --renk-sonuc-kenarlik: #bfdbfe;
  --renk-input-bg: #ffffff;
  --renk-cikti-bg: #f8fafc;
  --radius: 10px;
}

:root[data-theme="dark"] {
  --renk-ana: #3b82f6;
  --renk-ana-koyu: #60a5fa;
  --renk-arkaplan: #0f172a;
  --renk-yazi: #e2e8f0;
  --renk-yazi-soluk: #94a3b8;
  --renk-kenarlik: #334155;
  --renk-kart: #1e293b;
  --renk-basari: #4ade80;
  --renk-hata: #f87171;
  --renk-sonuc-bg: #1e3a5f;
  --renk-sonuc-kenarlik: #2c5282;
  --renk-input-bg: #0f172a;
  --renk-cikti-bg: #0f172a;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: var(--renk-arkaplan);
  color: var(--renk-yazi);
  line-height: 1.5;
}

a {
  color: var(--renk-ana);
  text-decoration: none;
}

a:hover {
  text-decoration: underline;
}

/* Header */
.site-header {
  background: var(--renk-kart);
  border-bottom: 1px solid var(--renk-kenarlik);
}

.site-header .icerik {
  max-width: 960px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.site-header .logo {
  font-weight: 700;
  font-size: 1.2rem;
  color: var(--renk-yazi);
}

.site-header .logo:hover {
  text-decoration: none;
}

.site-header nav a {
  margin-left: 18px;
  color: var(--renk-yazi-soluk);
  font-size: 0.95rem;
}

.site-header nav {
  display: flex;
  align-items: center;
}

.tema-buton {
  width: auto;
  margin-left: 18px;
  padding: 6px 10px;
  background: transparent;
  border: 1px solid var(--renk-kenarlik);
  border-radius: 8px;
  font-size: 1rem;
  line-height: 1;
  cursor: pointer;
}

.tema-buton:hover {
  background: var(--renk-arkaplan);
}

/* Ana içerik */
main {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

.arac-kart {
  background: var(--renk-kart);
  border: 1px solid var(--renk-kenarlik);
  border-radius: var(--radius);
  padding: 28px;
  max-width: 560px;
  margin: 0 auto;
}

h1 {
  font-size: 1.6rem;
  margin-top: 0;
}

.aciklama {
  color: var(--renk-yazi-soluk);
  margin-bottom: 24px;
}

label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 0.95rem;
}

input, select {
  width: 100%;
  padding: 10px 12px;
  border: 1px solid var(--renk-kenarlik);
  border-radius: 8px;
  font-size: 1rem;
  margin-bottom: 16px;
  background: var(--renk-input-bg);
  color: var(--renk-yazi);
}

input:focus, select:focus {
  outline: none;
  border-color: var(--renk-ana);
}

button {
  background: var(--renk-ana);
  color: #fff;
  border: none;
  padding: 12px 20px;
  border-radius: 8px;
  font-size: 1rem;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
}

button:hover {
  background: var(--renk-ana-koyu);
}

.sonuc {
  margin-top: 20px;
  padding: 18px;
  border-radius: 8px;
  background: var(--renk-sonuc-bg);
  border: 1px solid var(--renk-sonuc-kenarlik);
  display: none;
}

.sonuc.gorunur {
  display: block;
}

.sonuc-satir {
  display: flex;
  justify-content: space-between;
  padding: 6px 0;
  font-size: 0.95rem;
}

.sonuc-satir.vurgu {
  font-weight: 700;
  font-size: 1.1rem;
  border-top: 1px solid var(--renk-sonuc-kenarlik);
  margin-top: 6px;
  padding-top: 12px;
}

.hata-mesaji {
  color: var(--renk-hata);
  font-size: 0.9rem;
  margin: -10px 0 16px;
  display: none;
}

.hata-mesaji.gorunur {
  display: block;
}

/* Ana sayfa araç listesi */
.arac-listesi {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: 16px;
}

.arac-linki {
  background: var(--renk-kart);
  border: 1px solid var(--renk-kenarlik);
  border-radius: var(--radius);
  padding: 20px;
  display: block;
  color: var(--renk-yazi);
}

.arac-linki:hover {
  border-color: var(--renk-ana);
  text-decoration: none;
}

.arac-linki .baslik {
  font-weight: 700;
  margin-bottom: 4px;
}

.arac-linki .aciklama {
  font-size: 0.9rem;
  margin-bottom: 0;
}

/* Footer */
.site-footer {
  border-top: 1px solid var(--renk-kenarlik);
  padding: 24px 20px;
  text-align: center;
  color: var(--renk-yazi-soluk);
  font-size: 0.9rem;
}

/* Mobil uyum */
@media (max-width: 600px) {
  .site-header .icerik {
    flex-direction: column;
    gap: 10px;
    padding: 14px 16px;
  }

  .site-header nav a {
    margin: 0 9px;
  }

  main {
    padding: 20px 14px 40px;
  }

  .arac-kart {
    padding: 20px;
    max-width: 100%;
  }

  h1 {
    font-size: 1.35rem;
  }

  input, select, button {
    font-size: 16px; /* iOS'ta otomatik zoom'u engeller */
  }

  .arac-listesi {
    grid-template-columns: 1fr;
  }
}