:root {
  --bg: #525252;
  --card-bg: #2a3748;
  --text: #eef2f6;
  --primary: #ff7a2f;
  --border: #3e4b5d;
  --input-bg: #1e2a3a;
  --input-text: #eef2f6;
  --shadow: rgba(0, 0, 0, 0.3);
}

body.light {
  --bg: #f0f4fa;
  --card-bg: #ffffff;
  --text: #1e2a3a;
  --primary: #ff7a2f;
  --border: #d0d9e6;
  --input-bg: #ffffff;
  --input-text: #1e2a3a;
  --shadow: rgba(0, 0, 0, 0.05);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: 'Segoe UI', Roboto, sans-serif;
  background: var(--bg);
  color: var(--text);
  transition: background 0.3s, color 0.2s;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 20px 15px;
  font-size: 14px;
}

/* ---------- BAŞLIK ALANI ---------- */
.header-logo {
  width: 100%;
  max-width: 1400px;
  display: flex;
  align-items: center;
  gap: 15px;
  margin: 0 0 30px 0;
  padding: 0 10px;
}
.header-logo .logo {
  height: 55px;
  width: auto;
  border-radius: 12px; /* yuvarlak köşeler */
  object-fit: contain;
}
.header-text {
  display: flex;
  flex-direction: column;
}
.ana-baslik {
  font-size: 26px;
  font-weight: 700;
  color: var(--primary);
  line-height: 1.2;
  letter-spacing: 0.5px;
}
.alt-baslik {
  font-size: 14px;
  color: var(--text);
  opacity: 0.8;
  margin-top: 2px;
}
@media (max-width: 650px) {
  .header-logo .logo { height: 40px; }
  .ana-baslik { font-size: 20px; }
  .alt-baslik { font-size: 12px; }
}

/* tema butonu */
.theme-toggle {
  position: fixed;
  top: 20px;
  right: 80px;
  background: var(--primary);
  border: none;
  color: white;
  padding: 8px 16px;
  border-radius: 30px;
  font-size: 14px;
  cursor: pointer;
  z-index: 999;
  box-shadow: 0 4px 8px var(--shadow);
  transition: 0.2s;
  white-space: nowrap;
  max-width: 120px;
  width: auto;
  min-width: 70px;
  text-align: center;
}
.theme-toggle:hover {
  filter: brightness(1.1);
  transform: scale(1.02);
}

/* çıkış simgesi */
.cikis-simgesi {
  position: fixed;
  top: 20px;
  right: 20px;
  cursor: pointer;
  z-index: 1000;
  background: var(--card-bg);
  border-radius: 30px;
  padding: 5px 12px;
  box-shadow: 0 4px 8px var(--shadow);
  transition: 0.2s;
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--text);
  font-size: 13px;
}
.cikis-simgesi:hover {
  transform: scale(1.05);
  background: var(--primary);
  color: white;
}
.cikis-simgesi img {
  width: 24px;
  height: auto;
}

/* kart grid */
.card-container {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(290px, 1fr));
  gap: 22px;
  width: 100%;
  max-width: 1400px;
  margin-top: 10px;
}

/* kart */
.card {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 18px 16px 16px 16px;
  box-shadow: 0 8px 18px var(--shadow);
  transition: transform 0.2s, box-shadow 0.2s;
  display: flex;
  flex-direction: column;
  gap: 12px;
  backdrop-filter: blur(2px);
}
.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 15px 25px var(--shadow);
}

/* bilgi ikonu */
.info-icon {
  position: absolute;
  top: 12px;
  left: 12px;
  font-size: 18px;
  cursor: pointer;
  background: var(--primary);
  color: white;
  width: 28px;
  height: 28px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 2px 6px black;
  z-index: 10; /* overlay'in altında kalmaması için yüksek */
}

/* kart başlığı */
.card h2 {
  font-size: 16px;
  margin: 0 0 4px 0;
  color: var(--primary);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-left: 36px;
  min-height: 36px;
}
.card-link {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px dashed var(--primary);
  font-weight: 500;
  font-size: 13px;
  margin-left: auto;
}
.card-link:hover {
  color: var(--primary);
}

/* açıklama overlay */
.aciklama-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--card-bg);
  backdrop-filter: blur(4px);
  display: none; /* varsayılan gizli */
  flex-direction: column;
  justify-content: center;
  align-items: center;
  padding: 20px;
  z-index: 20; /* ikonun üstünde */
  border-radius: 20px;
  box-sizing: border-box;
  border: 2px solid var(--primary);
}
.aciklama-icerik {
  text-align: center;
  font-size: 13px;
  line-height: 1.5;
  color: var(--text);
}
.aciklama-icerik button {
  margin-top: 18px;
  padding: 8px 18px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 30px;
  cursor: pointer;
  font-weight: 600;
}

/* inputlar */
input {
  width: 100%;
  padding: 10px 12px;
  border-radius: 16px;
  border: 1px solid var(--border);
  background: var(--input-bg);
  color: var(--input-text);
  font-size: 13px;
  outline: none;
  transition: 0.2s;
}
input:focus {
  border-color: var(--primary);
  box-shadow: 0 0 0 2px rgba(255, 122, 47, 0.2);
}
input::placeholder {
  color: #9aa9b9;
  opacity: 0.7;
}

/* butonlar */
button {
  width: 100%;
  padding: 10px;
  border-radius: 30px;
  border: none;
  background: var(--primary);
  color: white;
  font-weight: 600;
  font-size: 13px;
  cursor: pointer;
  transition: 0.2s;
  box-shadow: 0 4px 6px var(--shadow);
}
button:hover {
  filter: brightness(1.1);
  transform: scale(1.02);
}
button.temizle {
  background: #6c757d;
  margin-top: 0;
}
button.temizle:hover {
  background: #5a6268;
}

/* sonuç */
.result {
  min-height: 65px;
  background: rgba(0,0,0,0.1);
  border-radius: 16px;
  padding: 10px;
  font-weight: 500;
  font-size: 13px;
  white-space: pre-line;
  border: 1px solid var(--border);
  color: var(--text);
}

/* mobil */
@media (max-width: 650px) {
  body { padding: 10px; }
  .theme-toggle { 
    right: 90px; 
    top: 15px; 
    padding: 6px 12px;
    max-width: 100px; 
  }
  .cikis-simgesi { top: 15px; right: 15px; padding: 4px 10px; }
  .card-container { gap: 16px; }
  .card { padding: 16px; }
  .card h2 { padding-left: 32px; }
}