:root {
  --primary: #22c55e;
  --dark: #1f2937;
  --light: #f9fafb;
  --gray: #6b7280;
  --max-width: 1000px;
}

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

body {
  font-family: 'Segoe UI', sans-serif;
  background-color: var(--light);
  color: var(--dark);
  line-height: 1.6;
  padding: 0;
  margin: 0;
}

header {
  background: white;
  padding: 1rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  position: sticky;
  top: 0;
  z-index: 1000;
  box-shadow: 0 1px 4px rgba(0,0,0,0.1);
}

header h1 {
  font-size: 1.5rem;
  color: var(--primary);
}

nav {
  display: flex;
  gap: 1rem;
  align-items: center;
  flex-wrap: wrap;
}

nav a,
nav select {
  text-decoration: none;
  color: var(--gray);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem;
  border-radius: 5px;
  transition: all 0.2s ease;
}

nav a:hover,
nav a.active {
  background: var(--primary);
  color: white;
}

.container {
  max-width: var(--max-width);
  margin: 1.5rem auto;
  padding: 0 1rem;
}

.card {
  background: white;
  padding: 1rem;
  border-radius: 8px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
  margin-bottom: 1.5rem;
}

.flex {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.btn {
  background: var(--primary);
  color: white;
  padding: 0.5rem 1rem;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-weight: bold;
  transition: background 0.3s ease;
}

.btn:hover {
  background: #16a34a;
}

table {
  width: 100%;
  border-collapse: collapse;
  margin-top: 1rem;
  background: white;
  border-radius: 8px;
  overflow: hidden;
  box-shadow: 0 2px 6px rgba(0,0,0,0.05);
}

table th,
table td {
  padding: 0.75rem;
  text-align: left;
  border-bottom: 1px solid #eee;
}

table th {
  background: #f3f4f6;
}

h2, h3 {
  color: var(--primary);
  margin-top: 1rem;
  margin-bottom: 0.5rem;
}

hr {
  margin: 2rem 0;
  border: 0;
  border-top: 1px solid #eee;
}

code {
  background: #f3f4f6;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  font-family: monospace;
}

/* Mobil Uyum */
@media (max-width: 768px) {
  nav {
    flex-direction: column;
    align-items: flex-start;
  }

  .flex {
    flex-direction: column;
  }

  table thead {
    display: none;
  }

  table tr {
    display: block;
    margin-bottom: 1rem;
    border: 1px solid #eee;
    border-radius: 8px;
    padding: 1rem;
  }

  table td {
    display: flex;
    justify-content: space-between;
    padding: 0.5rem 0;
    border-bottom: none;
  }

  table td::before {
    content: attr(data-label);
    font-weight: bold;
    color: var(--gray);
  }
}