/* ===== CSS Custom Properties ===== */
:root {
  --primary: #00B4D8;
  --primary-dark: #0077B6;
  --primary-light: #90E0EF;
  --accent: #023E8A;
  --bg: #f8fcff;
  --bg-card: #ffffff;
  --text: #1a1a2e;
  --text-light: #555;
  --border: #e0e8f0;
  --radius: 12px;
  --shadow: 0 2px 12px rgba(0, 119, 182, 0.08);
  --shadow-hover: 0 6px 24px rgba(0, 119, 182, 0.15);
  --transition: 0.25s ease;
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

a {
  color: var(--primary-dark);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--primary);
}

/* ===== Navbar ===== */
.navbar {
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  padding: 0 2rem;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-size: 1.25rem;
  font-weight: 700;
}

.navbar-brand img {
  width: 36px;
  height: 36px;
}

.navbar-links {
  display: flex;
  gap: 1.5rem;
  list-style: none;
}

.navbar-links a {
  color: rgba(255, 255, 255, 0.85);
  font-weight: 500;
  padding: 0.4rem 0.8rem;
  border-radius: 6px;
  transition: all var(--transition);
}

.navbar-links a:hover,
.navbar-links a.active {
  color: #fff;
  background: rgba(255, 255, 255, 0.15);
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 6px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: #fff;
  margin: 5px 0;
  border-radius: 2px;
  transition: all var(--transition);
}

/* ===== Hero ===== */
.hero {
  background: linear-gradient(160deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
  color: #fff;
  text-align: center;
  padding: 4rem 2rem;
}

.hero-logo {
  width: 120px;
  height: 120px;
  margin-bottom: 1.5rem;
}

.hero h1 {
  font-size: 2.5rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.hero p {
  font-size: 1.15rem;
  opacity: 0.9;
  max-width: 600px;
  margin: 0 auto 2rem;
}

.hero-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  background: #fff;
  color: var(--primary-dark);
  font-size: 1.1rem;
  font-weight: 700;
  padding: 0.85rem 2rem;
  border-radius: 50px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.15);
  transition: all var(--transition);
}

.hero-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
  color: var(--primary-dark);
}

/* Hero compact variant */
.hero-compact {
  padding: 2.5rem 2rem;
}

.badge-windows {
  display: inline-block;
  background: rgba(255, 255, 255, 0.2);
  border: 1px solid rgba(255, 255, 255, 0.4);
  color: #fff;
  font-size: 0.85rem;
  font-weight: 600;
  padding: 0.3rem 1rem;
  border-radius: 20px;
  margin-top: 1rem;
}

/* Download grid centered (single card) */
.download-grid-center {
  max-width: 300px;
  margin: 0 auto;
}

/* ===== Sections ===== */
.section {
  padding: 3.5rem 2rem;
  max-width: 1100px;
  margin: 0 auto;
  width: 100%;
}

.section-title {
  font-size: 1.75rem;
  font-weight: 700;
  color: var(--primary-dark);
  margin-bottom: 0.5rem;
  text-align: center;
}

.section-subtitle {
  text-align: center;
  color: var(--text-light);
  margin-bottom: 2.5rem;
}

/* ===== Download Cards ===== */
.download-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
}

.download-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 1.5rem;
  text-align: center;
  box-shadow: var(--shadow);
  transition: all var(--transition);
  position: relative;
}

.download-card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
}

.download-card.recommended {
  border-color: var(--primary);
  box-shadow: 0 2px 12px rgba(0, 180, 216, 0.2);
}

.download-card.recommended::before {
  content: 'Önerilen';
  position: absolute;
  top: -10px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--primary);
  color: #fff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 2px 12px;
  border-radius: 10px;
}

.download-card .platform-icon {
  font-size: 2rem;
  margin-bottom: 0.75rem;
}

.download-card h3 {
  font-size: 1.05rem;
  margin-bottom: 0.25rem;
}

.download-card .file-info {
  font-size: 0.85rem;
  color: var(--text-light);
  margin-bottom: 1rem;
}

.download-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  font-weight: 600;
  padding: 0.6rem 1.5rem;
  border-radius: 8px;
  font-size: 0.95rem;
  transition: all var(--transition);
}

.download-btn:hover {
  color: #fff;
  opacity: 0.9;
  transform: translateY(-1px);
}

/* ===== Steps Flow ===== */
.steps-flow {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: 0;
}

.flow-step {
  flex: 1;
  max-width: 200px;
  text-align: center;
  padding: 0 0.5rem;
}

.flow-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 1rem;
  background: linear-gradient(135deg, var(--primary-dark), var(--primary));
  color: #fff;
  font-size: 1.5rem;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0, 119, 182, 0.3);
  transition: all var(--transition);
}

.flow-step:hover .flow-icon {
  transform: scale(1.1);
  box-shadow: 0 6px 24px rgba(0, 119, 182, 0.4);
}

.flow-step h3 {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.3rem;
  color: var(--primary-dark);
}

.flow-step p {
  font-size: 0.85rem;
  color: var(--text-light);
  line-height: 1.4;
}

.flow-arrow {
  display: flex;
  align-items: center;
  font-size: 1.5rem;
  color: var(--primary);
  padding-top: 1.2rem;
  flex-shrink: 0;
}

/* Mobile: vertical flow */
@media (max-width: 768px) {
  .steps-flow {
    flex-direction: column;
    align-items: center;
    gap: 0;
  }

  .flow-step {
    max-width: 280px;
  }

  .flow-arrow {
    transform: rotate(90deg);
    padding: 0.5rem 0;
  }
}

/* ===== Usage Info ===== */
.usage-box {
  background: linear-gradient(135deg, #e8f8ff, #f0f4ff);
  border: 1px solid var(--primary-light);
  border-radius: var(--radius);
  padding: 2rem;
  text-align: center;
}

.usage-box p {
  font-size: 1.05rem;
  max-width: 700px;
  margin: 0 auto;
}

/* ===== Test Page - iframe ===== */
.iframe-container {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow);
  min-height: 500px;
  position: relative;
}

.iframe-container iframe {
  width: 100%;
  height: 600px;
  border: none;
  display: block;
}

.iframe-error {
  display: none;
  padding: 3rem 2rem;
  text-align: center;
}

.iframe-error.visible {
  display: block;
}

.iframe-error .error-icon {
  font-size: 3rem;
  margin-bottom: 1rem;
}

.iframe-error h3 {
  color: var(--primary-dark);
  margin-bottom: 0.75rem;
  font-size: 1.3rem;
}

.iframe-error p {
  color: var(--text-light);
  max-width: 500px;
  margin: 0 auto 1rem;
}

.iframe-error .error-details {
  background: #fff5f5;
  border: 1px solid #fecaca;
  border-radius: 8px;
  padding: 1rem;
  font-size: 0.9rem;
  color: #b91c1c;
  max-width: 500px;
  margin: 0 auto;
}

.iframe-loading {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg-card);
}

.iframe-loading .spinner {
  width: 40px;
  height: 40px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

@keyframes spin {
  to { transform: rotate(360deg); }
}

/* ===== Footer ===== */
.footer {
  background: var(--accent);
  color: rgba(255, 255, 255, 0.7);
  text-align: center;
  padding: 2rem 2rem 1.5rem;
  font-size: 0.9rem;
  margin-top: auto;
}

.footer-brand {
  color: #fff;
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.6rem;
}

.footer-contact {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  flex-wrap: wrap;
  margin-bottom: 0.5rem;
}

.footer-contact a {
  color: var(--primary-light);
}

.footer-contact a:hover {
  color: #fff;
}

.footer-address {
  margin-bottom: 0.75rem;
  font-size: 0.85rem;
}

.footer-links {
  display: flex;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.8rem;
  opacity: 0.7;
}

.footer-links a {
  color: var(--primary-light);
}

.footer-links a:hover {
  color: #fff;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .navbar {
    padding: 0 1rem;
  }

  .nav-toggle {
    display: block;
  }

  .navbar-links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--primary-dark);
    padding: 1rem;
    gap: 0.5rem;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
  }

  .navbar-links.open {
    display: flex;
  }

  .navbar-links a {
    padding: 0.6rem 1rem;
  }

  .hero {
    padding: 3rem 1.5rem;
  }

  .hero h1 {
    font-size: 1.75rem;
  }

  .hero p {
    font-size: 1rem;
  }

  .hero-logo {
    width: 90px;
    height: 90px;
  }

  .section {
    padding: 2.5rem 1rem;
  }

  .section-title {
    font-size: 1.4rem;
  }

  .download-grid {
    grid-template-columns: 1fr;
  }

  .iframe-container iframe {
    height: 400px;
  }
}

@media (min-width: 769px) and (max-width: 1024px) {
  .download-grid {
    grid-template-columns: repeat(2, 1fr);
  }

}