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

:root {
  --primary-color: #2c3e50;
  --accent-color: #3498db;
  --accent-hover: #2980b9;
  --bg-gradient-start: #1a2a3a;
  --bg-gradient-end: #2c3e50;
  --text-light: #ecf0f1;
  --card-bg: #ffffff;
  --shadow: rgba(0, 0, 0, 0.25);
}

body {
  font-family:
    -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, var(--bg-gradient-start) 0%, var(--bg-gradient-end) 100%);
  min-height: 100vh;
  color: var(--text-light);
  display: flex;
  flex-direction: column;
}

header {
  text-align: center;
  padding: 2rem 1rem 1.5rem;
  background: rgba(0, 0, 0, 0.2);
  border-bottom: 3px solid var(--accent-color);
  box-shadow: 0 2px 10px var(--shadow);
}

header h1 {
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  margin-bottom: 0.5rem;
  background: linear-gradient(90deg, #3498db, #2ecc71);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: 700;
}

header .subtitle {
  font-size: clamp(0.9rem, 2vw, 1.2rem);
  color: #bdc3c7;
  font-style: italic;
  max-width: 800px;
  margin: 0 auto;
}

.badges {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
  margin-top: 1rem;
}

.badges a img {
  height: 20px;
  vertical-align: middle;
}

.toolbar {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 1rem;
  padding: 1rem;
  flex-wrap: wrap;
  background: rgba(0, 0, 0, 0.15);
}

.toolbar a {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  text-decoration: none;
  color: var(--text-light);
  background: var(--accent-color);
  padding: 0.6rem 1.2rem;
  border-radius: 8px;
  font-weight: 600;
  transition: all 0.25s ease;
  box-shadow: 0 2px 6px var(--shadow);
}

.toolbar a:hover {
  background: var(--accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px var(--shadow);
}

.toolbar a.secondary {
  background: transparent;
  border: 2px solid var(--accent-color);
}

.toolbar a.secondary:hover {
  background: var(--accent-color);
}

.pdf-container {
  flex: 1;
  display: flex;
  justify-content: center;
  padding: 1.5rem;
  width: 100%;
}

.pdf-frame-wrapper {
  width: 100%;
  max-width: 1100px;
  background: var(--card-bg);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 10px 40px var(--shadow);
  display: flex;
  flex-direction: column;
  min-height: 75vh;
}

.pdf-frame-header {
  background: var(--primary-color);
  color: var(--text-light);
  padding: 0.75rem 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
  font-weight: 600;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.pdf-frame-header .dot {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  display: inline-block;
}

.dot.red {
  background: #e74c3c;
}
.dot.yellow {
  background: #f1c40f;
}
.dot.green {
  background: #2ecc71;
}

.pdf-frame-header .filename {
  margin-left: 0.75rem;
  opacity: 0.85;
}

.pdf-embed {
  flex: 1;
  width: 100%;
  border: none;
  min-height: 70vh;
  background: #525659;
}

.pdf-fallback {
  padding: 2rem;
  text-align: center;
  color: var(--primary-color);
}

.pdf-fallback a {
  color: var(--accent-color);
  font-weight: 600;
}

footer {
  text-align: center;
  padding: 1.25rem;
  font-size: 0.85rem;
  color: #95a5a6;
  background: rgba(0, 0, 0, 0.2);
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

footer a {
  color: var(--accent-color);
  text-decoration: none;
}

footer a:hover {
  text-decoration: underline;
}

@media (max-width: 600px) {
  .pdf-frame-wrapper {
    min-height: 60vh;
  }
  .pdf-embed {
    min-height: 55vh;
  }
}