:root {
  --navy: #0A1F44;
  --dark-navy: #001f3f;
  --orange: #FF6B00;
  --white: #ffffff;
  --light-gray: #f8f9fa;
  --gray: #6c757d;
}

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

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--navy);
  background: linear-gradient(135deg, var(--navy) 0%, var(--dark-navy) 100%);
  min-height: 100vh;
}

.site-header {
  background: rgba(255,255,255,0.95);
  backdrop-filter: blur(10px);
  box-shadow: 0 2px 20px rgba(0,0,0,0.1);
  position: sticky;
  top: 0;
  z-index: 100;
}

.dashboard-btn {
  background: var(--orange, #ff6b35);
  color: white;
  padding: 10px 20px;
  border-radius: 25px;
  text-decoration: none;
  font-weight: bold;
  transition: all 0.3s;
}

.dashboard-btn:hover {
  background: #e55a2b;
  transform: translateY(-2px);
}

.header-inner {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.brand {
  display: flex;
  align-items: center;
  text-decoration: none;
  color: var(--navy);
  font-weight: bold;
  font-size: 1.2rem;
}

.brand img {
  width: 40px;
  height: 40px;
  margin-right: 0.5rem;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--navy);
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 2rem;
}

.auth-section {
  text-align: center;
  color: white;
  padding: 4rem 0;
}

.auth-section h1 {
  font-size: 3rem;
  background: linear-gradient(135deg, white, var(--orange));
  -webkit-background-clip: text;
  background-clip: text;
  margin-bottom: 1rem;
}

.auth-section p {
  font-size: 1.2rem;
  opacity: 0.9;
}

.library-content {
  background: white;
  border-radius: 20px;
  padding: 2.5rem;
  box-shadow: 0 20px 40px rgba(0,0,0,0.2);
  margin-top: 2rem;
}

.hidden {
  display: none;
}

.file-controls {
  margin-bottom: 2rem;
}

.file-controls h2 {
  color: var(--navy);
  margin-bottom: 1rem;
}

.controls {
  display: flex;
  gap: 1rem;
  margin-bottom: 1rem;
}

.controls input, .controls select {
  padding: 0.75rem;
  border: 2px solid #e9ecef;
  border-radius: 8px;
  font-size: 1rem;
}

#userName {
  color: var(--orange);
}

.file-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 1.5rem;
  margin-bottom: 3rem;
}

.file-card {
  background: var(--light-gray);
  border: 2px solid #e9ecef;
  border-radius: 12px;
  padding: 1.5rem;
  transition: all 0.3s;
  cursor: pointer;
}

.file-card:hover {
  border-color: var(--orange);
  box-shadow: 0 10px 25px rgba(255,107,0,0.15);
  transform: translateY(-5px);
}

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

.file-name {
  font-weight: bold;
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
  color: var(--navy);
}

.file-meta {
  font-size: 0.9rem;
  color: var(--gray);
  margin-bottom: 1rem;
}

.download-btn {
  background: var(--orange);
  color: white;
  border: none;
  padding: 0.5rem 1rem;
  border-radius: 6px;
  cursor: pointer;
  font-size: 0.9rem;
  width: 100%;
  transition: background 0.3s;
}

.download-btn:hover {
  background: #e55a2b;
}

.preview-btn {
  background: #3b82f6;
  color: white;
}

.preview-btn:hover {
  background: #2563eb;
}

.upload-area {
  border-top: 2px dashed #dee2e6;
  padding-top: 2rem;
  text-align: center;
}

.upload-area h3 {
  color: var(--navy);
  margin-bottom: 1rem;
}

#fileUpload {
  display: block;
  margin: 0 auto 1rem;
  padding: 0.75rem;
}

#uploadBtn {
  background: var(--orange);
  color: white;
  border: none;
  padding: 0.75rem 2rem;
  border-radius: 8px;
  cursor: pointer;
  font-size: 1rem;
}

.upload-note {
  color: var(--gray);
  font-size: 0.9rem;
  margin-top: 1rem;
}

footer {
  text-align: center;
  padding: 2rem;
  color: white;
  opacity: 0.8;
}

@media (max-width: 768px) {
  .container {
    padding: 1rem;
  }

  .controls {
    flex-direction: column;
  }

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

  .auth-section h1 {
    font-size: 2rem;
  }

  .menu-toggle {
    display: block;
  }
}

.file-card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.preview-btn {
    background: #3b82f6 !important;
}

.preview-btn:hover {
    background: #2563eb !important;
}