/* 
  E-Book Tools Hub - Base CSS (Minimal & High Performance) 
  Standard CSS used for maximum compatibility and speed.
*/

:root {
  --primary-h: 217;
  --primary-s: 91%;
  --primary-l: 60%;
  --primary: hsl(var(--primary-h), var(--primary-s), var(--primary-l));
  --primary-hover: hsl(var(--primary-h), var(--primary-s), 50%);
  
  --bg-body: #f8fafc;
  --bg-card: #ffffff;
  --text-main: #0f172a;
  --text-dim: #64748b;
  --border: #e2e8f0;
  --border-light: #f1f5f9;
  
  --success: #10b981;
  --warning: #f59e0b;
  --error: #ef4444;
  --radius: 12px;
}

[data-theme="dark"] {
  --bg-body: #0f172a;
  --bg-card: #1e293b;
  --text-main: #f1f5f9;
  --text-dim: #94a3b8;
  --border: #334155;
  --border-light: #1e293b;
}

body {
  font-family: 'Sarabun', sans-serif;
  background-color: var(--bg-body);
  color: var(--text-main);
  transition: background-color 0.2s, color 0.2s;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Glassmorphism */
.glass {
  background: rgba(255, 255, 255, 0.7);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

[data-theme="dark"] .glass {
  background: rgba(15, 23, 42, 0.7);
  border: 1px solid rgba(51, 65, 85, 0.3);
}

/* Module Cards */
.module-card {
  background-color: var(--bg-card);
  border-radius: var(--radius);
  padding: 1.5rem;
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  height: 100%;
  transition: all 0.3s ease;
  cursor: pointer;
  text-decoration: none;
  color: inherit;
}

.module-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 10px 25px -5px hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.15);
  border-color: hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.3);
}

/* Standard Header */
.header-nav {
  background-color: hsla(0, 0%, 100%, 0.8);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
  padding: 1rem 1.5rem;
  position: sticky;
  top: 0;
  z-index: 50;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

[data-theme="dark"] .header-nav {
  background-color: hsla(222, 47%, 11%, 0.8);
}

/* Icon Buttons */
.btn-icon {
  width: 2.25rem;
  height: 2.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 0.5rem;
  border: 1px solid var(--border);
  background: transparent;
  color: var(--text-dim);
  cursor: pointer;
  transition: all 0.2s;
}

.btn-icon:hover {
  color: var(--primary);
  border-color: var(--primary);
  background-color: var(--border-light);
}

/* Primary Button */
.btn-primary {
  background-color: var(--primary);
  color: white;
  font-weight: 600;
  padding: 0.625rem 1.5rem;
  border-radius: 0.5rem;
  border: none;
  cursor: pointer;
  transition: all 0.2s;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.05);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
}

.btn-primary:active {
  transform: scale(0.98);
}

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* Scrollbar Polish */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { 
  background: var(--border); 
  border-radius: 10px; 
}
::-webkit-scrollbar-thumb:hover { 
  background: hsla(var(--primary-h), var(--primary-s), var(--primary-l), 0.3); 
}

/* Uploaded state for drag & drop zone */
.is-uploaded {
  border-color: var(--success) !important;
  background-color: rgba(16, 185, 129, 0.05) !important;
}
[data-theme="dark"] .is-uploaded {
  background-color: rgba(16, 185, 129, 0.1) !important;
}