/**
 * Professional Dynamic Personal Portfolio Styling
 * Modern CSS3 with CSS Custom Variables, Dual Light/Dark Theme & Smooth Animations
 */

:root {
  --font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
  --font-serif: 'Playfair Display', Georgia, serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Light Theme Colors */
  --bg-main: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --border-color: #e2e8f0;
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #64748b;
  --accent-primary: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-glow: rgba(37, 99, 235, 0.15);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

.dark {
  /* Dark Theme Colors */
  --bg-main: #090d16;
  --bg-card: #0f172a;
  --bg-card-hover: #1e293b;
  --border-color: #1e293b;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-primary: #3b82f6;
  --accent-hover: #60a5fa;
  --accent-glow: rgba(59, 130, 246, 0.2);
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.5);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.5);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-main);
  color: var(--text-primary);
  transition: background-color 0.3s ease, color 0.3s ease;
  overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Typography Helpers */
.font-serif {
  font-family: var(--font-serif);
}
.font-mono {
  font-family: var(--font-mono);
}

/* Card Styling */
.portfolio-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 1rem;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  overflow: hidden;
}

.portfolio-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-primary);
  box-shadow: var(--shadow-lg), 0 0 20px var(--accent-glow);
}

/* Image Frame Containers */
.img-frame {
  position: relative;
  overflow: hidden;
  background-color: var(--bg-card-hover);
}

.img-frame img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.5s ease;
}

.portfolio-card:hover .img-frame img {
  transform: scale(1.05);
}

/* Buttons */
.btn-accent {
  background-color: var(--accent-primary);
  color: #ffffff;
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: 0.5rem;
  transition: all 0.2s ease;
  border: none;
}

.btn-accent:hover {
  background-color: var(--accent-hover);
  color: #ffffff;
  transform: translateY(-1px);
  box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-outline-custom {
  background-color: transparent;
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  font-weight: 600;
  padding: 0.65rem 1.4rem;
  border-radius: 0.5rem;
  transition: all 0.2s ease;
}

.btn-outline-custom:hover {
  border-color: var(--accent-primary);
  color: var(--accent-primary);
  background-color: var(--accent-glow);
}

/* Category Filter Tabs (Zero-Pill discipline: clean segmented buttons) */
.filter-tabs {
  display: flex;
  gap: 0.5rem;
  flex-wrap: wrap;
  padding: 0.25rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: 0.75rem;
}

.filter-btn {
  padding: 0.5rem 1.25rem;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--text-secondary);
  border: none;
  background: transparent;
  border-radius: 0.5rem;
  transition: all 0.2s ease;
  cursor: pointer;
}

.filter-btn.active, .filter-btn:hover {
  color: var(--text-primary);
  background-color: var(--bg-card-hover);
}

.filter-btn.active {
  font-weight: 600;
  box-shadow: var(--shadow-sm);
  border: 1px solid var(--border-color);
}

/* Metadata Unboxed Text */
.meta-unboxed {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.8125rem;
  color: var(--text-muted);
}

.meta-separator {
  opacity: 0.5;
}

/* Back to Top Button */
#backToTop {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  width: 45px;
  height: 45px;
  border-radius: 50%;
  background-color: var(--accent-primary);
  color: #ffffff;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: var(--shadow-md);
  opacity: 0;
  visibility: hidden;
  transition: all 0.3s ease;
  z-index: 99;
  border: none;
}

#backToTop.show {
  opacity: 1;
  visibility: visible;
}

#backToTop:hover {
  transform: translateY(-3px);
  background-color: var(--accent-hover);
}