/* ==========================================================================
   Dr. Faizan Salam - Academic Portfolio Design System
   Modern CSS with Dark/Light Mode, Glassmorphism, and Fluid Typography
   ========================================================================== */

:root {
  /* Color Palette - Dark Theme (Default) */
  --bg-primary: #0a0e17;
  --bg-secondary: #111827;
  --bg-card: rgba(17, 24, 39, 0.75);
  --bg-card-hover: rgba(30, 41, 59, 0.85);
  --bg-glass: rgba(15, 23, 42, 0.65);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-accent: rgba(56, 189, 248, 0.3);
  
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-primary: #38bdf8;       /* Sky Blue */
  --accent-secondary: #2dd4bf;     /* Teal */
  --accent-gradient: linear-gradient(135deg, #38bdf8 0%, #2dd4bf 100%);
  --accent-glow: rgba(56, 189, 248, 0.15);
  
  --tag-bg: rgba(56, 189, 248, 0.1);
  --tag-border: rgba(56, 189, 248, 0.25);
  --tag-text: #7dd3fc;

  --badge-green-bg: rgba(34, 197, 94, 0.12);
  --badge-green-text: #4ade80;
  --badge-green-border: rgba(34, 197, 94, 0.3);

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;
  
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.2), 0 2px 4px -2px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 10px 25px -3px rgba(0, 0, 0, 0.3), 0 4px 6px -4px rgba(0, 0, 0, 0.3);
  --shadow-glow: 0 0 30px rgba(56, 189, 248, 0.15);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-full: 9999px;
  
  --container-max: 1180px;
}

[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #ffffff;
  --bg-card: rgba(255, 255, 255, 0.85);
  --bg-card-hover: #ffffff;
  --bg-glass: rgba(255, 255, 255, 0.75);
  --border-color: rgba(15, 23, 42, 0.08);
  --border-accent: rgba(2, 132, 199, 0.35);
  
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  
  --accent-primary: #0284c7;
  --accent-secondary: #0d9488;
  --accent-gradient: linear-gradient(135deg, #0284c7 0%, #0d9488 100%);
  --accent-glow: rgba(2, 132, 199, 0.12);
  
  --tag-bg: rgba(2, 132, 199, 0.08);
  --tag-border: rgba(2, 132, 199, 0.2);
  --tag-text: #0369a1;

  --badge-green-bg: rgba(22, 163, 74, 0.1);
  --badge-green-text: #15803d;
  --badge-green-border: rgba(22, 163, 74, 0.25);
  
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.06);
  --shadow-lg: 0 12px 30px rgba(15, 23, 42, 0.08);
  --shadow-glow: 0 0 25px rgba(2, 132, 199, 0.1);
}

/* ==========================================================================
   Base Styles
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  background-image: 
    radial-gradient(at 0% 0%, rgba(56, 189, 248, 0.05) 0px, transparent 50%),
    radial-gradient(at 100% 100%, rgba(45, 212, 191, 0.04) 0px, transparent 50%);
  background-attachment: fixed;
  transition: background-color var(--transition-slow), color var(--transition-slow);
  overflow-x: hidden;
}

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

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

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

/* ==========================================================================
   Navigation Bar
   ========================================================================== */

.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--bg-glass);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.navbar .container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  height: 70px;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
}

.brand-icon {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #ffffff;
  font-size: 1.1rem;
  box-shadow: var(--shadow-sm);
}

.nav-brand .title {
  display: flex;
  flex-direction: column;
}

.nav-brand .name {
  font-size: 1rem;
  line-height: 1.2;
}

.nav-brand .tagline {
  font-size: 0.75rem;
  color: var(--accent-primary);
  font-weight: 500;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  color: var(--text-secondary);
  font-weight: 500;
  font-size: 0.95rem;
  padding: 0.5rem 0;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link:hover,
.nav-link.active {
  color: var(--text-primary);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: var(--accent-gradient);
  border-radius: 2px;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.theme-toggle {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-normal);
  font-size: 1rem;
}

.theme-toggle:hover {
  color: var(--accent-primary);
  border-color: var(--border-accent);
  transform: translateY(-1px);
}

.mobile-nav-toggle {
  display: none;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 1.4rem;
  cursor: pointer;
}

/* ==========================================================================
   Buttons & Badges
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  font-weight: 600;
  font-size: 0.9rem;
  cursor: pointer;
  transition: all var(--transition-normal);
  border: none;
  text-decoration: none;
}

.btn-primary {
  background: var(--accent-gradient);
  color: #ffffff;
  box-shadow: 0 4px 14px rgba(56, 189, 248, 0.3);
}

.btn-primary:hover {
  color: #ffffff;
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(56, 189, 248, 0.4);
}

.btn-secondary {
  background: var(--bg-card);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
}

.btn-secondary:hover {
  background: var(--bg-card-hover);
  border-color: var(--border-accent);
  color: var(--accent-primary);
  transform: translateY(-2px);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.8rem;
}

.status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  background: var(--badge-green-bg);
  color: var(--badge-green-text);
  border: 1px solid var(--badge-green-border);
  font-size: 0.8rem;
  font-weight: 600;
}

.status-badge .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: var(--badge-green-text);
  box-shadow: 0 0 8px var(--badge-green-text);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.2); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

/* ==========================================================================
   Hero / About Section
   ========================================================================== */

.hero-section {
  padding: 130px 0 60px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 320px 1fr;
  gap: 3rem;
  align-items: start;
}

.profile-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  text-align: center;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-lg);
  position: sticky;
  top: 90px;
}

.avatar-wrapper {
  position: relative;
  width: 140px;
  height: 140px;
  margin: 0 auto 1.5rem;
}

.avatar-img {
  width: 100%;
  height: 100%;
  border-radius: 50%;
  object-fit: cover;
  border: 3px solid transparent;
  background-image: var(--accent-gradient);
  background-origin: border-box;
  box-shadow: var(--shadow-glow);
}

.profile-card h1 {
  font-size: 1.45rem;
  font-weight: 700;
  margin-bottom: 0.25rem;
}

.profile-card .subtitle {
  color: var(--accent-primary);
  font-weight: 600;
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

.profile-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.4rem;
  margin-bottom: 1.5rem;
}

.tag {
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  color: var(--tag-text);
  padding: 0.25rem 0.6rem;
  border-radius: var(--radius-sm);
  font-size: 0.75rem;
  font-weight: 600;
}

.social-links {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-top: 1.25rem;
}

.social-btn {
  width: 38px;
  height: 38px;
  border-radius: var(--radius-md);
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.social-btn:hover {
  color: var(--accent-primary);
  border-color: var(--border-accent);
  transform: translateY(-2px);
}

/* Bio Content */
.hero-content .elevator-pitch {
  font-size: 1.12rem;
  line-height: 1.8;
  color: var(--text-primary);
  margin-bottom: 2rem;
  padding: 1.5rem;
  background: var(--bg-card);
  border-left: 4px solid var(--accent-primary);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.pillars-title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.pillars-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.25rem;
  margin-bottom: 2.5rem;
}

.pillar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  transition: all var(--transition-normal);
}

.pillar-card:hover {
  border-color: var(--border-accent);
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}

.pillar-icon {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: var(--tag-bg);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.2rem;
  margin-bottom: 0.85rem;
}

.pillar-card h3 {
  font-size: 0.98rem;
  font-weight: 700;
  margin-bottom: 0.4rem;
}

.pillar-card p {
  font-size: 0.85rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Metrics Bar */
.metrics-bar {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
  text-align: center;
}

.metric-item .number {
  font-size: 1.6rem;
  font-weight: 800;
  background: var(--accent-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.metric-item .label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ==========================================================================
   Section Headers
   ========================================================================== */

.section {
  padding: 70px 0;
}

.section-header {
  margin-bottom: 2.5rem;
  text-align: left;
}

.section-tag {
  display: inline-block;
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent-primary);
  margin-bottom: 0.4rem;
}

.section-title {
  font-size: 1.85rem;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.section-description {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-top: 0.4rem;
  max-width: 650px;
}

/* ==========================================================================
   Projects Section
   ========================================================================== */

.filter-bar {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 2rem;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  padding: 0.45rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover,
.filter-btn.active {
  background: var(--accent-gradient);
  color: #ffffff;
  border-color: transparent;
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
  gap: 1.75rem;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-normal);
  backdrop-filter: blur(8px);
}

.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-accent);
  box-shadow: var(--shadow-lg);
}

.project-header-visual {
  height: 160px;
  background-size: cover;
  background-position: center;
  position: relative;
}

.project-header-visual::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 15, 25, 0.2) 0%, var(--bg-secondary) 100%);
}

.project-badge-overlay {
  position: absolute;
  top: 1rem;
  left: 1rem;
  z-index: 1;
}

.project-body {
  padding: 1.5rem;
  flex-grow: 1;
  display: flex;
  flex-direction: column;
}

.project-body h3 {
  font-size: 1.2rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.project-body p {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.project-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-bottom: 1.25rem;
}

.project-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

/* ==========================================================================
   Curriculum Vitae (CV) Section
   ========================================================================== */

.cv-container {
  display: grid;
  grid-template-columns: 2fr 1.2fr;
  gap: 2.5rem;
}

.timeline {
  position: relative;
  padding-left: 2rem;
  margin-bottom: 2.5rem;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border-color);
}

.timeline-item {
  position: relative;
  margin-bottom: 2rem;
}

.timeline-item:last-child {
  margin-bottom: 0;
}

.timeline-dot {
  position: absolute;
  left: -2rem;
  top: 5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-primary);
  border: 3px solid var(--accent-primary);
  box-shadow: 0 0 10px var(--accent-glow);
}

.timeline-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 0.35rem;
}

.timeline-title {
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--text-primary);
}

.timeline-meta {
  color: var(--accent-primary);
  font-weight: 600;
  font-size: 0.88rem;
  margin-bottom: 0.5rem;
}

.timeline-date {
  font-size: 0.8rem;
  color: var(--text-muted);
  font-weight: 600;
  font-family: var(--font-mono);
  background: var(--bg-card);
  padding: 0.15rem 0.5rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
}

.timeline-bullets {
  list-style: none;
  margin-top: 0.5rem;
}

.timeline-bullets li {
  position: relative;
  padding-left: 1.2rem;
  font-size: 0.88rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 0.35rem;
}

.timeline-bullets li::before {
  content: '▸';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
}

/* Skills & Cards on Right Column */
.cv-sidebar {
  display: flex;
  flex-direction: column;
  gap: 1.75rem;
}

.sidebar-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 1.5rem;
}

.sidebar-card h3 {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 1rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.skill-category {
  margin-bottom: 1.25rem;
}

.skill-category:last-child {
  margin-bottom: 0;
}

.skill-category h4 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 0.6rem;
}

.skill-tags-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}

/* ==========================================================================
   Contact Section & Footer
   ========================================================================== */

.contact-card {
  background: var(--bg-card);
  border: 1px solid var(--border-accent);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem;
  text-align: center;
  box-shadow: var(--shadow-glow);
}

.contact-card h2 {
  font-size: 1.75rem;
  font-weight: 800;
  margin-bottom: 0.75rem;
}

.contact-card p {
  color: var(--text-secondary);
  max-width: 600px;
  margin: 0 auto 2rem;
}

.contact-actions {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

.footer {
  border-top: 1px solid var(--border-color);
  padding: 2.5rem 0;
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  margin-top: 4rem;
}

/* ==========================================================================
   Interactive Project Modal
   ========================================================================== */

.modal-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(6px);
  z-index: 2000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.modal-backdrop.open {
  opacity: 1;
  pointer-events: auto;
}

.modal-content {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  max-width: 700px;
  width: 100%;
  max-height: 85vh;
  overflow-y: auto;
  padding: 2rem;
  position: relative;
  transform: translateY(20px) scale(0.98);
  transition: transform var(--transition-normal);
  box-shadow: var(--shadow-lg);
}

.modal-backdrop.open .modal-content {
  transform: translateY(0) scale(1);
}

.modal-close {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-secondary);
  width: 34px;
  height: 34px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1rem;
  transition: all var(--transition-fast);
}

.modal-close:hover {
  color: var(--text-primary);
  border-color: var(--border-accent);
}

.modal-header {
  margin-bottom: 1.5rem;
  padding-right: 2rem;
}

.modal-section {
  margin-bottom: 1.5rem;
}

.modal-section h4 {
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 0.4rem;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.modal-section p, 
.modal-section ul {
  font-size: 0.9rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.modal-section ul {
  padding-left: 1.2rem;
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */

@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }
  
  .profile-card {
    position: static;
  }
  
  .cv-container {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  
  .mobile-nav-toggle {
    display: block;
  }
  
  .nav-links.mobile-open {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 70px;
    left: 0;
    right: 0;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 1.5rem;
    gap: 1rem;
  }
  
  .metrics-bar {
    grid-template-columns: 1fr;
    gap: 1rem;
  }
}