/* ==========================================================================
   SELECT Project Hub - Dual Theme (Dark / Light) Stylesheet
   ========================================================================== */

/* Design Tokens - Light Mode (Default) */
:root,
[data-theme="light"] {
  --color-bg-deep: #f8fafc;
  --color-bg-canvas: #f1f5f9;
  --color-card-bg: rgba(255, 255, 255, 0.88);
  --color-card-bg-hover: #ffffff;

  --color-border-subtle: rgba(15, 23, 42, 0.08);
  --color-border-hover-blue: rgba(37, 99, 235, 0.45);
  --color-border-hover-teal: rgba(13, 148, 136, 0.45);
  --color-border-hover-purple: rgba(124, 58, 237, 0.45);
  --color-border-hover-amber: rgba(217, 119, 6, 0.45);

  --color-text-primary: #0f172a;
  --color-text-secondary: #475569;
  --color-text-muted: #64748b;

  --color-accent-blue: #2563eb;
  --color-accent-blue-light: #1d4ed8;
  --color-accent-blue-glow: rgba(37, 99, 235, 0.18);
  --color-accent-blue-surface: rgba(37, 99, 235, 0.08);

  --color-accent-teal: #0d9488;
  --color-accent-teal-light: #0f766e;
  --color-accent-teal-glow: rgba(13, 148, 136, 0.18);
  --color-accent-teal-surface: rgba(13, 148, 136, 0.08);

  --color-accent-purple: #7c3aed;
  --color-accent-purple-light: #6d28d9;
  --color-accent-purple-glow: rgba(124, 58, 237, 0.18);
  --color-accent-purple-surface: rgba(124, 58, 237, 0.08);

  --color-accent-amber: #d97706;
  --color-accent-amber-light: #b45309;
  --color-accent-amber-glow: rgba(217, 119, 6, 0.18);
  --color-accent-amber-surface: rgba(217, 119, 6, 0.08);

  --color-glow-blue: rgba(59, 130, 246, 0.25);
  --color-glow-teal: rgba(20, 184, 166, 0.22);
  --color-glow-purple: rgba(147, 51, 234, 0.22);
  --color-glow-amber: rgba(245, 158, 11, 0.2);
  --glow-opacity: 0.28;
  --grid-line-color: rgba(15, 23, 42, 0.035);

  --hero-title-gradient: linear-gradient(180deg, #0f172a 0%, #334155 100%);
  --tag-bg: rgba(15, 23, 42, 0.04);
  --tag-border: rgba(15, 23, 42, 0.08);
  --badge-bg: rgba(15, 23, 42, 0.04);
  --btn-bg: rgba(15, 23, 42, 0.04);
  --btn-bg-hover: rgba(15, 23, 42, 0.08);
  --btn-border-hover: rgba(15, 23, 42, 0.18);
  --logo-center-fill: #f8fafc;

  --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
  --card-shadow-hover-blue: 0 18px 36px -8px rgba(37, 99, 235, 0.18), 0 4px 12px -2px rgba(15, 23, 42, 0.04);
  --card-shadow-hover-teal: 0 18px 36px -8px rgba(13, 148, 136, 0.18), 0 4px 12px -2px rgba(15, 23, 42, 0.04);
  --card-shadow-hover-purple: 0 18px 36px -8px rgba(124, 58, 237, 0.18), 0 4px 12px -2px rgba(15, 23, 42, 0.04);
  --card-shadow-hover-amber: 0 18px 36px -8px rgba(217, 119, 6, 0.18), 0 4px 12px -2px rgba(15, 23, 42, 0.04);

  --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: 'Space Grotesk', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --transition-smooth: 240ms cubic-bezier(0.16, 1, 0.3, 1);
  --transition-bounce: 350ms cubic-bezier(0.34, 1.56, 0.64, 1);
  --container-max-width: 1320px;
}

/* Dark Mode Overrides */
[data-theme="dark"] {
  --color-bg-deep: #070b14;
  --color-bg-canvas: #0a0f1d;
  --color-card-bg: rgba(14, 21, 38, 0.72);
  --color-card-bg-hover: rgba(18, 27, 49, 0.88);
  
  --color-border-subtle: rgba(255, 255, 255, 0.08);
  --color-border-hover-blue: rgba(59, 130, 246, 0.55);
  --color-border-hover-teal: rgba(20, 184, 166, 0.55);
  --color-border-hover-purple: rgba(168, 85, 247, 0.55);
  --color-border-hover-amber: rgba(245, 158, 11, 0.55);

  --color-text-primary: #f8fafc;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;

  --color-accent-blue: #3b82f6;
  --color-accent-blue-light: #60a5fa;
  --color-accent-blue-glow: rgba(59, 130, 246, 0.22);
  --color-accent-blue-surface: rgba(59, 130, 246, 0.12);

  --color-accent-teal: #14b8a6;
  --color-accent-teal-light: #2dd4bf;
  --color-accent-teal-glow: rgba(20, 184, 166, 0.22);
  --color-accent-teal-surface: rgba(20, 184, 166, 0.12);

  --color-accent-purple: #a855f7;
  --color-accent-purple-light: #c084fc;
  --color-accent-purple-glow: rgba(168, 85, 247, 0.22);
  --color-accent-purple-surface: rgba(168, 85, 247, 0.12);

  --color-accent-amber: #f59e0b;
  --color-accent-amber-light: #fbbf24;
  --color-accent-amber-glow: rgba(245, 158, 11, 0.22);
  --color-accent-amber-surface: rgba(245, 158, 11, 0.12);

  --color-glow-blue: rgba(59, 130, 246, 0.5);
  --color-glow-teal: rgba(20, 184, 166, 0.4);
  --color-glow-purple: rgba(168, 85, 247, 0.4);
  --color-glow-amber: rgba(245, 158, 11, 0.35);
  --glow-opacity: 0.45;
  --grid-line-color: rgba(255, 255, 255, 0.02);

  --hero-title-gradient: linear-gradient(180deg, #ffffff 0%, #cbd5e1 100%);
  --tag-bg: rgba(255, 255, 255, 0.03);
  --tag-border: rgba(255, 255, 255, 0.06);
  --badge-bg: rgba(255, 255, 255, 0.04);
  --btn-bg: rgba(255, 255, 255, 0.04);
  --btn-bg-hover: rgba(255, 255, 255, 0.08);
  --btn-border-hover: rgba(255, 255, 255, 0.18);
  --logo-center-fill: #070b14;

  --card-shadow: none;
  --card-shadow-hover-blue: 0 16px 36px -10px var(--color-accent-blue-glow);
  --card-shadow-hover-teal: 0 16px 36px -10px var(--color-accent-teal-glow);
  --card-shadow-hover-purple: 0 16px 36px -10px var(--color-accent-purple-glow);
  --card-shadow-hover-amber: 0 16px 36px -10px var(--color-accent-amber-glow);
}

/* Base & Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  min-height: 100%;
}

body {
  background-color: var(--color-bg-deep);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  position: relative;
  display: flex;
  flex-direction: column;
  transition: background-color var(--transition-smooth), color var(--transition-smooth);
}

/* Ambient Lighting & Background Canvas */
.ambient-glow {
  position: fixed;
  border-radius: 50%;
  filter: blur(120px);
  pointer-events: none;
  z-index: 0;
  opacity: var(--glow-opacity);
  transition: opacity var(--transition-smooth);
}

.glow-blue {
  width: 520px;
  height: 520px;
  top: -120px;
  left: 10%;
  background: radial-gradient(circle, var(--color-glow-blue) 0%, rgba(37, 99, 235, 0.05) 70%, transparent 100%);
}

.glow-teal {
  width: 540px;
  height: 540px;
  bottom: -100px;
  right: 10%;
  background: radial-gradient(circle, var(--color-glow-teal) 0%, rgba(13, 148, 136, 0.05) 70%, transparent 100%);
}

.glow-purple {
  width: 500px;
  height: 500px;
  top: 45%;
  left: 50%;
  transform: translate(-50%, -50%);
  background: radial-gradient(circle, var(--color-glow-purple) 0%, rgba(124, 58, 237, 0.04) 70%, transparent 100%);
}

.glow-amber {
  width: 480px;
  height: 480px;
  top: 15%;
  right: 18%;
  background: radial-gradient(circle, var(--color-glow-amber) 0%, rgba(245, 158, 11, 0.04) 70%, transparent 100%);
}

.bg-grid-overlay {
  position: fixed;
  inset: 0;
  background-image: 
    linear-gradient(to right, var(--grid-line-color) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid-line-color) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 50%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 40%, #000 50%, transparent 100%);
  pointer-events: none;
  z-index: 1;
}

/* Layout Wrapper */
.page-wrapper {
  position: relative;
  z-index: 2;
  width: 100%;
  max-width: var(--container-max-width);
  min-height: 100vh;
  margin: 0 auto;
  padding: 2.25rem 2rem 2.5rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

/* Site Header */
.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: 2.5rem;
  width: 100%;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  user-select: none;
  text-decoration: none;
}

.brand-logo {
  height: 32px;
  width: auto;
  max-width: 32px;
  object-fit: contain;
  flex-shrink: 0;
  display: block;
  filter: drop-shadow(0 2px 10px rgba(59, 130, 246, 0.3));
  transition: transform var(--transition-bounce), filter var(--transition-smooth);
}

.brand:hover .brand-logo {
  transform: scale(1.08) rotate(1deg);
  filter: drop-shadow(0 4px 14px rgba(245, 158, 11, 0.4));
}

.brand-name {
  font-family: var(--font-mono);
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--color-text-primary);
  text-transform: uppercase;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.hub-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.38rem 0.85rem;
  border-radius: var(--radius-full);
  background: var(--badge-bg);
  border: 1px solid var(--color-border-subtle);
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  user-select: none;
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth), color var(--transition-smooth);
}

.badge-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent-teal-light);
  box-shadow: 0 0 8px var(--color-accent-teal);
}

/* Theme Toggle Button */
.theme-toggle-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  background: var(--btn-bg);
  border: 1px solid var(--color-border-subtle);
  color: var(--color-text-secondary);
  cursor: pointer;
  outline: none;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  transition: background-color var(--transition-smooth), 
              border-color var(--transition-smooth), 
              color var(--transition-smooth),
              transform var(--transition-smooth);
}

.theme-toggle-btn:hover {
  background: var(--btn-bg-hover);
  border-color: var(--btn-border-hover);
  color: var(--color-text-primary);
  transform: scale(1.05);
}

.theme-toggle-btn:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 2px;
}

/* Toggle icon display based on current theme */
.theme-icon {
  transition: transform var(--transition-bounce), opacity var(--transition-smooth);
}

/* In light mode (default): Moon is visible, Sun is hidden */
:root .icon-sun,
[data-theme="light"] .icon-sun {
  display: none;
}
:root .icon-moon,
[data-theme="light"] .icon-moon {
  display: block;
}

/* In dark mode: Sun is visible, Moon is hidden */
[data-theme="dark"] .icon-sun {
  display: block;
}
[data-theme="dark"] .icon-moon {
  display: none;
}

/* Hero Section */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 2rem 0 3.5rem;
}

.hero-section {
  text-align: center;
  margin-bottom: 3.25rem;
}

.hero-title {
  font-size: clamp(2rem, 4.5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  margin-bottom: 0.875rem;
  background: var(--hero-title-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: background var(--transition-smooth);
}

.hero-subtitle {
  font-size: clamp(1rem, 2vw, 1.1875rem);
  color: var(--color-text-secondary);
  font-weight: 400;
  letter-spacing: -0.01em;
  transition: color var(--transition-smooth);
}

/* Projects Grid */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
  width: 100%;
}

/* Project Card */
.project-card {
  position: relative;
  display: block;
  text-decoration: none;
  color: inherit;
  border-radius: var(--radius-lg);
  background: var(--color-card-bg);
  border: 1px solid var(--color-border-subtle);
  box-shadow: var(--card-shadow);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  overflow: hidden;
  transition: transform var(--transition-smooth), 
              border-color var(--transition-smooth), 
              background-color var(--transition-smooth),
              box-shadow var(--transition-smooth);
  cursor: pointer;
  outline: none;
}

.card-glow {
  position: absolute;
  inset: 0;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-smooth);
  z-index: 1;
}

.card-inner {
  position: relative;
  z-index: 2;
  padding: 2.25rem;
  display: flex;
  flex-direction: column;
  min-height: 290px;
  justify-content: space-between;
}

/* Card Header */
.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 2rem;
}

.icon-wrapper {
  width: 58px;
  height: 58px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform var(--transition-smooth), background-color var(--transition-smooth), border-color var(--transition-smooth);
}

.card-tag {
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.75rem;
  border-radius: var(--radius-full);
  background: var(--tag-bg);
  border: 1px solid var(--tag-border);
  color: var(--color-text-muted);
  transition: background-color var(--transition-smooth), border-color var(--transition-smooth), color var(--transition-smooth);
}

/* Blue Accent Card (Use Case Hub) */
.card-blue .icon-wrapper {
  background: var(--color-accent-blue-surface);
  color: var(--color-accent-blue-light);
  border: 1px solid rgba(59, 130, 246, 0.25);
}

.card-blue .card-glow {
  background: radial-gradient(circle at 20% 0%, var(--color-accent-blue-glow) 0%, transparent 60%);
}

.card-blue:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-hover-blue);
  background-color: var(--color-card-bg-hover);
  box-shadow: var(--card-shadow-hover-blue);
}

.card-blue:hover .card-glow {
  opacity: 1;
}

.card-blue:hover .icon-wrapper {
  transform: scale(1.04);
}

/* Teal Accent Card (Infrastructure Hub) */
.card-teal .icon-wrapper {
  background: var(--color-accent-teal-surface);
  color: var(--color-accent-teal-light);
  border: 1px solid rgba(20, 184, 166, 0.25);
}

.card-teal .card-glow {
  background: radial-gradient(circle at 20% 0%, var(--color-accent-teal-glow) 0%, transparent 60%);
}

.card-teal:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-hover-teal);
  background-color: var(--color-card-bg-hover);
  box-shadow: var(--card-shadow-hover-teal);
}

.card-teal:hover .card-glow {
  opacity: 1;
}

.card-teal:hover .icon-wrapper {
  transform: scale(1.04);
}

/* Purple Accent Card (Swift Plan) */
.card-purple .icon-wrapper {
  background: var(--color-accent-purple-surface);
  color: var(--color-accent-purple-light);
  border: 1px solid rgba(168, 85, 247, 0.25);
}

.card-purple .card-glow {
  background: radial-gradient(circle at 20% 0%, var(--color-accent-purple-glow) 0%, transparent 60%);
}

.card-purple:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-hover-purple);
  background-color: var(--color-card-bg-hover);
  box-shadow: var(--card-shadow-hover-purple);
}

.card-purple:hover .card-glow {
  opacity: 1;
}

.card-purple:hover .icon-wrapper {
  transform: scale(1.04);
}

/* Amber Accent Card (SSO Dashboard) */
.card-amber .icon-wrapper {
  background: var(--color-accent-amber-surface);
  color: var(--color-accent-amber-light);
  border: 1px solid rgba(245, 158, 11, 0.25);
}

.card-amber .card-glow {
  background: radial-gradient(circle at 20% 0%, var(--color-accent-amber-glow) 0%, transparent 60%);
}

.card-amber:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-hover-amber);
  background-color: var(--color-card-bg-hover);
  box-shadow: var(--card-shadow-hover-amber);
}

.card-amber:hover .card-glow {
  opacity: 1;
}

.card-amber:hover .icon-wrapper {
  transform: scale(1.04);
}

/* Card Body */
.card-body {
  margin-bottom: 2rem;
}

.card-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text-primary);
  margin-bottom: 0.625rem;
  transition: color var(--transition-smooth);
}

.card-description {
  font-size: 0.95rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  transition: color var(--transition-smooth);
}

/* Card Footer */
.card-footer {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--color-border-subtle);
  transition: border-color var(--transition-smooth);
}

.action-label {
  font-size: 0.9375rem;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--color-text-primary);
  transition: color var(--transition-smooth);
}

.action-arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: transform var(--transition-smooth), color var(--transition-smooth);
}

.card-blue:hover .action-label {
  color: var(--color-accent-blue);
}

.card-blue:hover .action-arrow {
  color: var(--color-accent-blue);
  transform: translateX(5px);
}

.card-teal:hover .action-label {
  color: var(--color-accent-teal);
}

.card-teal:hover .action-arrow {
  color: var(--color-accent-teal);
  transform: translateX(5px);
}

.card-purple:hover .action-label {
  color: var(--color-accent-purple);
}

.card-purple:hover .action-arrow {
  color: var(--color-accent-purple);
  transform: translateX(5px);
}

.card-amber:hover .action-label {
  color: var(--color-accent-amber);
}

.card-amber:hover .action-arrow {
  color: var(--color-accent-amber);
  transform: translateX(5px);
}

/* Accessible Focus States */
.project-card:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 3px;
  border-color: var(--color-accent-blue);
  transform: translateY(-2px);
}

.card-teal:focus-visible {
  outline-color: var(--color-accent-teal);
  border-color: var(--color-accent-teal);
}

.card-purple:focus-visible {
  outline-color: var(--color-accent-purple);
  border-color: var(--color-accent-purple);
}

.card-amber:focus-visible {
  outline-color: var(--color-accent-amber);
  border-color: var(--color-accent-amber);
}

/* Site Footer */
.site-footer {
  text-align: center;
  padding-top: 2rem;
  border-top: 1px solid var(--color-border-subtle);
  transition: border-color var(--transition-smooth);
}

.footer-text {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--color-text-muted);
  text-transform: uppercase;
  transition: color var(--transition-smooth);
}

/* Responsive Styles */
@media (max-width: 1140px) {
  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
    max-width: 760px;
    margin: 0 auto;
    gap: 1.5rem;
  }
}

@media (max-width: 680px) {
  .page-wrapper {
    padding: 1.75rem 1.25rem 2rem;
  }

  .projects-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
    gap: 1.25rem;
  }

  .card-inner {
    padding: 1.75rem;
    min-height: auto;
  }

  .hero-section {
    margin-bottom: 2.25rem;
  }

  .hero-title {
    font-size: 2.125rem;
  }
}

@media (max-width: 480px) {
  .site-header {
    padding-bottom: 1.75rem;
  }

  .brand-name {
    font-size: 1rem;
  }

  .card-title {
    font-size: 1.3125rem;
  }

  .hero-title {
    font-size: 1.875rem;
  }
}

/* Respect Accessibility Preference for Reduced Motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .project-card:hover {
    transform: none !important;
  }

  .project-card:hover .action-arrow {
    transform: none !important;
  }

  .project-card:hover .icon-wrapper {
    transform: none !important;
  }
}