/* ==========================================================================
   PORTFOLIO DESIGN SYSTEM & STYLESHEET
   Clean, modern, responsive CSS with CSS variables, light/dark themes
   ========================================================================== */

:root {
  /* Color Palette - Light Theme */
  --bg-primary: #ffffff;
  --bg-secondary: #f8fafc;
  --bg-card: #ffffff;
  --bg-card-hover: #f1f5f9;
  --bg-nav: rgba(255, 255, 255, 0.85);
  --border-color: #e2e8f0;
  --border-focus: #3b82f6;

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

  --accent-primary: #2563eb;
  --accent-hover: #1d4ed8;
  --accent-light: #eff6ff;
  --accent-glow: rgba(37, 99, 235, 0.15);

  --badge-bg: #e0f2fe;
  --badge-text: #0369a1;
  --success: #10b981;
  --success-bg: #ecfdf5;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;

  /* Elevation & Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.08);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.06);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Layout */
  --container-max: 1200px;
  --header-height: 72px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;
}

[data-theme="dark"] {
  /* Color Palette - Dark Theme */
  --bg-primary: #0b0f19;
  --bg-secondary: #111827;
  --bg-card: #172033;
  --bg-card-hover: #1e293b;
  --bg-nav: rgba(11, 15, 25, 0.88);
  --border-color: #273549;
  --border-focus: #60a5fa;

  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-muted: #94a3b8;
  --text-light: #ffffff;

  --accent-primary: #3b82f6;
  --accent-hover: #60a5fa;
  --accent-light: rgba(59, 130, 246, 0.15);
  --accent-glow: rgba(59, 130, 246, 0.25);

  --badge-bg: #1e293b;
  --badge-text: #93c5fd;
  --success: #34d399;
  --success-bg: rgba(52, 211, 153, 0.15);

  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.5), 0 2px 4px -2px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.6), 0 4px 6px -4px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.7), 0 8px 10px -6px rgba(0, 0, 0, 0.6);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-family: var(--font-sans);
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--header-height) + 16px);
  -webkit-text-size-adjust: 100%;
}

body {
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  overflow-x: hidden;
}

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

a:hover, a:focus-visible {
  color: var(--accent-hover);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button, input, textarea {
  font-family: inherit;
  font-size: 1rem;
}

button {
  cursor: pointer;
  border: none;
  background: none;
}

/* Accessible Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--accent-primary);
  color: #fff;
  padding: 0.5rem 1rem;
  z-index: 1000;
  border-radius: var(--radius-sm);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 1rem;
}

/* Container */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: 1.25rem;
  padding-right: 1.25rem;
}

/* Section Header Typography */
.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

.section-tag {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-primary);
  background: var(--accent-light);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: 2.25rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--text-primary);
  letter-spacing: -0.02em;
  margin-bottom: 1rem;
}

.section-subtitle {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  max-width: 620px;
  margin-left: auto;
  margin-right: auto;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-weight: 600;
  font-size: 0.9375rem;
  padding: 0.75rem 1.4rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-normal);
  text-align: center;
}

.btn-primary {
  background-color: var(--accent-primary);
  color: var(--text-light);
  box-shadow: 0 4px 14px var(--accent-glow);
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  color: var(--text-light);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px var(--accent-glow);
}

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

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

.btn-sm {
  padding: 0.5rem 0.95rem;
  font-size: 0.875rem;
  border-radius: var(--radius-sm);
}

/* ==========================================================================
   HEADER & NAVBAR
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  left: 0;
  width: 100%;
  z-index: 100;
  background-color: var(--bg-nav);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.navbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-weight: 800;
  font-size: 1.25rem;
  color: var(--text-primary);
  letter-spacing: -0.02em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--accent-primary), #8b5cf6);
  color: #ffffff;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 800;
  font-size: 1rem;
}

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

.nav-link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
  padding: 0.25rem 0;
  transition: color var(--transition-fast);
}

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

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--accent-primary);
  border-radius: var(--radius-full);
}

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

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

.theme-toggle-btn:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background-color: var(--bg-card-hover);
}

.mobile-menu-btn {
  display: none;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 5px;
  color: var(--text-primary);
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  transition: all var(--transition-normal);
}

.hamburger-line {
  width: 20px;
  height: 2px;
  background-color: currentColor;
  transition: all var(--transition-normal);
}

.mobile-menu-btn[aria-expanded="true"] .hamburger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.mobile-menu-btn[aria-expanded="true"] .hamburger-line:nth-child(2) {
  opacity: 0;
}
.mobile-menu-btn[aria-expanded="true"] .hamburger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */
.hero {
  padding-top: 5rem;
  padding-bottom: 5rem;
  position: relative;
  overflow: hidden;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  align-items: center;
  gap: 3.5rem;
}

.hero-badge-wrapper {
  margin-bottom: 1.25rem;
}

.hero-status-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  background-color: var(--success-bg);
  color: var(--success);
  border: 1px solid rgba(16, 185, 129, 0.25);
  font-size: 0.8125rem;
  font-weight: 600;
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
}

.pulse-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: currentColor;
  position: relative;
}

.pulse-dot::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  background-color: currentColor;
  animation: pulse-ring 1.8s cubic-bezier(0.24, 0, 0.38, 1) infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(1); opacity: 0.8; }
  100% { transform: scale(2.8); opacity: 0; }
}

.hero-greeting {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--accent-primary);
  margin-bottom: 0.5rem;
}

.hero-title {
  font-size: 3.25rem;
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 1.25rem;
}

.hero-title .highlight {
  background: linear-gradient(135deg, var(--accent-primary) 20%, #8b5cf6 80%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-pitch {
  font-size: 1.1875rem;
  color: var(--text-secondary);
  line-height: 1.65;
  margin-bottom: 2rem;
  max-width: 540px;
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  align-items: center;
  margin-bottom: 2rem;
}

.hero-socials {
  display: flex;
  align-items: center;
  gap: 1rem;
}

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

.hero-social-link:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  background-color: var(--accent-light);
  transform: translateY(-2px);
}

.hero-visual {
  display: flex;
  justify-content: center;
  position: relative;
}

.hero-card {
  position: relative;
  width: 100%;
  max-width: 380px;
  background: linear-gradient(145deg, var(--bg-card), var(--bg-secondary));
  padding: 1.25rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-xl);
}

.hero-avatar-wrapper {
  position: relative;
  border-radius: var(--radius-md);
  overflow: hidden;
  aspect-ratio: 1 / 1;
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
}

.hero-avatar-wrapper img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.floating-pill {
  position: absolute;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  padding: 0.65rem 1rem;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  gap: 0.6rem;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--text-primary);
}

.pill-left {
  bottom: -15px;
  left: -20px;
}

.pill-right {
  top: -15px;
  right: -20px;
}

.pill-icon {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: 0.75rem;
}

.pill-blue { background-color: #3b82f6; }
.pill-purple { background-color: #8b5cf6; }

/* ==========================================================================
   ABOUT SECTION
   ========================================================================== */
.about {
  padding-top: 5rem;
  padding-bottom: 5rem;
  background-color: var(--bg-secondary);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  align-items: center;
}

.about-bio {
  color: var(--text-secondary);
  font-size: 1.0625rem;
  line-height: 1.7;
}

.about-bio p {
  margin-bottom: 1.25rem;
}

.about-bio strong {
  color: var(--text-primary);
}

.about-stats-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.25rem;
}

.stat-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.5rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-normal), border-color var(--transition-normal);
}

.stat-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-primary);
}

.stat-number {
  font-size: 2.25rem;
  font-weight: 800;
  color: var(--accent-primary);
  line-height: 1;
  margin-bottom: 0.5rem;
}

.stat-label {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.stat-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ==========================================================================
   SKILLS SECTION
   ========================================================================== */
.skills {
  padding-top: 5rem;
  padding-bottom: 5rem;
}

.skills-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.skill-category-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-md);
  transition: all var(--transition-normal);
}

.skill-category-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lg);
}

.skill-category-header {
  display: flex;
  align-items: center;
  gap: 0.85rem;
  margin-bottom: 1.5rem;
}

.category-icon {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-md);
  background-color: var(--accent-light);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
}

.category-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.skills-list {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  list-style: none;
}

.skill-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.85rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 500;
  transition: all var(--transition-fast);
}

.skill-pill:hover {
  background-color: var(--accent-light);
  color: var(--accent-primary);
  border-color: var(--accent-primary);
  transform: scale(1.03);
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */
.projects {
  padding-top: 5rem;
  padding-bottom: 5rem;
  background-color: var(--bg-secondary);
}

.projects-filter-bar {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  margin-bottom: 2.5rem;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 0.5rem 1.25rem;
  border-radius: var(--radius-full);
  font-size: 0.875rem;
  font-weight: 600;
  background-color: var(--bg-card);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.filter-btn:hover {
  color: var(--accent-primary);
  border-color: var(--accent-primary);
}

.filter-btn.active {
  background-color: var(--accent-primary);
  color: #ffffff;
  border-color: var(--accent-primary);
  box-shadow: 0 2px 8px var(--accent-glow);
}

.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 2rem;
}

.project-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal);
}

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

.project-thumb {
  position: relative;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background-color: var(--bg-secondary);
}

.project-thumb img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.project-card:hover .project-thumb img {
  transform: scale(1.05);
}

.project-category-badge {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background-color: rgba(15, 23, 42, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  color: #ffffff;
  font-size: 0.75rem;
  font-weight: 600;
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
}

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

.project-title {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.project-description {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.55;
  margin-bottom: 1.25rem;
  flex-grow: 1;
}

.project-tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
  margin-bottom: 1.5rem;
}

.tech-tag {
  font-size: 0.75rem;
  font-weight: 600;
  background-color: var(--badge-bg);
  color: var(--badge-text);
  padding: 0.25rem 0.55rem;
  border-radius: var(--radius-sm);
}

.project-links {
  display: flex;
  gap: 0.75rem;
  margin-top: auto;
  padding-top: 1rem;
  border-top: 1px solid var(--border-color);
}

.project-links .btn {
  flex: 1;
}

/* ==========================================================================
   CONTACT SECTION
   ========================================================================== */
.contact {
  padding-top: 5rem;
  padding-bottom: 5rem;
}

.contact-grid {
  display: grid;
  grid-template-columns: 0.9fr 1.1fr;
  gap: 3.5rem;
}

.contact-info {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.contact-item-card {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 1.25rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
}

.contact-icon-box {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background-color: var(--accent-light);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-item-label {
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 0.25rem;
}

.contact-item-value {
  font-size: 1rem;
  font-weight: 600;
  color: var(--text-primary);
  word-break: break-all;
}

.contact-socials-group {
  margin-top: 0.5rem;
}

.contact-social-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.75rem;
}

.social-button {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.55rem 1rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

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

/* Contact Form */
.contact-form-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem;
  box-shadow: var(--shadow-md);
}

.form-title {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
}

.form-subtitle {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  margin-bottom: 1.5rem;
}

.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 0.45rem;
}

.form-control {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: 0.9375rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background-color: var(--bg-secondary);
  color: var(--text-primary);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-control:focus {
  outline: none;
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px var(--accent-glow);
}

textarea.form-control {
  resize: vertical;
  min-height: 120px;
}

.form-error {
  display: none;
  color: #ef4444;
  font-size: 0.75rem;
  font-weight: 500;
  margin-top: 0.35rem;
}

.form-group.has-error .form-control {
  border-color: #ef4444;
}

.form-group.has-error .form-error {
  display: block;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: 2rem;
  right: 2rem;
  z-index: 1000;
}

.toast {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  padding: 1rem 1.4rem;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-xl);
  transform: translateY(100px);
  opacity: 0;
  transition: all var(--transition-normal);
  pointer-events: none;
}

.toast.show {
  transform: translateY(0);
  opacity: 1;
  pointer-events: auto;
}

.toast.toast-success {
  border-left: 4px solid var(--success);
}

.toast-icon {
  color: var(--success);
}

/* ==========================================================================
   INTERACTIVE MODAL (Project Preview Demo & CV)
   ========================================================================== */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.modal-backdrop.active {
  display: flex;
  opacity: 1;
}

.modal-dialog {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  width: 100%;
  max-width: 640px;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-xl);
  transform: scale(0.95);
  transition: transform var(--transition-normal);
  padding: 2rem;
  position: relative;
}

.modal-backdrop.active .modal-dialog {
  transform: scale(1);
}

.modal-close-btn {
  position: absolute;
  top: 1.25rem;
  right: 1.25rem;
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--bg-secondary);
  color: var(--text-secondary);
  border: 1px solid var(--border-color);
  transition: all var(--transition-fast);
}

.modal-close-btn:hover {
  background-color: var(--bg-card-hover);
  color: var(--text-primary);
}

.modal-header {
  margin-bottom: 1.25rem;
}

.modal-title {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  margin-bottom: 0.25rem;
}

.modal-body {
  color: var(--text-secondary);
  font-size: 0.95rem;
  line-height: 1.6;
}

.modal-demo-box {
  background-color: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.25rem 0;
}

/* ==========================================================================
   FOOTER
   ========================================================================== */
.site-footer {
  background-color: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding-top: 3.5rem;
  padding-bottom: 3.5rem;
  color: var(--text-secondary);
  font-size: 0.9375rem;
}

.footer-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2rem;
  flex-wrap: wrap;
  gap: 1.5rem;
}

.footer-brand {
  font-weight: 700;
  font-size: 1.15rem;
  color: var(--text-primary);
}

.footer-nav {
  display: flex;
  gap: 1.75rem;
  list-style: none;
}

.footer-nav a {
  color: var(--text-secondary);
  transition: color var(--transition-fast);
}

.footer-nav a:hover {
  color: var(--accent-primary);
}

.footer-bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 1.75rem;
  border-top: 1px solid var(--border-color);
  flex-wrap: wrap;
  gap: 1rem;
}

.back-to-top-btn {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--text-secondary);
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 0.45rem 0.95rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

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

/* ==========================================================================
   RESPONSIVENESS (Mobile 375px, Tablet 768px, Desktop 1280px+)
   ========================================================================== */

/* Tablet (max-width: 1024px) */
@media (max-width: 1024px) {
  .hero-grid {
    grid-template-columns: 1fr;
    text-align: center;
    gap: 3rem;
  }

  .hero-pitch {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-cta {
    justify-content: center;
  }

  .hero-socials {
    justify-content: center;
  }

  .skills-container {
    grid-template-columns: repeat(2, 1fr);
  }

  .projects-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
}

/* Tablet & Mobile (max-width: 768px) */
@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  .section-title {
    font-size: 1.85rem;
  }

  .hero-title {
    font-size: 2.35rem;
  }

  .mobile-menu-btn {
    display: flex;
  }

  .nav-menu {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: 100%;
    background-color: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-xl);
    flex-direction: column;
    padding: 1.5rem;
    gap: 1.25rem;
    transform: translateY(-150%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
  }

  .nav-menu.active {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }

  .about-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .skills-container {
    grid-template-columns: 1fr;
  }

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

  .floating-pill {
    display: none;
  }
}

/* Small Mobile (375px) */
@media (max-width: 480px) {
  .hero-title {
    font-size: 2rem;
  }

  .hero-cta .btn {
    width: 100%;
  }

  .about-stats-grid {
    grid-template-columns: 1fr;
  }

  .contact-form-card {
    padding: 1.5rem;
  }

  .footer-top {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-nav {
    flex-direction: column;
    gap: 0.75rem;
  }

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }
}