/* ==========================================================================
   AKHIL SHIBU · DATA ANALYTICS & BI PORTFOLIO
   Design System: Professional Light-Mode Executive Data Architecture
   ========================================================================== */

:root {
  --bg-base: #f8fafc;
  --bg-surface: #ffffff;
  --bg-surface-elevated: #f1f5f9;
  --bg-surface-subtle: #f8fafc;
  --bg-overlay: rgba(255, 255, 255, 0.94);

  --border-subtle: #e2e8f0;
  --border-medium: #cbd5e1;
  --border-primary: rgba(2, 132, 199, 0.35);
  --border-emerald: rgba(5, 150, 105, 0.35);

  --text-main: #0f172a;
  --text-body: #334155;
  --text-muted: #64748b;
  --text-dim: #94a3b8;
  --text-white: #ffffff;

  --accent-primary: #0284c7;       /* Sky 600 */
  --accent-primary-hover: #0369a1; /* Sky 700 */
  --accent-primary-light: #e0f2fe; /* Sky 100 */

  --accent-emerald: #059669;       /* Emerald 600 */
  --accent-emerald-light: #ecfdf5; /* Emerald 50 */

  --accent-indigo: #4f46e5;        /* Indigo 600 */
  --accent-indigo-light: #eef2ff;  /* Indigo 50 */

  --accent-amber: #d97706;

  --font-sans: 'Plus Jakarta Sans', system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', ui-monospace, Menlo, Consolas, monospace;

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-full: 9999px;

  --shadow-sm: 0 1px 3px rgba(15, 23, 42, 0.05);
  --shadow-card: 0 4px 18px -2px rgba(15, 23, 42, 0.06);
  --shadow-hover: 0 12px 32px -4px rgba(15, 23, 42, 0.1);
  --shadow-glow: 0 0 20px -2px rgba(2, 132, 199, 0.25);

  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  color-scheme: light;
  max-width: 100vw;
  overflow-x: hidden;
}

body {
  font-family: var(--font-sans);
  background-color: var(--bg-base);
  color: var(--text-body);
  line-height: 1.65;
  font-size: 16px;
  max-width: 100vw;
  overflow-x: hidden;
  background-image: 
    linear-gradient(rgba(148, 163, 184, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(148, 163, 184, 0.08) 1px, transparent 1px);
  background-size: 36px 36px;
  background-attachment: fixed;
}

/* Ensure grid items don't force track expansion */
.hero-grid > *,
.projects-grid > *,
.skills-grid > *,
.workflow-chain > *,
.experience-grid > *,
.courses-grid > * {
  min-width: 0;
  max-width: 100%;
}

/* Typography Defaults */
h1, h2, h3, h4 {
  color: var(--text-main);
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

p {
  color: var(--text-body);
  font-size: 0.975rem;
  line-height: 1.65;
}

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

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

/* Focus Accessibility */
:focus-visible {
  outline: 2px solid var(--accent-primary);
  outline-offset: 3px;
  border-radius: var(--radius-sm);
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  background: var(--text-main);
  color: #ffffff;
  font-weight: 700;
  padding: 0.75rem 1.25rem;
  border-radius: var(--radius-sm);
  z-index: 9999;
  transition: top var(--transition-fast);
}

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

.container {
  width: min(1180px, 100% - 2rem);
  margin-inline: auto;
}

section {
  padding: 4.25rem 0;
  position: relative;
}

/* Section Headers */
.section-header {
  margin-bottom: 2.25rem;
}

.section-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent-primary);
  background: var(--accent-primary-light);
  border: 1px solid var(--border-primary);
  padding: 0.25rem 0.65rem;
  border-radius: var(--radius-full);
  margin-bottom: 0.75rem;
}

.section-tag::before {
  content: "";
  display: inline-block;
  width: 6px;
  height: 6px;
  background: var(--accent-primary);
  border-radius: 50%;
}

.section-title {
  font-size: clamp(1.75rem, 3.5vw, 2.35rem);
  margin-bottom: 0.5rem;
  color: var(--text-main);
}

.section-desc {
  max-width: 680px;
  color: var(--text-muted);
  font-size: 1.025rem;
}

/* ==========================================================================
   Navigation Bar (Light Frosted Glass)
   ========================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-overlay);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-subtle);
  transition: border-color var(--transition-normal);
}

.site-nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
  position: relative;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  text-decoration: none;
  flex-shrink: 1;
  min-width: 0;
}

.brand-badge {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  background: var(--accent-primary-light);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-sm);
  color: var(--accent-primary);
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 0.85rem;
}

.brand-text {
  font-weight: 700;
  font-size: 1.05rem;
  color: var(--text-main);
  letter-spacing: -0.01em;
}

.brand-sub {
  color: var(--text-muted);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  padding-left: 0.4rem;
  border-left: 1px solid var(--border-medium);
  margin-left: 0.4rem;
}

.nav-menu {
  display: flex;
  align-items: center;
  list-style: none;
  gap: 0.35rem;
}

.nav-link {
  color: var(--text-body);
  font-size: 0.85rem;
  font-weight: 500;
  padding: 0.4rem 0.65rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-link:hover {
  color: var(--text-main);
  background: var(--bg-surface-elevated);
}

.nav-link.active {
  color: var(--accent-primary);
  background: var(--accent-primary-light);
  font-weight: 600;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  background: var(--accent-primary);
  color: #ffffff !important;
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 600;
  padding: 0.4rem 0.85rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.nav-cta:hover {
  background: var(--accent-primary-hover);
  transform: translateY(-1px);
}

.nav-toggle {
  display: none;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  border-radius: var(--radius-sm);
  padding: 0.5rem;
  cursor: pointer;
  color: var(--text-main);
  flex-shrink: 0;
}

.nav-toggle svg {
  display: block;
  width: 22px;
  height: 22px;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding-top: 3.5rem;
  padding-bottom: 4rem;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 2.75rem;
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
  gap: 1.15rem;
  min-width: 0;
}

.hero-status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  padding: 0.35rem 0.85rem;
  border-radius: var(--radius-full);
  width: fit-content;
  font-size: 0.825rem;
  color: var(--text-body);
  box-shadow: var(--shadow-sm);
}

.pulse-indicator {
  position: relative;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent-emerald);
}

.pulse-indicator::after {
  content: "";
  position: absolute;
  inset: -3px;
  border-radius: 50%;
  border: 1px solid var(--accent-emerald);
  animation: pulse-ring 2s infinite ease-out;
}

@keyframes pulse-ring {
  0% { transform: scale(0.8); opacity: 1; }
  100% { transform: scale(2.2); opacity: 0; }
}

.hero-title {
  font-size: clamp(2.2rem, 4.6vw, 3.6rem);
  font-weight: 800;
  letter-spacing: -0.035em;
  line-height: 1.12;
  word-break: break-word;
  color: var(--text-main);
}

.hero-title .accent-text {
  color: var(--accent-primary);
  background: linear-gradient(135deg, #0284c7 0%, #4f46e5 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--accent-primary);
  line-height: 1.5;
}

.hero-description {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--text-body);
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 0.25rem;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  font-size: 0.885rem;
  font-weight: 600;
  padding: 0.65rem 1.25rem;
  border-radius: var(--radius-md);
  cursor: pointer;
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  text-decoration: none;
  min-height: 44px;
}

.btn-primary {
  background: var(--accent-primary);
  color: #ffffff;
}

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

.btn-secondary {
  background: var(--bg-surface);
  border-color: var(--border-medium);
  color: var(--text-main);
  box-shadow: var(--shadow-sm);
}

.btn-secondary:hover {
  background: var(--bg-surface-elevated);
  border-color: var(--accent-primary);
  transform: translateY(-1px);
}

.btn-ghost {
  background: transparent;
  border-color: var(--border-subtle);
  color: var(--text-muted);
}

.btn-ghost:hover {
  color: var(--text-main);
  background: var(--bg-surface);
  border-color: var(--border-medium);
}

.btn-sm {
  padding: 0.4rem 0.85rem;
  font-size: 0.8rem;
  min-height: 36px;
  font-family: var(--font-mono);
}

/* ==========================================================================
   Executive 3D Data Visualizer Card (Light Theme)
   ========================================================================== */
.v3d-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-top: 3px solid var(--accent-primary);
  border-radius: var(--radius-lg);
  padding: 1.25rem;
  box-shadow: var(--shadow-card);
  position: relative;
  min-width: 0;
  display: flex;
  flex-direction: column;
}

.v3d-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
  padding-bottom: 0.65rem;
  border-bottom: 1px solid var(--border-subtle);
  gap: 0.5rem;
  flex-wrap: wrap;
}

.v3d-badge {
  display: flex;
  align-items: center;
  gap: 0.45rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--accent-primary);
}

.v3d-modes {
  display: flex;
  gap: 0.25rem;
  background: var(--bg-surface-elevated);
  padding: 0.2rem;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-subtle);
}

.v3d-mode-btn {
  background: transparent;
  border: none;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  color: var(--text-muted);
  padding: 0.25rem 0.6rem;
  border-radius: 4px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.v3d-mode-btn:hover {
  color: var(--text-main);
}

.v3d-mode-btn.active {
  background: #ffffff;
  color: var(--accent-primary);
  box-shadow: 0 1px 3px rgba(15, 23, 42, 0.1);
}

.v3d-canvas-wrap {
  width: 100%;
  height: 290px;
  position: relative;
  background: linear-gradient(180deg, #f8fafc 0%, #ffffff 100%);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-subtle);
  overflow: hidden;
}

.v3d-canvas-container {
  width: 100%;
  height: 100%;
  cursor: grab;
}

.v3d-canvas-container:active {
  cursor: grabbing;
}

.v3d-tooltip {
  position: absolute;
  top: 1rem;
  left: 1rem;
  background: rgba(15, 23, 42, 0.92);
  color: #ffffff;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-sm);
  pointer-events: none;
  opacity: 0;
  transition: opacity 0.2s ease;
  box-shadow: var(--shadow-card);
  line-height: 1.4;
  z-index: 10;
}

.v3d-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.725rem;
  color: var(--text-muted);
}

/* ==========================================================================
   Featured Projects (Case Studies)
   ========================================================================== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.project-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  box-shadow: var(--shadow-card);
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
  position: relative;
  min-width: 0;
}

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

.project-card.flagship {
  border-top: 3px solid var(--accent-primary);
}

.project-badge-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.85rem;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.project-category {
  font-family: var(--font-mono);
  font-size: 0.725rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent-primary);
}

.project-status {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-full);
}

.status-completed {
  background: var(--accent-emerald-light);
  color: var(--accent-emerald);
  border: 1px solid var(--border-emerald);
  font-weight: 600;
}

.project-title {
  font-size: 1.35rem;
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.project-summary {
  color: var(--text-body);
  font-size: 0.925rem;
  line-height: 1.6;
  margin-bottom: 1.25rem;
}

.project-deepdive {
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 0.95rem;
  margin-bottom: 1.25rem;
  font-size: 0.85rem;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.deepdive-row {
  display: flex;
  gap: 0.5rem;
  line-height: 1.5;
}

.deepdive-label {
  font-family: var(--font-mono);
  font-size: 0.725rem;
  font-weight: 700;
  color: var(--text-muted);
  min-width: 80px;
  text-transform: uppercase;
}

.deepdive-text {
  color: var(--text-main);
}

.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 0.75rem;
  margin-bottom: 1.25rem;
}

.tech-pill {
  font-family: var(--font-mono);
  font-size: 0.725rem;
  color: var(--text-body);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  padding: 0.2rem 0.55rem;
  border-radius: var(--radius-sm);
}

.project-links {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

/* ==========================================================================
   Core Skills & Methodology Framework
   ========================================================================== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.skill-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.65rem;
  box-shadow: var(--shadow-card);
  min-width: 0;
}

.skill-card h3 {
  font-size: 1.15rem;
  margin-bottom: 0.85rem;
  color: var(--text-main);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.skill-card h3 svg {
  color: var(--accent-primary);
}

.skill-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.45rem;
}

.skill-tag {
  font-family: var(--font-mono);
  font-size: 0.775rem;
  color: var(--text-body);
  background: var(--bg-surface-elevated);
  border: 1px solid var(--border-subtle);
  padding: 0.3rem 0.65rem;
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.skill-tag:hover {
  border-color: var(--accent-primary);
  background: var(--accent-primary-light);
  color: var(--accent-primary);
}

/* Workflow Step Line */
.workflow-chain {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1rem;
}

.workflow-step {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
  min-width: 0;
}

.step-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-primary);
  margin-bottom: 0.35rem;
}

.step-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text-main);
  margin-bottom: 0.35rem;
}

.step-desc {
  font-size: 0.825rem;
  color: var(--text-body);
  line-height: 1.5;
}

/* ==========================================================================
   Experience & Education / Accredited Courses
   ========================================================================== */
.experience-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.5rem;
  margin-bottom: 2rem;
}

.experience-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg);
  padding: 1.75rem;
  box-shadow: var(--shadow-card);
  min-width: 0;
}

.exp-header {
  margin-bottom: 0.75rem;
}

.exp-role {
  font-size: 1.2rem;
  color: var(--text-main);
  margin-bottom: 0.25rem;
}

.exp-company {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--accent-primary);
  font-weight: 600;
}

.exp-desc {
  font-size: 0.9rem;
  margin-bottom: 1rem;
}

/* Accredited Courses Grid */
.courses-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
  margin-top: 1.25rem;
}

.course-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  box-shadow: var(--shadow-sm);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.course-provider-tag {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 700;
  color: var(--accent-primary);
  text-transform: uppercase;
  margin-bottom: 0.35rem;
}

.course-title {
  font-size: 1.05rem;
  color: var(--text-main);
  margin-bottom: 0.5rem;
}

.course-platform {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-muted);
}

/* ==========================================================================
   FAQ Accordions
   ========================================================================== */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-width: 820px;
}

.faq-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: border-color var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--border-medium);
}

.faq-trigger {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.15rem 1.35rem;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  text-align: left;
  cursor: pointer;
  gap: 0.75rem;
}

.faq-icon {
  font-size: 1.25rem;
  color: var(--accent-primary);
  transition: transform var(--transition-normal);
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(45deg);
}

.faq-content {
  padding: 0 1.35rem 1.15rem 1.35rem;
  display: none;
  color: var(--text-body);
  font-size: 0.925rem;
  line-height: 1.6;
}

.faq-item.open .faq-content {
  display: block;
}

/* ==========================================================================
   Contact & Footer
   ========================================================================== */
.contact-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-primary);
  border-radius: var(--radius-lg);
  padding: 3rem 2rem;
  text-align: center;
  max-width: 840px;
  margin-inline: auto;
  box-shadow: var(--shadow-card);
}

.contact-title {
  font-size: clamp(1.75rem, 3.5vw, 2.2rem);
  margin-bottom: 0.75rem;
  color: var(--text-main);
}

.contact-desc {
  max-width: 580px;
  margin-inline: auto;
  margin-bottom: 1.75rem;
  font-size: 1.05rem;
}

.contact-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 1.5rem;
  margin-bottom: 1.75rem;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--text-body);
}

.contact-meta span {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--text-main);
  color: #ffffff;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: 0.85rem;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  box-shadow: 0 10px 25px rgba(15, 23, 42, 0.25);
  transition: transform var(--transition-normal);
  z-index: 1000;
  pointer-events: none;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
}

.back-to-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--bg-surface);
  border: 1px solid var(--border-medium);
  color: var(--text-main);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 90;
  opacity: 0;
  pointer-events: none;
  transition: all var(--transition-normal);
  box-shadow: var(--shadow-sm);
}

.back-to-top.visible {
  opacity: 1;
  pointer-events: auto;
}

.back-to-top:hover {
  background: var(--accent-primary);
  color: #ffffff;
  border-color: var(--accent-primary);
}

.site-footer {
  border-top: 1px solid var(--border-subtle);
  padding: 2.5rem 0;
  background: var(--bg-surface);
  margin-top: 2rem;
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 1rem;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.footer-nav {
  display: flex;
  gap: 1.25rem;
  flex-wrap: wrap;
}

.footer-nav a {
  color: var(--text-body);
}

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

/* ==========================================================================
   Responsive Breakpoints & Mobile Hardening
   ========================================================================== */
@media (max-width: 980px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }
  .projects-grid {
    grid-template-columns: 1fr;
  }
  .courses-grid {
    grid-template-columns: 1fr;
  }
  .skills-grid {
    grid-template-columns: 1fr;
  }
  .workflow-chain {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 768px) {
  .container {
    width: min(100% - 1.5rem, 1180px);
  }

  .site-nav {
    position: relative;
    width: 100%;
  }

  .nav-brand {
    max-width: calc(100% - 48px);
    overflow: hidden;
  }

  .brand-text {
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .brand-sub {
    display: none;
  }

  .nav-menu {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: stretch;
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-medium);
    padding: 1.25rem;
    gap: 0.5rem;
    box-shadow: 0 20px 30px rgba(15, 23, 42, 0.15);
    z-index: 999;
  }

  .nav-menu.open {
    display: flex;
  }

  .nav-toggle {
    display: flex !important;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    flex-shrink: 0;
  }

  .hero-title {
    font-size: clamp(1.55rem, 6.8vw, 2.25rem);
    line-height: 1.15;
    word-break: normal;
    overflow-wrap: break-word;
  }

  .hero-actions {
    flex-direction: column;
    align-items: stretch;
  }

  .hero-actions .btn {
    width: 100%;
    text-align: center;
  }

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

  .workflow-chain {
    grid-template-columns: 1fr;
  }

  .contact-meta {
    flex-direction: column;
    align-items: center;
    gap: 0.5rem;
    word-break: break-all;
  }

  .deepdive-row {
    flex-direction: column;
    gap: 0.2rem;
  }

  .deepdive-label {
    min-width: auto;
  }
}

@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;
  }
}