/**
 * CORE STYLESHEET — TRAN BUI HOANG KIM PORTFOLIO
 * Framework-free, high-performance, accessible CSS
 */

@import url('tokens.css');

/* ==========================================================================
   1. RESET & BASE
   ========================================================================== */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  background-color: var(--color-bg-primary);
  color: var(--color-text-primary);
  font-family: var(--font-sans);
  font-size: var(--text-body);
  line-height: var(--leading-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
  text-rendering: optimizeLegibility;
}

/* Accessibility: Skip Link */
.skip-link {
  position: absolute;
  top: -100px;
  left: 16px;
  background: var(--color-navy-primary);
  color: var(--color-text-inverse);
  padding: 8px 16px;
  font-size: var(--text-body-sm);
  font-weight: 600;
  border-radius: var(--radius-sm);
  z-index: 1000;
  text-decoration: none;
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 16px;
  outline: 2px solid var(--color-accent-blue);
}

/* Focus Visible */
:focus-visible {
  outline: 2px solid var(--color-accent-blue);
  outline-offset: 3px;
}

/* Headings */
h1, h2, h3, h4 {
  color: var(--color-navy-primary);
  font-family: var(--font-sans);
  font-weight: 700;
  line-height: var(--leading-tight);
  letter-spacing: -0.02em;
}

p {
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
}

a {
  color: inherit;
  text-decoration: none;
}

code {
  font-family: var(--font-mono);
  font-size: 0.88em;
  background: var(--color-bg-subtle);
  color: var(--color-navy-primary);
  padding: 2px 6px;
  border-radius: var(--radius-xs);
  border: 1px solid var(--color-border-subtle);
  overflow-wrap: anywhere;
  word-break: break-word;
}

/* Safety net: media & long content never force horizontal overflow on mobile */
img, svg, video, canvas { max-width: 100%; height: auto; }

/* ==========================================================================
   2. LAYOUT UTILITIES
   ========================================================================== */

.container {
  width: 100%;
  max-width: var(--container-max);
  margin-left: auto;
  margin-right: auto;
  padding-left: var(--container-padding);
  padding-right: var(--container-padding);
}

.content-narrow {
  max-width: var(--content-max);
}

.section {
  padding-top: var(--space-20);
  padding-bottom: var(--space-20);
}

.section-alt {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
}

.section-header {
  margin-bottom: var(--space-12);
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-navy-secondary);
  margin-bottom: var(--space-2);
}

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

.section-title {
  font-size: var(--text-h2);
  margin-bottom: var(--space-3);
}

.section-subtitle {
  font-size: var(--text-body);
  color: var(--color-text-secondary);
  max-width: 680px;
}

/* ==========================================================================
   3. NAVIGATION HEADER
   ========================================================================== */

.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.94);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid var(--color-border-subtle);
  transition: border-color var(--transition-fast);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.brand-link {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-weight: 700;
  font-size: var(--text-body-sm);
  color: var(--color-navy-primary);
  letter-spacing: -0.01em;
}

.brand-monogram {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 34px;
  height: 34px;
  background-color: var(--color-navy-primary);
  color: var(--color-text-inverse);
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  border-radius: var(--radius-sm);
}

.brand-name {
  display: flex;
  flex-direction: column;
}

.brand-title {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  list-style: none;
}

.nav-link {
  font-size: var(--text-body-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  padding: var(--space-2) 0;
  position: relative;
}

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

.nav-link.active::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-navy-primary);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

.lang-switcher {
  display: inline-flex;
  align-items: center;
  background-color: var(--color-bg-subtle);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-sm);
  padding: 2px;
  gap: 2px;
}

.lang-btn {
  background: transparent;
  border: none;
  font-family: var(--font-mono);
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  padding: 4px 8px;
  border-radius: var(--radius-xs);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.lang-btn:hover {
  color: var(--color-navy-primary);
}

.lang-btn.active {
  background-color: var(--color-navy-primary);
  color: var(--color-text-inverse);
}

/* Mobile Hamburger Button */
.mobile-menu-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  width: 40px;
  height: 40px;
  background: transparent;
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 8px;
  gap: 5px;
  transition: all var(--transition-fast);
  z-index: 101;
}

.mobile-menu-toggle:hover {
  background-color: var(--color-bg-subtle);
  border-color: var(--color-border-strong);
}

.mobile-menu-toggle span {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-navy-primary);
  border-radius: 1px;
  transition: transform 0.25s ease, opacity 0.2s ease;
}

.mobile-menu-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.mobile-menu-toggle.active span:nth-child(2) {
  opacity: 0;
  transform: scaleX(0);
}

.mobile-menu-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Nav Backdrop & Drawer */
.mobile-nav-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(11, 23, 57, 0.45);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 998;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

.mobile-nav-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav-drawer {
  position: fixed;
  top: 0;
  right: 0;
  width: 290px;
  max-width: 85vw;
  height: 100vh;
  background-color: var(--color-bg-primary);
  z-index: 999;
  box-shadow: -4px 0 24px rgba(0, 0, 0, 0.15);
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
  padding: var(--space-6) var(--space-5);
  overflow-y: auto;
}

.mobile-nav-drawer.active {
  transform: translateX(0);
}

.mobile-drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border-subtle);
  margin-bottom: var(--space-4);
}

.mobile-drawer-title {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 700;
  color: var(--color-navy-primary);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.mobile-nav-links {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  list-style: none;
  margin-bottom: auto;
}

.mobile-nav-link {
  display: flex;
  align-items: center;
  padding: 10px 14px;
  font-size: 0.98rem;
  font-weight: 600;
  color: var(--color-navy-primary);
  border-radius: var(--radius-sm);
  transition: all var(--transition-fast);
}

.mobile-nav-link:hover,
.mobile-nav-link.active {
  background-color: var(--color-bg-subtle);
  color: var(--color-accent-blue);
}

.mobile-drawer-footer {
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border-subtle);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

body.menu-open {
  overflow: hidden;
  touch-action: none;
}

/* ==========================================================================
   4. BUTTONS & UI CONTROLS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: 10px 18px;
  border-radius: var(--radius-sm);
  font-size: var(--text-body-sm);
  font-weight: 600;
  line-height: 1;
  cursor: pointer;
  text-decoration: none;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
  white-space: nowrap;
}

.btn svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.btn-primary {
  background-color: var(--color-navy-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-navy-primary);
}

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

.btn-secondary {
  background-color: var(--color-bg-primary);
  color: var(--color-navy-primary);
  border-color: var(--color-border-medium);
}

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

.btn-subtle {
  background-color: transparent;
  color: var(--color-text-secondary);
  border-color: transparent;
  padding: 8px 12px;
}

.btn-subtle:hover {
  color: var(--color-navy-primary);
  background-color: var(--color-bg-subtle);
}

.btn-sm {
  padding: 6px 12px;
  font-size: var(--text-caption);
}

/* Status Pill */
.status-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: 4px 12px;
  background-color: var(--color-accent-emerald-subtle);
  color: var(--color-accent-emerald);
  border: 1px solid rgba(13, 148, 136, 0.2);
  border-radius: var(--radius-full);
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  font-weight: 500;
}

.status-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent-emerald);
}

/* ==========================================================================
   5. HERO SECTION
   ========================================================================== */

.hero {
  padding-top: var(--space-20);
  padding-bottom: var(--space-16);
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: var(--space-12);
  align-items: center;
}

.hero-content {
  display: flex;
  flex-direction: column;
}

.hero-headline {
  font-size: var(--text-hero);
  color: var(--color-navy-primary);
  margin-top: var(--space-4);
  margin-bottom: var(--space-6);
  letter-spacing: -0.03em;
}

.hero-headline-accent {
  color: var(--color-navy-secondary);
}

.hero-lead {
  font-size: clamp(1.05rem, 1.8vw, 1.2rem);
  color: var(--color-text-secondary);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-8);
  max-width: 640px;
}

.hero-actions {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  flex-wrap: wrap;
  margin-bottom: var(--space-10);
}

.hero-socials {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px solid var(--color-border-subtle);
}

.social-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
}

.social-link:hover {
  color: var(--color-navy-primary);
}

/* Hero Right Visual: Minimal Engineering Card */
.hero-visual {
  position: relative;
}

.profile-card {
  background: var(--color-bg-primary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-card);
}

.profile-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding-bottom: var(--space-5);
  border-bottom: 1px solid var(--color-border-subtle);
  margin-bottom: var(--space-5);
}

.profile-avatar {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-md);
  object-fit: cover;
  border: 1px solid var(--color-border-medium);
  background-color: var(--color-bg-subtle);
}

.profile-meta-name {
  font-size: var(--text-h4);
  font-weight: 700;
  color: var(--color-navy-primary);
}

.profile-meta-sub {
  font-size: var(--text-caption);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

.profile-fact-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  list-style: none;
}

.profile-fact-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-body-sm);
}

.profile-fact-label {
  color: var(--color-text-muted);
  font-size: var(--text-caption);
  font-family: var(--font-mono);
}

.profile-fact-value {
  font-weight: 600;
  color: var(--color-navy-primary);
  font-family: var(--font-mono);
}

/* ==========================================================================
   6. PROOF STRIP / METRICS
   ========================================================================== */

.proof-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border-subtle);
  border-bottom: 1px solid var(--color-border-subtle);
  background-color: var(--color-bg-secondary);
}

.proof-card {
  padding: 0 var(--space-4);
  border-right: 1px solid var(--color-border-subtle);
}

.proof-card:last-child {
  border-right: none;
}

.proof-value {
  font-family: var(--font-mono);
  font-size: 1.65rem;
  font-weight: 700;
  color: var(--color-navy-primary);
  letter-spacing: -0.03em;
  margin-bottom: var(--space-1);
}

.proof-label {
  font-size: var(--text-caption);
  color: var(--color-text-secondary);
  font-weight: 500;
  line-height: var(--leading-snug);
}

/* ==========================================================================
   7. SELECTED WORK SECTION
   ========================================================================== */

.projects-filter {
  display: flex;
  gap: var(--space-2);
  margin-bottom: var(--space-8);
  flex-wrap: wrap;
}

.filter-btn {
  padding: 6px 14px;
  background-color: transparent;
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-sm);
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.filter-btn:hover {
  background-color: var(--color-bg-subtle);
  color: var(--color-navy-primary);
}

.filter-btn.active {
  background-color: var(--color-navy-primary);
  color: var(--color-text-inverse);
  border-color: var(--color-navy-primary);
}

.projects-stack {
  display: flex;
  flex-direction: column;
  gap: var(--space-10);
}

.project-card {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  box-shadow: var(--shadow-card);
  transition: border-color var(--transition-normal), box-shadow var(--transition-normal);
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-6);
}

.project-card:hover {
  border-color: var(--color-border-medium);
  box-shadow: var(--shadow-hover);
}

.project-meta-top {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}

.project-category-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: 3px 8px;
  border-radius: var(--radius-xs);
}

.tag-production {
  background-color: var(--color-accent-emerald-subtle);
  color: var(--color-accent-emerald);
  border: 1px solid rgba(13, 148, 136, 0.2);
}

.tag-security {
  background-color: var(--color-accent-blue-subtle);
  color: var(--color-accent-blue);
  border: 1px solid rgba(2, 132, 199, 0.2);
}

.tag-lab {
  background-color: var(--color-accent-amber-subtle);
  color: var(--color-accent-amber);
  border: 1px solid rgba(217, 119, 6, 0.2);
}

.project-scope {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  color: var(--color-text-muted);
}

.project-title {
  font-size: var(--text-h3);
  margin-bottom: var(--space-2);
}

.project-title a {
  color: var(--color-navy-primary);
  transition: color var(--transition-fast);
}

.project-title a:hover {
  color: var(--color-navy-secondary);
}

.project-one-line {
  font-size: var(--text-body);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-4);
  line-height: var(--leading-normal);
}

.project-contribution-box {
  background-color: var(--color-bg-secondary);
  border-left: 3px solid var(--color-navy-primary);
  padding: var(--space-4) var(--space-5);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  margin-bottom: var(--space-5);
}

.contribution-label {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  font-weight: 700;
  color: var(--color-navy-primary);
  margin-bottom: var(--space-1);
  display: block;
}

.contribution-text {
  font-size: var(--text-body-sm);
  color: var(--color-text-secondary);
}

.project-highlights-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  margin-bottom: var(--space-6);
}

.project-highlights-list li {
  font-size: var(--text-body-sm);
  color: var(--color-text-secondary);
  position: relative;
  padding-left: var(--space-5);
  line-height: var(--leading-normal);
}

.project-highlights-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--color-accent-blue);
  font-weight: bold;
}

.project-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--space-5);
  border-top: 1px solid var(--color-border-subtle);
  flex-wrap: wrap;
  gap: var(--space-4);
}

.tech-pills {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.tech-pill {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 3px 8px;
  background-color: var(--color-bg-subtle);
  color: var(--color-navy-primary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-xs);
}

/* ==========================================================================
   8. INTERACTIVE GRC / ISO 27005 WIDGET
   ========================================================================== */

.interactive-widget {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  box-shadow: var(--shadow-card);
}

.widget-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: var(--space-8);
  margin-top: var(--space-6);
}

.widget-controls {
  display: flex;
  flex-direction: column;
  gap: var(--space-5);
}

.control-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.control-label-row {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.control-label {
  font-size: var(--text-body-sm);
  font-weight: 600;
  color: var(--color-navy-primary);
}

.control-badge {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  color: var(--color-accent-blue);
  font-weight: 700;
}

.slider-input {
  width: 100%;
  height: 6px;
  background: var(--color-bg-subtle);
  border-radius: var(--radius-full);
  outline: none;
  accent-color: var(--color-navy-primary);
  cursor: pointer;
}

.widget-results {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--space-5);
}

.result-card {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-bottom: var(--space-4);
  border-bottom: 1px solid var(--color-border-subtle);
}

.result-card:last-child {
  border-bottom: none;
  padding-bottom: 0;
}

.result-title {
  font-size: var(--text-body-sm);
  font-weight: 600;
  color: var(--color-navy-primary);
}

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

.result-value-badge {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: var(--radius-sm);
}

.risk-high {
  color: var(--color-accent-red);
  background-color: rgba(220, 38, 38, 0.08);
}

.risk-med {
  color: var(--color-accent-amber);
  background-color: var(--color-accent-amber-subtle);
}

.risk-low {
  color: var(--color-accent-emerald);
  background-color: var(--color-accent-emerald-subtle);
}

/* ==========================================================================
   9. SKILLS & TECHNICAL DEPTH
   ========================================================================== */

.skills-matrix {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

.skill-category-card {
  background-color: var(--color-bg-primary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-6);
}

.skill-category-title {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  font-weight: 700;
  color: var(--color-navy-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--space-4);
  padding-bottom: var(--space-2);
  border-bottom: 1px solid var(--color-border-subtle);
}

.skill-items-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.skill-items-list li {
  font-size: var(--text-body-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-snug);
}

/* ==========================================================================
   10. EXPERIENCE & LEADERSHIP TIMELINE
   ========================================================================== */

.timeline {
  position: relative;
  border-left: 2px solid var(--color-border-subtle);
  margin-left: var(--space-3);
  padding-left: var(--space-8);
  display: flex;
  flex-direction: column;
  gap: var(--space-10);
}

.timeline-item {
  position: relative;
}

.timeline-node {
  position: absolute;
  left: calc(-1 * var(--space-8) - 6px);
  top: 4px;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background-color: var(--color-navy-primary);
  border: 2px solid var(--color-bg-primary);
}

.timeline-header {
  margin-bottom: var(--space-2);
}

.timeline-role {
  font-size: var(--text-h4);
  font-weight: 700;
  color: var(--color-navy-primary);
}

.timeline-org {
  font-family: var(--font-mono);
  font-size: var(--text-caption);
  color: var(--color-text-muted);
}

.timeline-desc {
  font-size: var(--text-body-sm);
  color: var(--color-text-secondary);
}

/* ==========================================================================
   11. ABOUT & PRINCIPLES
   ========================================================================== */

.about-grid {
  display: grid;
  grid-template-columns: 1.2fr 0.8fr;
  gap: var(--space-10);
  align-items: start;
}

.about-text {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.principles-box {
  background-color: var(--color-bg-secondary);
  border: 1px solid var(--color-border-subtle);
  border-radius: var(--radius-md);
  padding: var(--space-6);
}

.principles-title {
  font-size: var(--text-body-sm);
  font-weight: 700;
  color: var(--color-navy-primary);
  margin-bottom: var(--space-3);
}

.principles-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.principles-list li {
  font-size: var(--text-body-sm);
  color: var(--color-text-secondary);
  line-height: var(--leading-snug);
}

.principles-list strong {
  color: var(--color-navy-primary);
}

/* ==========================================================================
   12. CONTACT & FOOTER
   ========================================================================== */

.contact-section {
  padding-top: var(--space-24);
  padding-bottom: var(--space-24);
  text-align: center;
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border-subtle);
}

.contact-inner {
  max-width: 640px;
  margin: 0 auto;
}

.contact-headline {
  font-size: var(--text-h2);
  margin-bottom: var(--space-3);
}

.contact-desc {
  font-size: var(--text-body);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
}

.contact-actions {
  display: flex;
  justify-content: center;
  align-items: stretch;
  gap: var(--space-4);
  flex-wrap: nowrap;
  width: max-content;
  max-width: 100%;
  margin-inline: auto;
}

.contact-actions .btn {
  white-space: nowrap;
}

@media (max-width: 640px) {
  .contact-actions {
    flex-direction: column;
    width: 100%;
    max-width: 320px;
  }
  .contact-actions .btn {
    width: 100%;
    justify-content: center;
  }
}

.site-footer {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-border-subtle);
  background-color: var(--color-bg-primary);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-caption);
  color: var(--color-text-muted);
  flex-wrap: wrap;
  gap: var(--space-4);
}

.footer-links {
  display: flex;
  gap: var(--space-5);
  list-style: none;
}

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

.footer-link:hover {
  color: var(--color-navy-primary);
}

/* ==========================================================================
   13. RESPONSIVE BREAKPOINTS & MOBILE OPTIMIZATION
   ========================================================================== */

@media (max-width: 1024px) {
  .skills-matrix {
    grid-template-columns: repeat(2, 1fr);
  }
  .proof-strip {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-6);
  }
  .proof-card:nth-child(2) {
    border-right: none;
  }
  .widget-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  /* Navigation */
  .nav-menu {
    display: none;
  }
  
  .nav-actions .btn-secondary {
    display: none; /* Hide header PDF button on mobile, available in mobile drawer */
  }

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

  .nav-inner {
    height: 64px;
  }

  /* Typography */
  .section-title {
    font-size: clamp(1.5rem, 5vw, 1.85rem);
  }

  /* Hero Section */
  .hero {
    padding-top: var(--space-8);
    padding-bottom: var(--space-12);
  }

  .hero-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .hero-headline {
    font-size: clamp(1.85rem, 6.5vw, 2.5rem);
    line-height: 1.15;
  }

  .hero-lead {
    font-size: 0.98rem;
  }

  .hero-actions {
    flex-direction: column;
    width: 100%;
    gap: var(--space-3);
  }

  .hero-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .hero-socials {
    flex-wrap: wrap;
    gap: var(--space-3);
  }

  .profile-card {
    margin-top: var(--space-4);
  }

  /* Proof Strip */
  .proof-strip {
    grid-template-columns: 1fr;
    gap: var(--space-4);
    padding: var(--space-5);
  }

  .proof-card {
    border-right: none;
    border-bottom: 1px solid var(--color-border-subtle);
    padding-bottom: var(--space-4);
    padding-right: 0;
  }

  .proof-card:last-child {
    border-bottom: none;
    padding-bottom: 0;
  }

  /* Project Filtering Tabs */
  .project-filters {
    display: flex;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    padding-bottom: 6px;
    margin-bottom: var(--space-6);
    scrollbar-width: none;
    gap: 8px;
    justify-content: flex-start;
  }

  .project-filters::-webkit-scrollbar {
    display: none;
  }

  .filter-btn {
    flex-shrink: 0;
    white-space: nowrap;
    font-size: 0.8rem;
    padding: 6px 12px;
  }

  /* Project Cards */
  .project-card {
    padding: var(--space-5);
    gap: var(--space-4);
  }

  .project-title {
    font-size: 1.15rem;
  }

  .project-contribution-box {
    padding: var(--space-4);
  }

  .project-footer {
    flex-direction: column;
    align-items: stretch;
    gap: var(--space-4);
  }

  .project-footer .btn {
    width: 100%;
    justify-content: center;
  }

  .tech-pills {
    justify-content: flex-start;
  }

  /* Interactive GRC Demo (#demo) */
  .demo-widget {
    padding: var(--space-5);
  }

  .calc-results-grid {
    grid-template-columns: 1fr;
    gap: var(--space-3);
  }

  .calc-operator {
    display: none; /* Hide multiplication glyphs on stacked mobile layout */
  }

  /* Technical Skills Matrix */
  .skills-matrix {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }

  .skill-group-card {
    padding: var(--space-5);
  }

  /* Experience Timeline */
  .timeline-wrapper {
    padding-left: 20px;
  }

  .timeline-item::before {
    left: -21px;
  }

  .timeline-item {
    padding-bottom: var(--space-8);
  }

  .timeline-header {
    flex-direction: column;
    gap: 2px;
  }

  /* About Section */
  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-6);
  }

  .principles-card {
    padding: var(--space-5);
  }

  /* Contact & Footer */
  .contact-section {
    padding-top: var(--space-16);
    padding-bottom: var(--space-16);
  }

  .contact-headline {
    font-size: clamp(1.4rem, 5vw, 1.85rem);
  }

  .contact-actions {
    flex-direction: column;
    width: 100%;
    max-width: 100%;
  }

  .contact-actions .btn {
    width: 100%;
    justify-content: center;
  }

  .footer-inner {
    flex-direction: column;
    text-align: center;
    gap: var(--space-4);
  }

  .footer-links {
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--space-4);
  }
}

@media (max-width: 480px) {
  :root {
    --container-padding: 16px;
  }

  .brand-name span:first-child {
    font-size: 0.85rem;
  }

  .brand-title {
    font-size: 0.68rem;
  }

  .hero-status-badge {
    font-size: 0.72rem;
    padding: 3px 8px;
  }

  .profile-card-header {
    gap: var(--space-3);
  }

  .profile-avatar {
    width: 44px;
    height: 44px;
  }

  .profile-fact-list {
    gap: var(--space-2);
  }

  .proof-value {
    font-size: 1.5rem;
  }

  .proof-label {
    font-size: 0.78rem;
  }

  .tech-pill {
    font-size: 0.72rem;
    padding: 2px 7px;
  }
}