/* ============================================================
   DESIGN TOKENS
   ============================================================ */
:root {
  /* Colors */
  --color-bg:           #ffffff;
  --color-bg-subtle:    #f8fafc;
  --color-bg-muted:     #f1f5f9;
  --color-fg:           #0f172a;
  --color-fg-muted:     #475569;
  --color-fg-subtle:    #94a3b8;
  --color-border:       #e2e8f0;
  --color-border-muted: #f1f5f9;

  /* Accent — deep blue */
  --color-primary:      #1d4ed8;
  --color-primary-hover:#1e40af;
  --color-primary-light:#eff6ff;
  --color-primary-mid:  #bfdbfe;

  /* Secondary accent — slate */
  --color-secondary:    #0f172a;

  /* Status colors */
  --color-success:      #059669;
  --color-success-bg:   #ecfdf5;
  --color-warning:      #d97706;
  --color-warning-bg:   #fffbeb;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-display: 'Playfair Display', Georgia, serif;

  --text-xs:   0.75rem;
  --text-sm:   0.875rem;
  --text-base: 1rem;
  --text-lg:   1.125rem;
  --text-xl:   1.25rem;
  --text-2xl:  1.5rem;
  --text-3xl:  1.875rem;
  --text-4xl:  2.25rem;
  --text-5xl:  3rem;

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;

  /* Radius */
  --radius-sm:   0.25rem;
  --radius-md:   0.5rem;
  --radius-lg:   0.75rem;
  --radius-xl:   1rem;
  --radius-2xl:  1.5rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm:  0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md:  0 4px 6px -1px rgb(0 0 0 / 0.07), 0 2px 4px -2px rgb(0 0 0 / 0.05);
  --shadow-lg:  0 10px 15px -3px rgb(0 0 0 / 0.08), 0 4px 6px -4px rgb(0 0 0 / 0.05);
  --shadow-xl:  0 20px 25px -5px rgb(0 0 0 / 0.08), 0 8px 10px -6px rgb(0 0 0 / 0.04);

  /* Transitions */
  --transition-fast:   150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow:   400ms ease;

  /* Layout */
  --container-max: 1200px;
  --header-height: 64px;
}

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

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

body {
  font-family: var(--font-sans);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-fg);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

ul, ol {
  list-style: none;
}

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

/* ============================================================
   LAYOUT UTILITIES
   ============================================================ */
.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

@media (max-width: 640px) {
  .container { padding-inline: var(--space-4); }
}

/* ============================================================
   HEADER / NAV
   ============================================================ */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-normal),
              box-shadow var(--transition-normal);
}

.site-header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.nav-inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-8);
}

.nav-logo {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: -0.02em;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  background: var(--color-primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background var(--transition-fast);
}

.nav-logo:hover {
  background: var(--color-primary-mid);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

.nav-links a {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-fg-muted);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast),
              background var(--transition-fast);
}

.nav-links a:hover {
  color: var(--color-fg);
  background: var(--color-bg-muted);
}

/* ============================================================
   BUTTONS
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: 600;
  line-height: 1;
  transition: background var(--transition-fast),
              color var(--transition-fast),
              box-shadow var(--transition-fast),
              transform var(--transition-fast);
  cursor: pointer;
  white-space: nowrap;
}

.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

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

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

.btn-outline {
  background: transparent;
  color: var(--color-fg-muted);
  border: 1.5px solid var(--color-border);
}

.btn-outline:hover {
  color: var(--color-fg);
  border-color: var(--color-fg-muted);
  background: var(--color-bg-subtle);
}

/* ============================================================
   BADGES
   ============================================================ */
.badge {
  display: inline-flex;
  align-items: center;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  letter-spacing: 0.025em;
  line-height: 1.4;
}

.badge-primary {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.badge-secondary {
  background: var(--color-success-bg);
  color: var(--color-success);
}

.badge-outline {
  background: transparent;
  color: var(--color-fg-muted);
  border: 1px solid var(--color-border);
}

/* ============================================================
   HERO SECTION
   ============================================================ */
.hero {
  padding-top: calc(var(--space-20) + var(--space-4));
  padding-bottom: var(--space-16);
  background: linear-gradient(160deg,
    var(--color-bg) 0%,
    var(--color-bg-subtle) 60%,
    var(--color-primary-light) 100%
  );
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -120px;
  right: -120px;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle,
    rgba(29, 78, 216, 0.06) 0%,
    transparent 70%
  );
  pointer-events: none;
}

.hero-inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: flex;
  align-items: flex-start;
  gap: var(--space-12);
}

/* Avatar */
.hero-image-wrap {
  flex-shrink: 0;
  position: relative;
}

.hero-avatar {
  width: 180px;
  height: 180px;
  border-radius: var(--radius-2xl);
  object-fit: cover;
  border: 3px solid var(--color-border);
  box-shadow: var(--shadow-xl);
}

.hero-verified {
  position: absolute;
  bottom: -12px;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-success-bg);
  color: var(--color-success);
  border: 1.5px solid #a7f3d0;
  border-radius: var(--radius-full);
  padding: var(--space-1) var(--space-3);
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* Hero content */
.hero-content {
  flex: 1;
  min-width: 0;
  padding-top: var(--space-2);
}

.hero-badge-row {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.hero-name {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: 700;
  color: var(--color-fg);
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: var(--space-2);
}

.hero-title {
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.hero-location {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-sm);
  color: var(--color-fg-subtle);
  margin-bottom: var(--space-5);
}

.hero-bio {
  font-size: var(--text-base);
  line-height: 1.75;
  color: var(--color-fg-muted);
  max-width: 600px;
  margin-bottom: var(--space-6);
}

.hero-bio strong {
  color: var(--color-fg);
  font-weight: 600;
}

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

/* Stats bar */
.hero-stats {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  margin-top: var(--space-12);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0;
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}

.stat-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: var(--space-5) var(--space-4);
  gap: var(--space-1);
}

.stat-number {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
}

.stat-label {
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-fg-subtle);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-align: center;
}

.stat-divider {
  width: 1px;
  height: 48px;
  background: var(--color-border);
  flex-shrink: 0;
}

/* ============================================================
   SECTION — SHARED STYLES
   ============================================================ */
.section {
  padding-block: var(--space-20);
}

.section-header {
  text-align: center;
  max-width: 640px;
  margin-inline: auto;
  margin-bottom: var(--space-12);
}

.section-tag {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-3);
}

.section-title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-fg);
  letter-spacing: -0.02em;
  line-height: 1.2;
  margin-bottom: var(--space-4);
}

.section-desc {
  font-size: var(--text-base);
  color: var(--color-fg-muted);
  line-height: 1.7;
}

/* ============================================================
   ABOUT SECTION
   ============================================================ */
.section-about {
  background: var(--color-bg);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 360px;
  gap: var(--space-12);
  align-items: start;
}

.about-text p {
  font-size: var(--text-base);
  line-height: 1.8;
  color: var(--color-fg-muted);
  margin-bottom: var(--space-5);
}

.about-text p:last-child {
  margin-bottom: 0;
}

.about-text strong {
  color: var(--color-fg);
  font-weight: 600;
}

/* Info card */
.about-info-card {
  background: var(--color-bg-subtle);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
}

.info-table {
  width: 100%;
}

.info-row {
  display: grid;
  grid-template-columns: 100px 1fr;
  gap: var(--space-3);
  padding: var(--space-4) var(--space-5);
  border-bottom: 1px solid var(--color-border);
}

.info-row:last-child {
  border-bottom: none;
}

.info-row dt {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-fg-subtle);
  padding-top: 2px;
}

.info-row dd {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-fg);
  line-height: 1.5;
}

/* ============================================================
   EXPERTISE SECTION
   ============================================================ */
.section-expertise {
  background: var(--color-bg-subtle);
}

.expertise-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
}

.expertise-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  transition: box-shadow var(--transition-normal),
              transform var(--transition-normal),
              border-color var(--transition-normal);
}

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

.expertise-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  background: var(--color-primary-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary);
  margin-bottom: var(--space-4);
  flex-shrink: 0;
}

.expertise-card h3 {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-fg);
  margin-bottom: var(--space-3);
  line-height: 1.3;
}

.expertise-card p {
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-fg-muted);
  margin-bottom: var(--space-4);
}

.expertise-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.expertise-tags li {
  font-size: 11px;
  font-weight: 600;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 2px var(--space-2);
  border-radius: var(--radius-sm);
  letter-spacing: 0.01em;
}

/* ============================================================
   CERTIFICATES SECTION
   ============================================================ */
.section-certs {
  background: var(--color-bg);
}

.certs-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-5);
}

.cert-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  transition: box-shadow var(--transition-normal),
              transform var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.cert-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--color-primary-mid);
  transition: background var(--transition-normal);
}

.cert-card:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.cert-card:hover::before {
  background: var(--color-primary);
}

.cert-card--featured::before {
  background: var(--color-primary);
}

.cert-card--featured {
  border-color: var(--color-primary-mid);
  background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-primary-light) 100%);
}

.cert-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}

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

.cert-date {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-fg-subtle);
  background: var(--color-bg-muted);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  white-space: nowrap;
}

.cert-title {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-fg);
  line-height: 1.4;
}

.cert-issuer {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary);
}

.cert-skills {
  font-size: var(--text-sm);
  color: var(--color-fg-muted);
  line-height: 1.5;
  flex: 1;
}

.cert-footer {
  margin-top: auto;
  padding-top: var(--space-3);
  border-top: 1px solid var(--color-border-muted);
}

.cert-id {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: 11px;
  font-weight: 500;
  color: var(--color-success);
  font-family: ui-monospace, 'Cascadia Code', monospace;
  letter-spacing: 0.01em;
}

/* ============================================================
   CONTACT / SOCIAL SECTION
   ============================================================ */
.section-contact {
  background: var(--color-bg-subtle);
}

.contact-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  max-width: 800px;
  margin-inline: auto;
}

.contact-card {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-5);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  transition: box-shadow var(--transition-normal),
              transform var(--transition-normal),
              border-color var(--transition-normal);
  cursor: pointer;
}

.contact-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.contact-card:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

.contact-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.contact-icon--linkedin {
  background: #e8f0fe;
  color: #0a66c2;
}

.contact-icon--x {
  background: #f0f0f0;
  color: #000000;
}

.contact-icon--fb {
  background: #e7f0ff;
  color: #1877f2;
}

.contact-card:hover .contact-icon--linkedin { background: #0a66c2; color: #fff; }
.contact-card:hover .contact-icon--x        { background: #000000; color: #fff; }
.contact-card:hover .contact-icon--fb       { background: #1877f2; color: #fff; }

.contact-info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.contact-platform {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-fg-subtle);
}

.contact-handle {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-fg);
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.contact-arrow {
  color: var(--color-fg-subtle);
  flex-shrink: 0;
  transition: transform var(--transition-fast), color var(--transition-fast);
}

.contact-card:hover .contact-arrow {
  transform: translate(2px, -2px);
  color: var(--color-primary);
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--color-fg);
  color: #94a3b8;
  padding-block: var(--space-10);
}

.footer-inner {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-6);
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.footer-logo {
  font-size: var(--text-xl);
  font-weight: 700;
  color: #ffffff;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-lg);
  background: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.footer-tagline {
  font-size: var(--text-sm);
  color: #64748b;
  line-height: 1.4;
}

.footer-nav {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-1);
}

.footer-nav a {
  font-size: var(--text-sm);
  color: #64748b;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  transition: color var(--transition-fast), background var(--transition-fast);
}

.footer-nav a:hover {
  color: #ffffff;
  background: rgba(255, 255, 255, 0.08);
}

.footer-copy {
  font-size: var(--text-sm);
  color: #475569;
  width: 100%;
  text-align: center;
  padding-top: var(--space-6);
  border-top: 1px solid rgba(255,255,255,0.06);
  margin-top: var(--space-2);
}

/* ============================================================
   SCROLL REVEAL ANIMATION
   ============================================================ */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.section {
  animation: fadeInUp 0.5s ease both;
}

/* Reduced motion */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}

/* ============================================================
   RESPONSIVE — TABLET (max 1024px)
   ============================================================ */
@media (max-width: 1024px) {
  .expertise-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .about-grid {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }

  .about-info-card {
    max-width: 480px;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    max-width: 480px;
  }
}

/* ============================================================
   RESPONSIVE — MOBILE (max 768px)
   ============================================================ */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }

  .hero {
    padding-top: calc(var(--space-12) + var(--space-4));
    padding-bottom: var(--space-12);
  }

  .hero-inner {
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: var(--space-8);
    padding-inline: var(--space-4);
  }

  .hero-badge-row {
    justify-content: center;
  }

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

  .hero-bio {
    text-align: left;
  }

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

  .hero-avatar {
    width: 140px;
    height: 140px;
  }

  .hero-name {
    font-size: var(--text-3xl);
  }

  .hero-stats {
    flex-wrap: wrap;
    padding-inline: var(--space-4);
  }

  .stat-item {
    flex: 1 1 40%;
  }

  .stat-divider {
    display: none;
  }

  .section {
    padding-block: var(--space-12);
  }

  .section-title {
    font-size: var(--text-2xl);
  }

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

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

  .info-row {
    grid-template-columns: 90px 1fr;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--space-5);
  }

  .footer-copy {
    text-align: left;
  }
}

/* ============================================================
   RESPONSIVE — SMALL MOBILE (max 480px)
   ============================================================ */
@media (max-width: 480px) {
  .hero-name {
    font-size: var(--text-2xl);
  }

  .btn {
    padding: var(--space-2) var(--space-4);
    font-size: var(--text-xs);
  }

  .contact-card {
    padding: var(--space-4);
  }

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