/* ============================================
   DESIGN TOKENS — Network Engineer Portfolio
   Dark-first terminal aesthetic with teal accent
   ============================================ */

:root {
  /* Type Scale */
  --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
  --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
  --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
  --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
  --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
  --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);

  /* Spacing (4px base) */
  --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;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);

  /* Content widths */
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;

  /* Fonts */
  --font-display: 'JetBrains Mono', 'Courier New', monospace;
  --font-body: 'General Sans', 'Inter', sans-serif;
}

/* ============================================
   DARK MODE (Default for tech portfolio)
   ============================================ */
:root,
[data-theme='dark'] {
  --color-bg: #0f1117;
  --color-surface: #161822;
  --color-surface-2: #1c1f2e;
  --color-border: #2a2d3e;
  --color-divider: #22253a;

  --color-text: #c9cad6;
  --color-text-muted: #7a7d8e;
  --color-text-faint: #4a4d5e;

  --color-primary: #36d6b7;
  --color-primary-hover: #2bb89d;
  --color-primary-active: #1f9a82;
  --color-primary-highlight: rgba(54, 214, 183, 0.1);

  --color-accent-2: #5b8df9;

  --color-error: #f06292;
  --color-warning: #ffb74d;
  --color-success: #66bb6a;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
}

/* ============================================
   LIGHT MODE
   ============================================ */
[data-theme='light'] {
  --color-bg: #f4f5f7;
  --color-surface: #ffffff;
  --color-surface-2: #eef0f4;
  --color-border: #d1d5db;
  --color-divider: #e5e7eb;

  --color-text: #1a1d2e;
  --color-text-muted: #5a5d6e;
  --color-text-faint: #9a9dae;

  --color-primary: #0d9b83;
  --color-primary-hover: #0a7d69;
  --color-primary-active: #076555;
  --color-primary-highlight: rgba(13, 155, 131, 0.08);

  --color-accent-2: #3b6ce7;

  --color-error: #c62828;
  --color-warning: #e65100;
  --color-success: #2e7d32;

  --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
}

@media (prefers-color-scheme: light) {
  :root:not([data-theme]) {
    --color-bg: #f4f5f7;
    --color-surface: #ffffff;
    --color-surface-2: #eef0f4;
    --color-border: #d1d5db;
    --color-divider: #e5e7eb;
    --color-text: #1a1d2e;
    --color-text-muted: #5a5d6e;
    --color-text-faint: #9a9dae;
    --color-primary: #0d9b83;
    --color-primary-hover: #0a7d69;
    --color-primary-active: #076555;
    --color-primary-highlight: rgba(13, 155, 131, 0.08);
    --color-accent-2: #3b6ce7;
    --color-error: #c62828;
    --color-warning: #e65100;
    --color-success: #2e7d32;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.12);
  }
}

/* ============================================
   LAYOUT
   ============================================ */
.container {
  width: 100%;
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-6);
}

section {
  padding-block: clamp(var(--space-12), 8vw, var(--space-24));
}

/* ============================================
   HEADER / NAV
   ============================================ */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 85%, transparent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  padding-block: var(--space-4);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav__logo svg {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.nav__links {
  display: flex;
  align-items: center;
  gap: var(--space-6);
  list-style: none;
}

.nav__links a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-size: var(--text-sm);
  font-weight: 500;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

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

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

.theme-toggle {
  color: var(--color-text-muted);
  padding: var(--space-2);
  border-radius: var(--radius-md);
}

.theme-toggle:hover {
  color: var(--color-primary);
  background: var(--color-primary-highlight);
}

/* Mobile nav */
.mobile-toggle {
  display: none;
  color: var(--color-text);
  padding: var(--space-2);
}

@media (max-width: 768px) {
  .mobile-toggle {
    display: block;
  }
  .nav__links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--space-6);
    gap: var(--space-4);
  }
  .nav__links.active {
    display: flex;
  }
}

/* ============================================
   HERO
   ============================================ */
.hero {
  min-height: 80vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero__content {
  position: relative;
  z-index: 2;
  max-width: 720px;
}

.hero__tag {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  background: var(--color-primary-highlight);
  border: 1px solid color-mix(in srgb, var(--color-primary) 25%, transparent);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--space-6);
  letter-spacing: 0.04em;
}

.hero__tag .dot {
  width: 6px;
  height: 6px;
  background: var(--color-primary);
  border-radius: 50%;
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}

.hero h1 {
  font-family: var(--font-body);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-text);
  line-height: 1.08;
  margin-bottom: var(--space-6);
  letter-spacing: -0.03em;
}

.hero h1 .highlight {
  color: var(--color-primary);
}

.hero__desc {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 540px;
  margin-bottom: var(--space-8);
}

.hero__actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.hero__grid {
  position: absolute;
  inset: 0;
  z-index: 1;
  opacity: 0.04;
  background-image:
    linear-gradient(var(--color-text-muted) 1px, transparent 1px),
    linear-gradient(90deg, var(--color-text-muted) 1px, transparent 1px);
  background-size: 60px 60px;
}

/* ============================================
   BUTTONS
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: 600;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  border: none;
}

.btn--primary {
  background: var(--color-primary);
  color: #0f1117;
}

[data-theme='light'] .btn--primary {
  color: #ffffff;
}

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

.btn--outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

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

/* ============================================
   SECTION HEADERS
   ============================================ */
.section-header {
  margin-bottom: var(--space-10);
}

.section-label {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  margin-bottom: var(--space-3);
}

.section-title {
  font-family: var(--font-body);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

/* ============================================
   ABOUT
   ============================================ */
.about__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-10);
  align-items: start;
}

@media (max-width: 768px) {
  .about__grid {
    grid-template-columns: 1fr;
  }
}

.about__text p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-4);
  line-height: 1.7;
}

.about__stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  text-align: center;
}

.stat-card__value {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.stat-card__label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

/* ============================================
   SKILLS / TECH STACK
   ============================================ */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-6);
}

.skill-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: border-color var(--transition-interactive),
              box-shadow var(--transition-interactive);
}

.skill-card:hover {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 1px var(--color-primary), var(--shadow-md);
}

.skill-card__icon {
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-highlight);
  border-radius: var(--radius-md);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.skill-card__title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.skill-card__items {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.skill-tag {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  background: var(--color-surface-2);
  border: 1px solid var(--color-divider);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
}

/* ============================================
   PROJECTS
   ============================================ */
.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
  gap: var(--space-6);
}

@media (max-width: 480px) {
  .projects__grid {
    grid-template-columns: 1fr;
  }
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-interactive),
              transform 200ms ease;
}

.project-card:hover {
  border-color: var(--color-primary);
  transform: translateY(-2px);
}

.project-card__visual {
  height: 180px;
  background: var(--color-surface-2);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-6);
  overflow: hidden;
  position: relative;
}

.project-card__visual svg {
  width: 100%;
  height: 100%;
  opacity: 0.6;
}

.project-card__body {
  padding: var(--space-6);
}

.project-card__title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.project-card__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin-bottom: var(--space-4);
}

.project-card__tech {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* ============================================
   CERTIFICATIONS
   ============================================ */
.certs__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.cert-item {
  display: flex;
  align-items: center;
  gap: var(--space-5);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-5) var(--space-6);
  transition: border-color var(--transition-interactive);
}

.cert-item:hover {
  border-color: var(--color-primary);
}

.cert-item__icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-primary-highlight);
  border-radius: var(--radius-md);
  color: var(--color-primary);
}

.cert-item__info {
  flex: 1;
}

.cert-item__name {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}

.cert-item__org {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.cert-item__status {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  padding: var(--space-1) var(--space-3);
  border: 1px solid color-mix(in srgb, var(--color-primary) 30%, transparent);
  border-radius: var(--radius-full);
  white-space: nowrap;
}

.cert-item__status--progress {
  color: var(--color-warning);
  border-color: color-mix(in srgb, var(--color-warning) 30%, transparent);
}

/* ============================================
   EXPERIENCE TIMELINE
   ============================================ */
.timeline {
  position: relative;
  padding-left: var(--space-8);
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: var(--space-8);
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__dot {
  position: absolute;
  left: calc(-1 * var(--space-8) + 2px);
  top: 6px;
  width: 12px;
  height: 12px;
  background: var(--color-primary);
  border: 2px solid var(--color-bg);
  border-radius: 50%;
  z-index: 1;
}

.timeline__date {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  margin-bottom: var(--space-2);
}

.timeline__title {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-1);
}

.timeline__company {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
}

.timeline__desc {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ============================================
   CONTACT
   ============================================ */
.contact__inner {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: clamp(var(--space-8), 5vw, var(--space-16));
  text-align: center;
  max-width: 640px;
  margin-inline: auto;
}

.contact__title {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.contact__desc {
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  margin-inline: auto;
}

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

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  padding: var(--space-2) var(--space-4);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

.contact-link:hover {
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.contact-link svg {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
  border-top: 1px solid var(--color-divider);
  padding-block: var(--space-8);
}

.footer__inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.footer__copy {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

.footer__tech {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}

@media (max-width: 640px) {
  .footer__inner {
    flex-direction: column;
    gap: var(--space-2);
    text-align: center;
  }
}

/* ============================================
   SCROLL ANIMATION
   ============================================ */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.reveal-stagger > * {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}

.reveal-stagger.visible > *:nth-child(1) { transition-delay: 0s; }
.reveal-stagger.visible > *:nth-child(2) { transition-delay: 0.08s; }
.reveal-stagger.visible > *:nth-child(3) { transition-delay: 0.16s; }
.reveal-stagger.visible > *:nth-child(4) { transition-delay: 0.24s; }
.reveal-stagger.visible > *:nth-child(5) { transition-delay: 0.32s; }
.reveal-stagger.visible > *:nth-child(6) { transition-delay: 0.4s; }

.reveal-stagger.visible > * {
  opacity: 1;
  transform: translateY(0);
}

/* Terminal cursor blink */
.cursor {
  display: inline-block;
  width: 2px;
  height: 1em;
  background: var(--color-primary);
  margin-left: 4px;
  animation: blink 1s infinite step-end;
  vertical-align: text-bottom;
}

@keyframes blink {
  50% { opacity: 0; }
}