/* =============================================
   DESIGN TOKENS — Technical / Developer aesthetic
   Dark palette with teal accent, monospace display
   ============================================= */

: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);
  --text-hero: clamp(3rem, 0.5rem + 7vw, 8rem);

  /* 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;
  --content-full: 100%;

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

/* =============================================
   DARK THEME (default)
   ============================================= */
:root,
[data-theme='dark'] {
  --color-bg: #0a0e17;
  --color-surface: #0f1520;
  --color-surface-2: #151d2c;
  --color-surface-offset: #111826;
  --color-surface-offset-2: #1a2332;
  --color-surface-dynamic: #1e2a3a;
  --color-divider: #1e2a3a;
  --color-border: #273345;

  --color-text: #e0e6ef;
  --color-text-muted: #7a8ba0;
  --color-text-faint: #4a5568;
  --color-text-inverse: #0a0e17;

  --color-primary: #22d3ee;
  --color-primary-hover: #06b6d4;
  --color-primary-active: #0891b2;
  --color-primary-highlight: rgba(34, 211, 238, 0.1);

  --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 THEME
   ============================================= */
[data-theme='light'] {
  --color-bg: #f4f6f9;
  --color-surface: #ffffff;
  --color-surface-2: #f9fafb;
  --color-surface-offset: #eef1f5;
  --color-surface-offset-2: #e5e9f0;
  --color-surface-dynamic: #dce1ea;
  --color-divider: #d1d9e6;
  --color-border: #c4cdd9;

  --color-text: #0f172a;
  --color-text-muted: #64748b;
  --color-text-faint: #94a3b8;
  --color-text-inverse: #f8fafc;

  --color-primary: #0891b2;
  --color-primary-hover: #0e7490;
  --color-primary-active: #155e75;
  --color-primary-highlight: rgba(8, 145, 178, 0.08);

  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.06);
  --shadow-md: 0 4px 12px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 12px 32px rgba(15, 23, 42, 0.12);
}

/* =============================================
   LAYOUT
   ============================================= */
.container {
  max-width: var(--content-wide);
  margin-inline: auto;
  padding-inline: var(--space-4);
}

@media (min-width: 768px) {
  .container {
    padding-inline: var(--space-8);
  }
}

/* =============================================
   HEADER / NAV
   ============================================= */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(10, 14, 23, 0.85);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-divider);
  transition: box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

[data-theme='light'] .header {
  background: rgba(244, 246, 249, 0.88);
}

.header--scrolled {
  box-shadow: var(--shadow-md);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  text-decoration: none;
  color: var(--color-text);
}

.logo__icon {
  color: var(--color-primary);
}

.logo__text {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.nav {
  display: none;
  align-items: center;
  gap: var(--space-6);
}

@media (min-width: 768px) {
  .nav {
    display: flex;
  }
}

.nav__link {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  position: relative;
  padding-block: var(--space-1);
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.nav__link:hover::after {
  width: 100%;
}

.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  color: var(--color-text-muted);
  transition: color var(--transition-interactive), background var(--transition-interactive);
}

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

/* Mobile nav */
.mobile-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  color: var(--color-text);
}

@media (min-width: 768px) {
  .mobile-toggle {
    display: none;
  }
}

.mobile-nav {
  display: none;
  position: fixed;
  inset: 64px 0 0 0;
  background: var(--color-bg);
  padding: var(--space-8) var(--space-4);
  z-index: 40;
  flex-direction: column;
  gap: var(--space-6);
}

.mobile-nav.is-open {
  display: flex;
}

.mobile-nav__link {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-divider);
}

.mobile-nav__link:hover {
  color: var(--color-primary);
}

/* =============================================
   HERO
   ============================================= */
.hero {
  position: relative;
  min-height: 90vh;
  display: flex;
  align-items: center;
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.4;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    rgba(10, 14, 23, 0.7) 0%,
    rgba(10, 14, 23, 0.9) 100%
  );
}

[data-theme='light'] .hero__overlay {
  background: linear-gradient(
    180deg,
    rgba(244, 246, 249, 0.7) 0%,
    rgba(244, 246, 249, 0.92) 100%
  );
}

[data-theme='light'] .hero__bg img {
  opacity: 0.25;
}

.hero__content {
  position: relative;
  z-index: 1;
  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);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: var(--space-6);
  padding: var(--space-1) var(--space-3);
  border: 1px solid var(--color-primary);
  border-radius: var(--radius-full);
}

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

@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.hero__title {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-4);
  line-height: 1.05;
}

.hero__title .accent {
  color: var(--color-primary);
}

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

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-md);
  text-decoration: none;
  transition: all var(--transition-interactive);
  min-height: 44px;
}

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

.btn--primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 0 20px rgba(34, 211, 238, 0.3);
}

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

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

/* Terminal cursor blink */
.cursor {
  display: inline-block;
  width: 3px;
  height: 1em;
  background: var(--color-primary);
  margin-left: var(--space-1);
  animation: blink 1s step-end infinite;
  vertical-align: text-bottom;
}

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

/* =============================================
   SECTION BASE
   ============================================= */
.section {
  padding: clamp(var(--space-12), 8vw, var(--space-24)) 0;
}

.section__header {
  margin-bottom: clamp(var(--space-8), 4vw, var(--space-16));
}

.section__label {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-transform: uppercase;
  letter-spacing: 0.15em;
  margin-bottom: var(--space-2);
}

.section__title {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
}

/* =============================================
   ABOUT
   ============================================= */
.about__grid {
  display: grid;
  gap: var(--space-10);
  align-items: center;
}

@media (min-width: 768px) {
  .about__grid {
    grid-template-columns: 300px 1fr;
    gap: var(--space-12);
  }
}

.about__image-wrap {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--color-border);
}

.about__image-wrap::after {
  content: '';
  position: absolute;
  inset: 0;
  border: 1px solid rgba(34, 211, 238, 0.15);
  border-radius: var(--radius-lg);
  pointer-events: none;
}

.about__image-wrap img {
  width: 100%;
  aspect-ratio: 1;
  object-fit: cover;
}

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

.about__text p strong {
  color: var(--color-text);
  font-weight: 600;
}

/* Stats row */
.stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-4);
  margin-top: var(--space-8);
}

.stat {
  text-align: center;
  padding: var(--space-4);
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
}

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

.stat__label {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

/* =============================================
   SKILLS / TECH STACK
   ============================================= */
.skills__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(min(280px, 100%), 1fr));
  gap: var(--space-4);
}

.skill-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  position: relative;
  overflow: hidden;
}

.skill-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-primary), transparent);
  opacity: 0;
  transition: opacity 0.3s;
}

.skill-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md), 0 0 20px rgba(34, 211, 238, 0.05);
  transform: translateY(-2px);
}

.skill-card:hover::before {
  opacity: 1;
}

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

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

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

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

/* =============================================
   PROJECTS
   ============================================= */
.projects__grid {
  display: grid;
  gap: var(--space-6);
}

@media (min-width: 768px) {
  .projects__grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

.project-card__image {
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  border-bottom: 1px solid var(--color-divider);
}

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

.project-card__title {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

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

.project-card__tech {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.project-card__links {
  display: flex;
  gap: var(--space-3);
}

.project-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-primary);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.project-link:hover {
  text-decoration: underline;
}

/* =============================================
   FULL-BLEED IMAGE DIVIDER
   ============================================= */
.image-divider {
  width: 100%;
  height: 300px;
  position: relative;
  overflow: hidden;
}

.image-divider img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.image-divider::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(
    180deg,
    var(--color-bg) 0%,
    transparent 30%,
    transparent 70%,
    var(--color-bg) 100%
  );
}

/* =============================================
   CONTACT
   ============================================= */
.contact__inner {
  max-width: var(--content-narrow);
  margin-inline: auto;
  text-align: center;
}

.contact__desc {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  line-height: 1.7;
}

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

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  text-decoration: none;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  padding: var(--space-3) var(--space-5);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-interactive);
  min-height: 44px;
}

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

/* =============================================
   FOOTER
   ============================================= */
.footer {
  padding: var(--space-8) 0;
  border-top: 1px solid var(--color-divider);
}

.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
}

@media (min-width: 768px) {
  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
  }
}

.footer__text {
  font-family: var(--font-display);
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  letter-spacing: 0.04em;
}

.footer__text .accent {
  color: var(--color-primary);
}

/* =============================================
   SCROLL ANIMATIONS (fade in)
   ============================================= */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* Staggered children */
.fade-in-children > * {
  opacity: 0;
  transform: translateY(16px);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.fade-in-children.is-visible > *:nth-child(1) { transition-delay: 0ms; opacity: 1; transform: translateY(0); }
.fade-in-children.is-visible > *:nth-child(2) { transition-delay: 80ms; opacity: 1; transform: translateY(0); }
.fade-in-children.is-visible > *:nth-child(3) { transition-delay: 160ms; opacity: 1; transform: translateY(0); }
.fade-in-children.is-visible > *:nth-child(4) { transition-delay: 240ms; opacity: 1; transform: translateY(0); }
.fade-in-children.is-visible > *:nth-child(5) { transition-delay: 320ms; opacity: 1; transform: translateY(0); }
.fade-in-children.is-visible > *:nth-child(6) { transition-delay: 400ms; opacity: 1; transform: translateY(0); }