/* ===========================
   CSS Custom Properties
   =========================== */
:root {
  --color-bg: #0e1117;
  --color-bg-alt: #151921;
  --color-surface: #1a1f2b;
  --color-text: #e8ecf1;
  --color-text-secondary: #8b95a5;
  --color-accent: #c8d1dc;
  --color-accent-hover: #e0e6ed;
  --color-border: #2a3040;
  --color-border-light: #1f2535;

  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;

  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 2rem;
  --space-xl: 3rem;
  --space-2xl: 4rem;

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

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 8px 30px rgba(0,0,0,0.5);

  --nav-height: 64px;
  --max-width: 1120px;

  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-family);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  position: relative;
}

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

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

ul {
  list-style: none;
}

/* ===========================
   Particle Canvas
   =========================== */
.particle-canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 0;
}

/* ===========================
   Layout
   =========================== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  position: relative;
  z-index: 1;
}

.section {
  padding: var(--space-2xl) 0;
  position: relative;
}

.section--alt {
  background-color: rgba(21, 25, 33, 0.7);
  backdrop-filter: blur(2px);
}

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.25rem);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  letter-spacing: -0.02em;
}

.section__subtitle {
  color: var(--color-text-secondary);
  font-size: 1.05rem;
  margin-bottom: var(--space-lg);
  max-width: 600px;
}

/* ===========================
   Navigation
   =========================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: rgba(14, 17, 23, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border-light);
  z-index: 1000;
  transition: box-shadow var(--transition);
}

.nav--scrolled {
  box-shadow: var(--shadow-sm);
}

.nav__container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-md);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--color-text);
  transition: opacity var(--transition);
}

.nav__logo:hover {
  opacity: 0.7;
}

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

.nav__link {
  font-size: 0.9rem;
  font-weight: 450;
  color: var(--color-text-secondary);
  transition: color var(--transition);
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1.5px;
  background: var(--color-text);
  transition: width var(--transition);
}

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

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

.nav__toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 1px;
  transition: all var(--transition);
}

/* ===========================
   Language Toggle
   =========================== */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 4px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  padding: 4px 12px;
  cursor: pointer;
  font-family: var(--font-family);
  font-size: 0.8rem;
  font-weight: 500;
  transition: all var(--transition);
}

.lang-toggle:hover {
  border-color: var(--color-text);
}

.lang-toggle__option {
  color: var(--color-text-secondary);
  transition: color var(--transition);
}

.lang-toggle__option.active {
  color: var(--color-text);
  font-weight: 600;
}

.lang-toggle__divider {
  color: var(--color-border);
  font-weight: 300;
}

/* ===========================
   Buttons
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 28px;
  font-family: var(--font-family);
  font-size: 0.9rem;
  font-weight: 500;
  border-radius: var(--radius-sm);
  border: none;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-accent);
  color: #0e1117;
}

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

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

.btn--outline:hover {
  border-color: var(--color-text);
  transform: translateY(-1px);
}

.btn--full {
  width: 100%;
}

/* ===========================
   Hero
   =========================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: var(--nav-height);
}

.hero .container {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: var(--space-xl);
  align-items: center;
}

.hero__greeting {
  font-size: 1rem;
  color: var(--color-text-secondary);
  font-weight: 400;
  margin-bottom: var(--space-xs);
}

.hero__name {
  font-size: clamp(2.5rem, 6vw, 3.75rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: var(--space-sm);
}

.hero__title {
  font-size: clamp(1.1rem, 2.5vw, 1.35rem);
  color: var(--color-text-secondary);
  font-weight: 400;
  margin-bottom: var(--space-md);
}

.hero__description {
  font-size: 1.05rem;
  color: var(--color-text-secondary);
  max-width: 520px;
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

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

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__avatar {
  width: 200px;
  height: 200px;
  border-radius: 50%;
  background: linear-gradient(135deg, #1a1f2b, #2a3040);
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  font-size: 3rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  letter-spacing: -0.03em;
  box-shadow: 0 0 40px rgba(100, 130, 170, 0.15), var(--shadow-lg);
  border: 1px solid var(--color-border);
}

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

.hero__avatar img + .hero__avatar-fallback {
  display: none;
}

.hero__avatar img[src=""] ~ .hero__avatar-fallback,
.hero__avatar img:not([src]) ~ .hero__avatar-fallback {
  display: block;
}

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

.about__text p {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-md);
  line-height: 1.75;
}

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

.about__traits {
  display: grid;
  gap: var(--space-sm);
}

.trait {
  padding: var(--space-md);
  background: rgba(26, 31, 43, 0.8);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-light);
  transition: all 0.3s ease;
}

.trait:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
  transform: translateX(6px);
}

.trait__icon {
  width: 36px;
  height: 36px;
  margin-bottom: var(--space-xs);
  color: var(--color-accent);
}

.trait__icon svg {
  width: 100%;
  height: 100%;
}

.trait h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 4px;
}

.trait p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

/* ===========================
   Expertise
   =========================== */
.expertise__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-sm);
}

.expertise__card {
  padding: var(--space-lg);
  background: rgba(26, 31, 43, 0.8);
  backdrop-filter: blur(4px);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-light);
  transition: all 0.3s ease;
}

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

.expertise__icon {
  width: 40px;
  height: 40px;
  margin-bottom: var(--space-sm);
  color: var(--color-accent);
}

.expertise__icon svg {
  width: 100%;
  height: 100%;
}

.expertise__card h3 {
  font-size: 1.05rem;
  font-weight: 600;
  margin-bottom: var(--space-xs);
}

.expertise__card p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.6;
}

/* ===========================
   Timeline / Experience
   =========================== */
.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: var(--color-border);
}

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

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

.timeline__marker {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 15px;
  height: 15px;
  border-radius: 50%;
  background: var(--color-bg);
  border: 2px solid rgba(120, 150, 180, 0.5);
  z-index: 1;
  transition: all 0.3s ease;
  box-shadow: 0 0 8px rgba(100, 130, 170, 0.2);
}

.timeline__item:first-child .timeline__marker {
  background: rgba(120, 150, 180, 0.6);
  border-color: rgba(120, 150, 180, 0.8);
  box-shadow: 0 0 12px rgba(100, 130, 170, 0.4);
}

.timeline__content {
  background: rgba(26, 31, 43, 0.8);
  backdrop-filter: blur(4px);
  padding: var(--space-md) var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-light);
  transition: all 0.3s ease;
}

.timeline__content:hover {
  box-shadow: var(--shadow-md);
  border-color: var(--color-border);
  transform: translateX(6px);
}

.timeline__content:hover + .timeline__marker,
.timeline__item:hover .timeline__marker {
  transform: scale(1.4);
  background: var(--color-accent);
}

.timeline__header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-bottom: 4px;
}

.timeline__header h3 {
  font-size: 1.05rem;
  font-weight: 600;
}

.timeline__company {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-text-secondary);
}

.timeline__date {
  display: block;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: 2px;
}

.timeline__location {
  display: block;
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-xs);
}

.timeline__content p {
  font-size: 0.9rem;
  color: var(--color-text-secondary);
  line-height: 1.65;
}

/* ===========================
   Contact
   =========================== */
.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-xl);
  align-items: start;
}

.contact__info {
  display: grid;
  gap: var(--space-md);
}

.contact__item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-sm);
  transition: transform 0.3s ease;
}

.contact__item:hover {
  transform: translateX(6px);
}

.contact__icon {
  width: 40px;
  height: 40px;
  min-width: 40px;
  padding: 8px;
  background: rgba(26, 31, 43, 0.8);
  border-radius: var(--radius-sm);
  border: 1px solid var(--color-border-light);
  color: var(--color-accent);
  transition: all 0.3s ease;
}

.contact__item:hover .contact__icon {
  box-shadow: var(--shadow-sm);
  border-color: var(--color-border);
}

.contact__icon svg {
  width: 100%;
  height: 100%;
}

.contact__item h3 {
  font-size: 0.9rem;
  font-weight: 600;
  margin-bottom: 2px;
}

.contact__item p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

/* ===========================
   Form
   =========================== */
.contact__form {
  display: grid;
  gap: var(--space-sm);
  background: rgba(26, 31, 43, 0.8);
  backdrop-filter: blur(4px);
  padding: var(--space-lg);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border-light);
}

.form__group {
  display: grid;
  gap: 6px;
}

.form__group label {
  font-size: 0.85rem;
  font-weight: 500;
}

.form__group input,
.form__group textarea {
  width: 100%;
  padding: 10px 14px;
  font-family: var(--font-family);
  font-size: 0.9rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-surface);
  color: var(--color-text);
  transition: all 0.3s ease;
  outline: none;
}

.form__group input:focus,
.form__group textarea:focus {
  border-color: rgba(120, 150, 180, 0.5);
  box-shadow: 0 0 0 3px rgba(100, 130, 170, 0.15);
}

.form__group textarea {
  resize: vertical;
  min-height: 100px;
}

.form__group input::placeholder,
.form__group textarea::placeholder {
  color: var(--color-text-secondary);
  opacity: 0.5;
}

/* ===========================
   Footer
   =========================== */
.footer {
  padding: var(--space-lg) 0;
  border-top: 1px solid var(--color-border-light);
  position: relative;
  z-index: 1;
}

.footer__content {
  text-align: center;
}

.footer__content p {
  font-size: 0.85rem;
  color: var(--color-text-secondary);
}

/* ===========================
   Scroll Animations
   =========================== */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  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.visible {
  opacity: 1;
  transform: translateY(0);
}

.slide-left {
  opacity: 0;
  transform: translateX(-40px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.slide-left.visible {
  opacity: 1;
  transform: translateX(0);
}

.slide-right {
  opacity: 0;
  transform: translateX(40px);
  transition: opacity 0.6s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.6s cubic-bezier(0.16, 1, 0.3, 1);
}

.slide-right.visible {
  opacity: 1;
  transform: translateX(0);
}

.scale-in {
  opacity: 0;
  transform: scale(0.9);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}

.scale-in.visible {
  opacity: 1;
  transform: scale(1);
}

.stagger-1 { transition-delay: 0.05s; }
.stagger-2 { transition-delay: 0.1s; }
.stagger-3 { transition-delay: 0.15s; }
.stagger-4 { transition-delay: 0.2s; }
.stagger-5 { transition-delay: 0.25s; }
.stagger-6 { transition-delay: 0.3s; }

/* ===========================
   Parallax helper
   =========================== */
.parallax-slow {
  will-change: transform;
}

/* ===========================
   Responsive
   =========================== */
@media (max-width: 968px) {
  .hero .container {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero__description {
    margin-left: auto;
    margin-right: auto;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__visual {
    order: -1;
  }

  .hero__avatar {
    width: 140px;
    height: 140px;
    font-size: 2.25rem;
  }

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

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

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

@media (max-width: 768px) {
  :root {
    --space-2xl: 3rem;
  }

  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(14, 17, 23, 0.95);
    backdrop-filter: blur(12px);
    flex-direction: column;
    justify-content: center;
    gap: var(--space-lg);
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
  }

  .nav__menu.open {
    opacity: 1;
    pointer-events: auto;
  }

  .nav__link {
    font-size: 1.25rem;
  }

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

  .nav__toggle.active span:nth-child(2) {
    opacity: 0;
  }

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

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

  .timeline {
    padding-left: 24px;
  }

  .timeline__marker {
    left: -24px;
    width: 12px;
    height: 12px;
  }

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

  .timeline__content {
    padding: var(--space-sm) var(--space-md);
  }
}

@media (max-width: 480px) {
  .hero__actions {
    flex-direction: column;
    width: 100%;
  }

  .hero__actions .btn {
    width: 100%;
  }
}