/* === Custom Properties === */
:root {
  --color-bg: #F9F9F9;
  --color-surface: #FFFFFF;
  --color-text: #111111;
  --color-text-muted: #666666;
  --color-accent: #2B2D42;
  --color-border: #E5E5E5;
  --font: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --max-width: 1100px;
  --section-padding: 96px 0;
  --nav-height: 64px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

ul {
  list-style: none;
}

/* === Container === */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* === Navigation === */
.nav {
  position: sticky;
  top: 0;
  background: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  z-index: 100;
}

.nav__container {
  display: flex;
  align-items: center;
  gap: 32px;
  height: var(--nav-height);
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.nav__logo {
  font-weight: 600;
  font-size: 16px;
  white-space: nowrap;
}

.nav__links {
  display: flex;
  gap: 24px;
  margin-left: auto;
}

.nav__links a {
  font-size: 14px;
  color: var(--color-text-muted);
  transition: color 0.2s;
}

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

.nav__lang {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  color: var(--color-text-muted);
}

.nav__lang-sep {
  color: var(--color-border);
}

.lang-btn {
  background: none;
  border: none;
  cursor: pointer;
  font-size: 13px;
  color: var(--color-text-muted);
  font-family: var(--font);
  padding: 2px 4px;
  transition: color 0.2s;
}

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

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

.nav__burger {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 20px;
  color: var(--color-text);
  padding: 4px;
}

/* === Buttons === */
.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: 6px;
  font-size: 15px;
  font-weight: 500;
  font-family: var(--font);
  transition: background-color 0.2s, color 0.2s, opacity 0.2s;
  cursor: pointer;
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-surface);
  border: 1.5px solid var(--color-accent);
}

.btn--primary:hover {
  opacity: 0.85;
}

.btn--secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}

.btn--secondary:hover {
  background: var(--color-accent);
  color: var(--color-surface);
}

/* === Hero === */
.hero {
  padding: 120px 0 100px;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 56px;
  align-items: center;
}

.hero__photo {
  width: 280px;
  height: 280px;
  object-fit: cover;
  border-radius: 16px;
  border: 1px solid var(--color-border);
}

.hero__name {
  font-size: clamp(36px, 6vw, 64px);
  font-weight: 700;
  letter-spacing: -1.5px;
  line-height: 1.05;
}

.hero__role {
  font-size: 18px;
  color: var(--color-text-muted);
  margin-top: 12px;
  letter-spacing: 0.2px;
}

.hero__tagline {
  font-size: clamp(22px, 3.5vw, 32px);
  font-weight: 700;
  margin-top: 36px;
  line-height: 1.3;
  letter-spacing: -0.5px;
}

.hero__cta {
  display: flex;
  gap: 16px;
  margin-top: 44px;
  flex-wrap: wrap;
}

/* === About === */
.about {
  padding: var(--section-padding);
  background: var(--color-surface);
}

.about__content {
  display: grid;
  grid-template-columns: 1fr minmax(200px, 260px);
  gap: 64px;
  align-items: start;
}

.about__text h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 24px;
  letter-spacing: -0.5px;
}

.about__text p {
  color: var(--color-text-muted);
  font-size: 16px;
  line-height: 1.75;
  margin-bottom: 16px;
}

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

.about__facts {
  display: flex;
  flex-direction: column;
  gap: 28px;
  padding-top: 60px;
}

.fact {
  display: flex;
  flex-direction: column;
}

.fact__number {
  font-size: 40px;
  font-weight: 700;
  letter-spacing: -1px;
  line-height: 1;
}

.fact__label {
  font-size: 14px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.fact__label--wide {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-text);
}

.about__education {
  margin-top: 36px;
}

.about__education-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 16px;
  letter-spacing: -0.2px;
}

.about__education-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.edu-card {
  display: flex;
  flex-direction: column;
  padding: 20px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-bg);
  transition: border-color 0.2s, transform 0.2s;
}

.edu-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-3px);
}

.edu-card__title {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 10px;
  letter-spacing: -0.2px;
}

.edu-card__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
}

.edu-card__link {
  display: inline-block;
  margin-top: 16px;
  font-size: 13px;
  font-weight: 500;
  color: var(--color-accent);
}

/* === Experience === */
.experience {
  padding: var(--section-padding);
  background: var(--color-bg);
}

.experience h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 40px;
  letter-spacing: -0.5px;
}

.experience__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.exp-card {
  display: flex;
  flex-direction: column;
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-surface);
}

.exp-card--current {
  border-color: var(--color-accent);
}

.exp-card__period {
  font-size: 12px;
  color: var(--color-text-muted);
  font-family: 'Courier New', monospace;
  margin-bottom: 10px;
  letter-spacing: 0.3px;
}

.exp-card__company {
  font-size: 16px;
  font-weight: 600;
  margin-bottom: 4px;
  letter-spacing: -0.2px;
}

.exp-card__role {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-bottom: 14px;
}

.exp-card__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
}

.experience__note {
  margin-top: 28px;
  font-size: 14px;
  color: var(--color-text-muted);
}

/* === AI Work === */
.ai-work {
  padding: var(--section-padding);
  background: var(--color-bg);
}

.ai-work h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.5px;
}

.ai-work__lead {
  max-width: 720px;
  font-size: 16px;
  line-height: 1.75;
  color: var(--color-text-muted);
  margin-bottom: 40px;
}

.ai-work__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.ai-card {
  display: flex;
  flex-direction: column;
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-surface);
}

.ai-card__title {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.2px;
}

.ai-card__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
}

/* === Projects === */
.projects {
  padding: var(--section-padding);
  background: var(--color-bg);
}

.projects h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 40px;
  letter-spacing: -0.5px;
}

.projects__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.project-card {
  display: flex;
  flex-direction: column;
  padding: 28px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  background: var(--color-surface);
  transition: border-color 0.2s, transform 0.2s;
}

.project-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-3px);
}

.project-card__domain {
  font-size: 12px;
  color: var(--color-text-muted);
  font-family: 'Courier New', monospace;
  margin-bottom: 14px;
  letter-spacing: 0.3px;
}

.project-card__title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.2px;
}

.project-card__desc {
  font-size: 14px;
  color: var(--color-text-muted);
  line-height: 1.65;
  flex: 1;
}

.project-card__link {
  display: inline-block;
  margin-top: 20px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-accent);
}

/* === Contact === */
.contact {
  padding: var(--section-padding);
  background: var(--color-surface);
}

.contact h2 {
  font-size: 28px;
  font-weight: 700;
  margin-bottom: 36px;
  letter-spacing: -0.5px;
}

.contact__links {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.contact__link {
  display: flex;
  align-items: center;
  gap: 24px;
  font-size: 16px;
  transition: opacity 0.2s;
  width: fit-content;
}

.contact__link:hover {
  opacity: 0.65;
}

.contact__label {
  font-weight: 600;
  min-width: 84px;
}

.contact__value {
  color: var(--color-text-muted);
}

.contact__form {
  display: flex;
  flex-direction: column;
  gap: 18px;
  max-width: 460px;
  margin-top: 40px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.form-group label {
  font-size: 14px;
  font-weight: 500;
}

.form-group input {
  font-family: var(--font);
  font-size: 15px;
  padding: 11px 14px;
  border: 1px solid var(--color-border);
  border-radius: 6px;
  background: var(--color-bg);
  color: var(--color-text);
  transition: border-color 0.2s;
}

.form-group input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.contact__form .btn {
  align-self: flex-start;
}

.form-success {
  margin-top: 40px;
  font-size: 18px;
  font-weight: 600;
  color: var(--color-text);
}

/* === Footer === */
.footer {
  padding: 28px 0;
  border-top: 1px solid var(--color-border);
  background: var(--color-bg);
}

.footer .container {
  display: flex;
  justify-content: center;
}

.footer span {
  font-size: 13px;
  color: var(--color-text-muted);
}

/* === Mobile === */
@media (max-width: 768px) {
  .nav__links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    padding: 16px 24px;
    flex-direction: column;
    gap: 16px;
  }

  .nav__links.open {
    display: flex;
  }

  .nav__links a {
    font-size: 16px;
  }

  .nav__burger {
    display: block;
  }

  .nav__lang {
    margin-left: auto;
  }

  .nav__container {
    position: relative;
  }

  .hero {
    padding: 80px 0 64px;
  }

  .hero__inner {
    grid-template-columns: 1fr;
    gap: 32px;
    text-align: center;
  }

  .hero__photo {
    order: -1;
    justify-self: center;
    width: 200px;
    height: 200px;
  }

  .hero__cta {
    justify-content: center;
  }

  .about__content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about__facts {
    flex-direction: row;
    flex-wrap: wrap;
    padding-top: 0;
    gap: 24px;
  }

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

  .fact {
    min-width: 100px;
  }

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

  .ai-work__grid {
    grid-template-columns: 1fr;
  }

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

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

  .btn {
    text-align: center;
  }

  .contact__link {
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
  }

  .contact__label {
    min-width: unset;
  }
}