:root {
  --color-bg: #fff;
  --color-text: #222;
  --color-border: #ccc;
  --color-accent: #05b;
  --color-accent-contrast: #fff;
  --color-section-bg: #eaeaea;
  --color-footer-bg: #eee;
  --shadow: 0 4px 6px rgba(0 0 0 / 10%);
  --radius: 0.5rem;
  --transition: all 0.3s ease;
}

/* Автоматическая тёмная тема при системных настройках */
@media (prefers-color-scheme: dark) {
  :root:not(.light-theme) {
    --color-bg: #121212;
    --color-text: #f5f5f5;
    --color-accent: #39f;
    --color-accent-contrast: #000;
    --color-section-bg: #262626;
    --color-footer-bg: #1a1a1a;
    --color-border: #444;
  }
}

/* Класс для ручного переключения темы (перезаписывает системные настройки) */
:root.dark-theme,
body.dark-theme {
  --color-bg: #121212;
  --color-text: #f5f5f5;
  --color-accent: #39f;
  --color-accent-contrast: #000;
  --color-section-bg: #262626;
  --color-footer-bg: #1a1a1a;
  --color-border: #444;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: system-ui, sans-serif;
  line-height: 1.6;
  background: var(--color-bg);
  color: var(--color-text);
  transition: var(--transition);
}

.skip-link {
  position: absolute;
  left: -999px;
}

.skip-link:focus {
  left: 1rem;
  top: 1rem;
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  padding: 0.5rem;
  border-radius: var(--radius);
}

header {
  background: linear-gradient(90deg, var(--color-accent) 60%, #2571c3 100%);
  color: var(--color-accent-contrast);
  padding: 1.5rem 0 1rem;
  box-shadow: var(--shadow);
}

.header-content {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 1.5rem;
  max-width: 1200px;
  margin: 0 auto;
}

@media (width >= 601px) {
  .header-content {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.header-profile {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.avatar {
  width: 64px;
  height: 64px;
  border-radius: 50%;
  object-fit: cover;
  box-shadow: 0 2px 8px rgba(0 0 0 / 12%);
  border: 2px solid var(--color-accent-contrast);
  background: var(--color-bg);
  transition: var(--transition);
  cursor: pointer;
}

.header-profile h1 {
  font-size: 1.5rem;
  margin: 0;
  letter-spacing: 0.02em;
  font-weight: 700;
}

.nav-list {
  list-style: none;
  display: flex;
  gap: 1.5rem;
  padding: 0;
  margin: 0;
}

.nav-list a {
  color: var(--color-accent-contrast);
  text-decoration: none;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius);
  transition: all 0.2s;
}

.nav-list a:hover,
.nav-list a:focus {
  background: rgb(255 255 255 / 15%);
  color: var(--color-accent-contrast);
  text-decoration: none;
}

#theme-toggle {
  background: rgb(0 0 0 / 10%);
  border: 2px solid var(--color-accent-contrast);
  color: var(--color-accent-contrast);
  padding: 0.2rem 0.7rem;
  border-radius: var(--radius);
  font-size: 1.4rem;
  cursor: pointer;
  margin-left: 1rem;
  transition: var(--transition);
}

#theme-toggle:hover,
#theme-toggle:focus {
  background: var(--color-accent-contrast);
  color: var(--color-accent);
}

.content-wrapper {
  padding-left: 8px;
  padding-right: 8px;
}

@media (width >= 601px) {
  .content-wrapper {
    padding-left: 24px;
    padding-right: 24px;
  }
}

@media (width >= 1025px) {
  .content-wrapper {
    padding-left: 40px;
    padding-right: 40px;
  }
}

.section {
  padding: 2rem 1rem;
  max-width: 1000px;
  margin: 1rem auto;
  background: var(--color-section-bg);
  border-radius: var(--radius);
  transition: var(--transition);
}

.projects-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

@media (width >= 601px) {
  .projects-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (width >= 1025px) {
  .projects-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.project-card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1rem;
  background: var(--color-bg);
  box-shadow: var(--shadow);
  transition: var(--transition);
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.project-card img,
.project-card picture {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius);
  max-width: 100%;
  aspect-ratio: 16/10;
  object-fit: cover;
}

.project-card:hover {
  transform: translateY(-4px);
}

.contact-form {
  display: grid;
  gap: 0.5rem;
}

.contact-form input,
.contact-form textarea,
.contact-form button {
  font: inherit;
  padding: 0.5rem;
  border-radius: var(--radius);
  border: 1px solid var(--color-border);
  transition: var(--transition);
  background: var(--color-bg);
  box-shadow: var(--shadow);
}

.contact-form button {
  background: var(--color-accent);
  color: var(--color-accent-contrast);
  border: none;
  cursor: pointer;
  box-shadow: var(--shadow);
}

.contact-form button:hover,
.contact-form button:focus {
  opacity: 0.9;
  transform: translateY(-2px);
}

footer {
  background: var(--color-footer-bg);
  padding: 1rem;
  text-align: center;
  transition: var(--transition);
}