* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
html {
  scroll-behavior: smooth;
}

body {
  font-family: "Segoe UI", sans-serif;
  background-color: var(--bg);
  color: var(--text);
  scroll-behavior: smooth;
  transition: background 0.3s, color 0.3s;
}

/* === Темы === */
:root {
  --bg: #f4f4f4;
  --text: #111;
  --accent: #4c8bf5;
  --card-bg: #ffffff;
}

body.dark {
  --bg: #111;
  --text: #f4f4f4;
  --accent: #ffcc00;
  --card-bg: #1a1a1a;
}

/* === Header === */
header {
  position: fixed;
  width: 100%;
  top: 0;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(10px);
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 25px;
  z-index: 1000;
}

body.dark header {
  background: rgba(0, 0, 0, 0.7);
}

.logo {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
}

nav {
  display: flex;
  gap: 20px;
}

nav a {
  text-decoration: none;
  color: var(--text);
  font-weight: 500;
  transition: color 0.3s;
}

nav a:hover {
  color: var(--accent);
}

#theme-toggle {
  background: none;
  border: none;
  font-size: 22px;
  cursor: pointer;
  color: var(--text);
}

.hamburger {
  display: none;
  flex-direction: column;
  cursor: pointer;
  gap: 5px;
}

.hamburger span {
  width: 25px;
  height: 3px;
  background: var(--text);
  transition: 0.3s;
}

/* === Разделы === */
.section {
  min-height: 100vh;
  padding: 120px 20px 60px;
  text-align: center;
}

.section h2 {
  font-size: 28px;
  margin-bottom: 15px;
}

.avatar {
  width: 220px;
  height: 220px;
  border-radius: 50%;
  margin: 15px 0;
  border: 3px solid var(--accent);
}

button, .contact-btn {
  background: var(--accent);
  color: white;
  border: none;
  border-radius: 8px;
  padding: 10px 20px;
  margin: 10px;
  cursor: pointer;
  transition: transform 0.2s, background 0.3s;
}

button:hover, .contact-btn:hover {
  transform: scale(1.05);
}

.project-list {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 20px;
  margin: 20px 0;
}

.project-card {
  background: var(--card-bg);
  color: var(--text);
  padding: 15px;
  border-radius: 10px;
  min-width: 160px;
  box-shadow: 0 2px 6px rgba(0,0,0,0.15);
  transition: transform 0.3s;
}

.project-card:hover {
  transform: translateY(-5px);
}

.project-card img {
  width: 100%;
  border-radius: 8px;
  margin-bottom: 10px;
}

footer {
  text-align: center;
  padding: 20px;
  font-size: 14px;
}

/* === Кнопка "наверх" === */
.scroll-top {
  position: fixed;
  bottom: 30px;
  right: 25px;
  display: none;
  background: var(--accent);
  color: white;
  font-size: 22px;
  border: none;
  border-radius: 50%;
  width: 45px;
  height: 45px;
  cursor: pointer;
  transition: opacity 0.3s, transform 0.2s;
}

.scroll-top:hover {
  transform: scale(1.1);
}

/* === Мобильная адаптация === */
@media (max-width: 768px) {
  nav {
    display: none;
    flex-direction: column;
    position: absolute;
    top: 70px;
    right: 20px;
    background: var(--bg);
    padding: 15px;
    border-radius: 10px;
  }

  nav.open {
    display: flex;
  }

  .hamburger {
    display: flex;
  }
}