/* =========================
   ТЕМА (CSS-переменные)
   ========================= */
:root{
  --bg:#ffffff;
  --text:#111111;
  --accent:#0095ff;
  --accent-hover:#0077cc;
  --border:#d0d0d0;
  --muted:#666666;

  --card-bg:#ffffff;
  --card-border:rgba(0,0,0,.08);
  --shadow:0 6px 18px rgba(0,0,0,.08);
}

body.dark-mode{
  --bg:#111214;
  --text:#f2f2f2;
  --accent:#66b3ff;
  --accent-hover:#88ccff;
  --border:#4c4c4c;
  --muted:#aaaaaa;

  --card-bg:#17191f;
  --card-border:rgba(255,255,255,.06);
  --shadow:0 8px 20px rgba(0,0,0,.35);
}

/* =========================
   БАЗА
   ========================= */
*{ box-sizing:border-box; }
html{ scroll-behavior:smooth; }
body{
  margin:0;
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Ubuntu,"Helvetica Neue",Arial,"Noto Sans",sans-serif;
  background:var(--bg);
  color:var(--text);
  transition:background-color .25s ease,color .25s ease;
}
a{ color:var(--accent); text-decoration:none; }
a:hover{ color:var(--accent-hover); }

/* =========================
   ШАПКА (липкая навигация)
   ========================= */
header{
  position:sticky;
  top:0;
  z-index:100;
  background:var(--bg);
  border-bottom:1px solid var(--border);
  backdrop-filter:saturate(1.1) blur(6px);
}
.navbar{
  max-width:1100px;
  margin:0 auto;
  padding:10px 16px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:16px;
}
.navbar h1{
  margin:0;
  font-size:26px;
  font-weight:800;
}

/* Меню */
.nav-links{
  display:flex;
  flex-wrap:wrap;
  gap:24px;
  list-style:none;
  margin:0;
  padding:0;
}
.nav-links a{
  color:var(--accent);
  font-weight:700;
  font-size:1.05rem;
  transition:color .2s ease, transform .15s ease;
}
.nav-links a:hover{ transform:translateY(-1px); }
.nav-links a.active{
  color:#ff7a00;
  text-decoration:underline;
}

/* Кнопка темы */
#theme-toggle{
  margin-left:8px;
  font-size:1.3rem;
  padding:8px 12px;
  border-radius:12px;
  background:var(--bg);
  color:var(--text);
  border:1.5px solid var(--text);
  cursor:pointer;
  transition:background-color .2s ease, transform .1s ease;
}
#theme-toggle:active{ transform:scale(.98); }

/* =========================
   КОНТЕНТ
   ========================= */
main{
  text-align:center;
  padding:40px 20px;
}
section{
  margin:60px auto;
  max-width:1100px;
  scroll-margin-top:80px; /* якоря под липкой шапкой */
}
h2{ margin-bottom:20px; }

/* Герой (опционально можно подправить) */
.hero p{ color:var(--muted); }

/* Фото в «Обо мне» */
.about-photo{
  max-width:200px;
  width:100%;
  border-radius:12px;
  margin:20px 0;
  box-shadow:0 4px 12px rgba(0,0,0,.2);
  transition:transform .3s ease;
}
.about-photo:hover{ transform:scale(1.05); }

/* =========================
   АНИМАЦИЯ ПОЯВЛЕНИЯ
   ========================= */
.fade-in{
  opacity:0;
  transform:translateY(20px);
  transition:opacity .6s ease-out, transform .6s ease-out;
}
.fade-in.visible{
  opacity:1;
  transform:none;
}

/* =========================
   ПРОЕКТЫ (карточки)
   ========================= */
.projects-grid{
  display:grid;
  grid-template-columns:repeat(auto-fit, minmax(260px, 1fr));
  gap:20px;
  text-align:left;
}
.card{
  background:var(--card-bg);
  border:1px solid var(--card-border);
  border-radius:16px;
  box-shadow:var(--shadow);
  overflow:hidden;
  transition:transform .15s ease, box-shadow .2s ease, border-color .2s ease;
}
.card:hover{
  transform:translateY(-2px);
  border-color:var(--accent);
  box-shadow:0 10px 24px rgba(0,0,0,.12);
}
.card-body{ padding:18px; }
.card-title{ margin:0 0 8px; font-size:1.1rem; }
.card-text{ margin:0; color:var(--muted); line-height:1.5; }
.card-actions{
  display:flex;
  gap:12px;
  padding:0 18px 18px 18px;
}
.btn{
  display:inline-block;
  padding:10px 14px;
  border-radius:12px;
  border:1px solid var(--border);
  color:var(--text);
  transition:background-color .2s ease, transform .1s ease, border-color .2s ease;
}
.btn:hover{ transform:translateY(-1px); border-color:var(--accent); }
.btn.primary{
  background:var(--accent);
  color:#fff;
  border-color:transparent;
}
.btn.primary:hover{ background:var(--accent-hover); }

/* =========================
   КНОПКА «НАВЕРХ»
   ========================= */
#toTopBtn{
  position:fixed;
  right:20px;
  bottom:20px;
  width:44px;
  height:44px;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  font-size:22px;
  border:none;
  border-radius:999px;
  cursor:pointer;
  background:var(--accent);
  color:#fff;
  box-shadow:0 8px 20px rgba(0,0,0,.2);
  opacity:0;
  transform:translateY(10px);
  pointer-events:none;
  transition:opacity .2s, transform .2s, background .2s;
}
#toTopBtn.show{
  opacity:1;
  transform:translateY(0);
  pointer-events:auto;
}
#toTopBtn:hover{ background:var(--accent-hover); }

/* =========================
   ПОЛОСА ПРОГРЕССА ПРОКРУТКИ
   ========================= */
#scrollProgress{
  position:fixed;
  top:0;
  left:0;
  height:4px;
  width:0;               /* JS меняет ширину 0→100% */
  background:linear-gradient(90deg,#00d2ff,#3a7bd5);
  z-index:9999;
  transition:width .1s linear;
}

/* =========================
   АДАПТИВ
   ========================= */
@media (max-width:700px){
  .navbar{ gap:10px; }
  .navbar h1{ font-size:22px; }
  .nav-links{ gap:14px; }
  .nav-links a{ font-size:.98rem; }
  #theme-toggle{ font-size:1.1rem; padding:6px 10px; }
}