/* ==============================================
   FIZMAT100.RU — НЕЙРО-АБСОЛЮТ ДИЗАЙН
   ============================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:opsz,wght@14..32,400;14..32,500;14..32,600;14..32,700&family=Merriweather:wght@400;700&display=swap');

/* Цветовая модель (HSB) */
:root {
  --primary-h: 210; --primary-s: 75%; --primary-l: 15%; /* Глубокий синий */
  --accent-h: 30;  --accent-s: 100%; --accent-l: 52%;  /* Энергичный оранжевый */
  
  --primary: hsl(var(--primary-h), var(--primary-s), var(--primary-l));
  --primary-light: hsl(var(--primary-h), var(--primary-s), 25%);
  --accent: hsl(var(--accent-h), var(--accent-s), var(--accent-l));
  --accent-glow: hsl(var(--accent-h), var(--accent-s), 65%);
  
  --bg: #ffffff;
  --bg-secondary: #f8f9fa;
  --text: #1a1a1a;
  --text-secondary: #5a6c7d;
  --border: #e9ecef;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.07), 0 2px 4px -2px rgba(0,0,0,0.05);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.08), 0 4px 6px -4px rgba(0,0,0,0.04);
  --radius: 16px;
  --transition: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-serif: 'Merriweather', 'Georgia', serif;
  --max-width: 1200px;
  --nav-height: 72px;
}

[data-theme="dark"] {
  --bg: #0f1117;
  --bg-secondary: #1a1d27;
  --text: #e8e8ed;
  --text-secondary: #a0a0b0;
  --border: #2a2d3a;
  --primary: hsl(var(--primary-h), 60%, 35%);
  --primary-light: hsl(var(--primary-h), 60%, 45%);
}

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

html { font-size: 16px; scroll-behavior: smooth; }
body {
  font-family: var(--font-sans);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  transition: background var(--transition), color var(--transition);
  display: flex; flex-direction: column; min-height: 100vh;
}

/* Типографика */
h1, h2, h3 { font-family: var(--font-serif); font-weight: 700; line-height: 1.3; }
h1 { font-size: clamp(2rem, 5vw, 3.2rem); letter-spacing: -0.02em; }
h2 { font-size: clamp(1.5rem, 3vw, 2.2rem); letter-spacing: -0.01em; }
h3 { font-size: 1.3rem; font-weight: 600; }
a { color: var(--accent); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--accent-glow); }

.container { width: 100%; max-width: var(--max-width); margin: 0 auto; padding: 0 24px; }

/* Шапка (Glass-эффект) */
.header {
  background: rgba(255,255,255,0.85); backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky; top: 0; z-index: 100;
  box-shadow: var(--shadow-sm); height: var(--nav-height);
  transition: background var(--transition);
}
[data-theme="dark"] .header { background: rgba(15,17,23,0.85); }
.header .container { display: flex; align-items: center; justify-content: space-between; height: 100%; }

.logo {
  font-family: var(--font-serif); font-size: 1.6rem; font-weight: 700;
  color: var(--primary); letter-spacing: -0.01em; display: flex; align-items: center; gap: 8px;
}

[data-theme="dark"] .logo { color: #fff; }

.nav { display: flex; gap: 2rem; align-items: center; }
.nav a { color: var(--text-secondary); font-weight: 500; font-size: 0.95rem; position: relative; padding: 4px 0; }
.nav a::after {
  content: ''; position: absolute; bottom: 0; left: 0; width: 0; height: 2px;
  background: var(--accent); transition: width var(--transition);
}
.nav a:hover { color: var(--text); }
.nav a:hover::after { width: 100%; }

.theme-toggle {
  background: var(--bg-secondary); border: 1px solid var(--border); border-radius: 50%;
  width: 40px; height: 40px; display: flex; align-items: center; justify-content: center;
  cursor: pointer; font-size: 1.2rem; transition: background var(--transition), transform var(--transition);
}
.theme-toggle:hover { background: var(--primary); color: #fff; transform: rotate(15deg); }

/* Герой-секция (анатомия убеждения) */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
  color: #fff; padding: 5rem 0 4rem; text-align: center;
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; top: -50%; right: -20%; width: 600px; height: 600px;
  background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 70%);
  border-radius: 50%;
}
.hero h1 { margin-bottom: 1rem; color: #fff; }
.hero p { font-size: 1.2rem; opacity: 0.9; margin-bottom: 2rem; max-width: 600px; margin-left: auto; margin-right: auto; }
.hero-buttons { display: flex; gap: 1rem; justify-content: center; flex-wrap: wrap; }

/* Кнопки (закон Фиттса) */
.btn {
  display: inline-flex; align-items: center; gap: 0.5rem;
  padding: 0.85rem 1.8rem; border-radius: 12px; font-weight: 600;
  transition: all var(--transition); cursor: pointer; border: none; font-size: 1rem;
  box-shadow: var(--shadow-sm);
}
.btn:active { transform: scale(0.97); }
.btn-primary { background: var(--accent); color: #fff; }
.btn-primary:hover { background: var(--accent-glow); box-shadow: 0 0 20px rgba(255,140,0,0.3); transform: translateY(-2px); }
.btn-secondary { background: rgba(255,255,255,0.15); color: #fff; backdrop-filter: blur(8px); }
.btn-secondary:hover { background: rgba(255,255,255,0.25); transform: translateY(-2px); }

/* Секции */
.section { margin: 4rem 0; }
.section h2 { margin-bottom: 1.5rem; position: relative; display: inline-block; }
.section h2::after {
  content: ''; position: absolute; bottom: -6px; left: 0; width: 40px; height: 4px;
  background: var(--accent); border-radius: 2px;
}

/* Карточки (гештальт-принцип близости) */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1.8rem; }
.card {
  background: var(--bg-secondary); border-radius: var(--radius); padding: 1.8rem;
  box-shadow: var(--shadow-sm); border: 1px solid var(--border);
  transition: all var(--transition); position: relative; overflow: hidden;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); border-color: var(--accent); }
.card-tag {
  display: inline-block; background: var(--primary); color: #fff;
  padding: 0.2rem 0.8rem; border-radius: 20px; font-size: 0.8rem; margin-bottom: 1rem;
}
.card h3 a { color: var(--text); }
.card h3 a:hover { color: var(--accent); }

/* Подвал */
.footer {
  background: var(--primary); color: rgba(255,255,255,0.85); padding: 2rem 0;
  margin-top: auto; font-size: 0.9rem;
}
.footer a { color: #fff; }
.footer .container { display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }

/* Адаптивность */
@media (max-width: 768px) {
  .nav { display: none; }
  .hero { padding: 3rem 0; }
}

/* Утилиты */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }

.card-text {
    line-height: 1.4;
    margin-top: 0.8rem;
    color: var(--text-secondary);
    white-space: pre-line;
}
/* Выпадающее меню (десктоп) */
.nav-dropdown {
    position: relative;
    display: inline-block;
}
.nav-dropdown-trigger {
    cursor: pointer;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 0.95rem;
    padding: 0.5rem 0;
}
.nav-dropdown-trigger:hover {
    color: var(--text);
}
.nav-dropdown-content {
    display: none;
    position: absolute;
    top: 100%;
    right: 0;
    background: var(--bg);
    box-shadow: var(--shadow-lg);
    border-radius: 12px;
    padding: 0.5rem 0;
    z-index: 200;
    min-width: 200px;
}
.nav-dropdown:hover .nav-dropdown-content {
    display: block;
}
.nav-dropdown-content a {
    display: block;
    padding: 0.5rem 1.2rem;
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.95rem;
}
.nav-dropdown-content a:hover {
    background: var(--bg-secondary);
}