/*
  Основной файл стилей для сайта "Сантехника под ключ"
  Используются CSS‑переменные для упрощения настройки цветовой схемы и радиусов.
*/

:root {
  --color-bg: #f7f9fc;
  --color-surface: #ffffff;
  --color-primary: #0072b7; /* водный оттенок */
  --color-secondary: #009ecf; /* доп. акцент */
  --color-heat: #e6582c; /* тёплый оттенок для разделов отопления */
  --color-text: #333333;
  --color-muted: #666666;
  --color-border: #e5eaf1;
  --radius-lg: 24px;
  --radius-md: 16px;
  --shadow-sm: 0 2px 4px rgba(0,0,0,0.05);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --transition: 0.3s ease;
  --font-base: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
}

html {
  box-sizing: border-box;
  scroll-behavior: smooth;
}

*, *::before, *::after {
  box-sizing: inherit;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.6;
}

img {
  max-width: 100%;
  height: auto;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover,
a:focus {
  color: var(--color-secondary);
}

h1, h2, h3, h4, h5, h6 {
  color: var(--color-text);
  margin-top: 0;
  margin-bottom: 0.5rem;
  line-height: 1.3;
}

p {
  margin-top: 0;
  margin-bottom: 1rem;
}

ul, ol {
  padding-left: 1.2rem;
  margin-top: 0;
  margin-bottom: 1rem;
}

/* Containers */
.container {
  max-width: 1200px;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1rem;
  padding-right: 1rem;
}

/* Header */
.site-header {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow-sm);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 0.5rem;
  padding-bottom: 0.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-primary);
}

/* Navigation */
.main-nav {
  position: relative;
}

.nav-toggle {
  background: none;
  border: none;
  color: var(--color-primary);
  font-size: 1rem;
  display: none;
  cursor: pointer;
}

.nav-list {
  list-style: none;
  margin: 0;
  display: flex;
  gap: 1rem;
}

.nav-list li a {
  padding: 0.5rem 0.75rem;
  border-radius: var(--radius-md);
  display: block;
  color: var(--color-text);
  font-weight: 500;
}

.nav-list li a:hover,
.nav-list li a:focus,
.nav-list li a[aria-current="page"] {
  background-color: var(--color-primary);
  color: #ffffff;
}

/* Hero Section */
.hero {
  position: relative;
  background-color: var(--color-surface);
  padding: 4rem 0;
  overflow: hidden;
}

.hero .container {
  position: relative;
  z-index: 2;
}

.hero h1 {
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.hero p {
  max-width: 600px;
  margin-bottom: 2rem;
}

.hero .btn-primary {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-md);
  background-color: var(--color-primary);
  color: #ffffff;
  font-weight: 600;
  transition: background-color var(--transition);
}

.hero .btn-primary:hover,
.hero .btn-primary:focus {
  background-color: var(--color-secondary);
}

.hero-pattern {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 50%;
  opacity: 0.1;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero-pattern img {
  max-height: 100%;
  width: auto;
}

/* Services Overview */
.services-overview {
  padding: 3rem 0;
}

.services-overview h2 {
  text-align: center;
  margin-bottom: 2rem;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1.5rem;
}

.service-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 1.5rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition), transform var(--transition);
  text-align: left;
}

.service-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-4px);
}

.service-card .icon {
  fill: var(--color-primary);
  margin-bottom: 0.5rem;
}

.service-card h3 {
  font-size: 1.1rem;
  margin-bottom: 0.5rem;
}

.service-card p {
  font-size: 0.95rem;
  color: var(--color-muted);
}

/* Steps */
.steps {
  background-color: var(--color-surface);
  padding: 3rem 0;
}

.steps h2 {
  text-align: center;
  margin-bottom: 2rem;
}

.step-list {
  list-style: none;
  counter-reset: step;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 1.5rem;
}

.step-list li {
  position: relative;
  padding-left: 2.5rem;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding-top: 1rem;
  padding-bottom: 1rem;
  box-shadow: var(--shadow-sm);
}

.step-list li::before {
  counter-increment: step;
  content: counter(step);
  position: absolute;
  top: 1rem;
  left: 1rem;
  width: 1.5rem;
  height: 1.5rem;
  border-radius: 50%;
  background-color: var(--color-primary);
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 600;
}

/* Pricing factors */
.pricing-factors {
  padding: 3rem 0;
}

.pricing-factors h2 {
  text-align: center;
  margin-bottom: 2rem;
}

.factor-list {
  list-style: none;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

.factor-list li {
  padding: 1rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-surface);
  box-shadow: var(--shadow-sm);
}

.factor-list li strong {
  display: block;
  margin-bottom: 0.5rem;
  color: var(--color-primary);
}

/* Geo section */
.geo {
  background-color: var(--color-surface);
  padding: 3rem 0;
}

.geo h2 {
  text-align: center;
  margin-bottom: 1rem;
}

.city-list {
  list-style: none;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.75rem 1.5rem;
  max-width: 800px;
  margin: 0 auto;
}

.city-list li {
  padding: 0.25rem 0.5rem;
  border-radius: var(--radius-md);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  font-size: 0.9rem;
}

/* FAQ */
.faq-preview {
  padding: 3rem 0;
}

.faq-preview h2 {
  text-align: center;
  margin-bottom: 1.5rem;
}

.faq-item {
  margin-bottom: 1rem;
}

.faq-item h3 {
  cursor: pointer;
  font-size: 1rem;
  position: relative;
  padding-right: 2rem;
}

.faq-item p {
  margin-bottom: 0;
  font-size: 0.95rem;
  color: var(--color-muted);
}

.faq-preview .btn-secondary {
  display: inline-block;
  margin-top: 1rem;
  padding: 0.6rem 1.2rem;
  border-radius: var(--radius-md);
  background-color: var(--color-bg);
  border: 1px solid var(--color-primary);
  color: var(--color-primary);
  transition: background-color var(--transition), color var(--transition);
}

.faq-preview .btn-secondary:hover,
.faq-preview .btn-secondary:focus {
  background-color: var(--color-primary);
  color: #ffffff;
}

/* Contact form */
.contact-form-section {
  background-color: var(--color-surface);
  padding: 3rem 0;
}

.contact-form-section h2 {
  text-align: center;
  margin-bottom: 1rem;
}

.contact-form {
  max-width: 600px;
  margin: 0 auto;
  display: grid;
  gap: 1rem;
}

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

.form-group label {
  margin-bottom: 0.25rem;
  font-weight: 500;
}

.form-group input,
.form-group textarea {
  padding: 0.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  font-size: 1rem;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 2px rgba(0, 114, 183, 0.2);
  outline: none;
}

.form-group textarea {
  resize: vertical;
}

.form-group.honeypot {
  position: absolute;
  left: -10000px;
  visibility: hidden;
}

.form-group.checkbox {
  flex-direction: row;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.9rem;
}

.form-actions {
  text-align: center;
}

.btn-primary {
  padding: 0.7rem 1.5rem;
  border-radius: var(--radius-md);
  background-color: var(--color-primary);
  color: #fff;
  border: none;
  font-size: 1rem;
  cursor: pointer;
  font-weight: 600;
  transition: background-color var(--transition);
}

.btn-primary:hover,
.btn-primary:focus {
  background-color: var(--color-secondary);
}

.form-response {
  font-size: 0.9rem;
  color: var(--color-muted);
  margin-top: 0.5rem;
  min-height: 1rem;
}

/* Footer */
.site-footer {
  background-color: var(--color-bg);
  padding-top: 2rem;
  padding-bottom: 2rem;
  border-top: 1px solid var(--color-border);
}

.footer-content {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 1rem;
}

.footer-col h3 {
  margin-bottom: 0.5rem;
  font-size: 1.1rem;
  color: var(--color-text);
}

.footer-col ul {
  list-style: none;
  padding: 0;
  margin: 0;
}

.footer-col ul li + li {
  margin-top: 0.25rem;
}

.footer-col ul li a {
  color: var(--color-muted);
  font-size: 0.9rem;
  transition: color var(--transition);
}

.footer-col ul li a:hover,
.footer-col ul li a:focus {
  color: var(--color-primary);
}

.footer-bottom {
  text-align: center;
  font-size: 0.8rem;
  color: var(--color-muted);
}

/* Responsive adjustments */
@media (max-width: 768px) {
  .nav-toggle {
    display: inline-block;
  }
  .nav-list {
    flex-direction: column;
    gap: 0;
    position: absolute;
    right: 0;
    top: 100%;
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: 0.5rem 0;
    min-width: 200px;
    box-shadow: var(--shadow-md);
    display: none;
    z-index: 100;
  }
  .nav-list li a {
    padding: 0.5rem 1rem;
  }
  .nav-list.open {
    display: block;
  }
}