/* ===== RESET & BASE ===== */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: Arial, Helvetica, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: #1F2937;
  background-color: #F9FAFB;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

img {
  max-width: 100%;
  display: block;
}

/* ===== ROOT VARIABLES ===== */
:root {
  --color-primary: #4F46E5;
  --color-primary-hover: #4338CA;
  --color-bg: #F9FAFB;
  --color-white: #FFFFFF;
  --color-text: #1F2937;
  --color-text-light: #6B7280;
  --color-border: #E5E7EB;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.06);
  --radius: 12px;
  --transition: 0.3s ease;
}

/* ===== CONTAINER ===== */
.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background var(--transition), transform var(--transition), box-shadow var(--transition);
}

.btn:active {
  transform: scale(0.97);
}

.btn--primary {
  background: var(--color-primary);
  color: var(--color-white);
}

.btn--primary:hover {
  background: var(--color-primary-hover);
  box-shadow: 0 6px 20px rgba(79, 70, 229, 0.35);
}

/* ===== SECTION TITLE ===== */
.section-title {
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 48px;
  position: relative;
}

.section-title::after {
  content: '';
  display: block;
  width: 60px;
  height: 4px;
  background: var(--color-primary);
  border-radius: 2px;
  margin: 12px auto 0;
}

/* ===== HEADER ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  background: var(--color-white);
  border-bottom: 1px solid var(--color-border);
  z-index: 1000;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.04);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-top: 16px;
  padding-bottom: 16px;
}

.header__logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 700;
  color: var(--color-primary);
}

.header__nav-list {
  display: flex;
  gap: 32px;
}

.header__nav-link {
  font-weight: 500;
  color: var(--color-text);
  transition: color var(--transition);
  position: relative;
}

.header__nav-link::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -4px;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition);
}

.header__nav-link:hover {
  color: var(--color-primary);
}

.header__nav-link:hover::after {
  width: 100%;
}

/* Burger */
.header__burger {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  border-radius: 6px;
  transition: background var(--transition);
}

.header__burger:hover {
  background: rgba(79, 70, 229, 0.06);
}

.header__burger span {
  display: block;
  width: 26px;
  height: 3px;
  background: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.header__burger.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.header__burger.active span:nth-child(2) {
  opacity: 0;
}

.header__burger.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ===== HERO ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  text-align: center;
  background: linear-gradient(135deg, #EEF2FF 0%, #E0E7FF 50%, #C7D2FE 100%);
  padding-top: 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79, 70, 229, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero::after {
  content: '';
  position: absolute;
  bottom: -30%;
  left: -15%;
  width: 500px;
  height: 500px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(79, 70, 229, 0.05) 0%, transparent 70%);
  pointer-events: none;
}

.hero__inner {
  position: relative;
  z-index: 1;
}

.hero__title {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.15;
  margin-bottom: 20px;
  color: var(--color-text);
  animation: fadeInUp 0.8s ease-out;
}

.hero__subtitle {
  font-size: 20px;
  color: var(--color-text-light);
  max-width: 580px;
  margin: 0 auto 36px;
  animation: fadeInUp 0.8s ease-out 0.15s both;
}

.hero .btn {
  animation: fadeInUp 0.8s ease-out 0.3s both;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* ===== SERVICES ===== */
.services {
  padding: 96px 0;
  background: var(--color-white);
}

.services__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 32px;
}

.service-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 32px 24px;
  text-align: center;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: var(--color-primary);
  transform: scaleX(0);
  transition: transform var(--transition);
  transform-origin: left;
}

.service-card:hover {
  transform: translateY(-8px) scale(1.03);
  box-shadow: 0 16px 40px rgba(79, 70, 229, 0.15);
  border-color: var(--color-primary);
}

.service-card:hover::before {
  transform: scaleX(1);
}

.service-card__icon {
  margin-bottom: 20px;
  display: flex;
  justify-content: center;
  transition: transform var(--transition);
}

.service-card:hover .service-card__icon {
  transform: scale(1.1);
}

.service-card__icon svg rect {
  transition: fill var(--transition);
}

.service-card:hover .service-card__icon svg rect {
  fill: #E0E7FF;
}

.service-card__icon svg path,
.service-card__icon svg circle {
  transition: stroke var(--transition);
}

.service-card:hover .service-card__icon svg path,
.service-card:hover .service-card__icon svg circle {
  stroke: #4338CA;
}

.service-card__title {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  transition: color var(--transition);
}

.service-card:hover .service-card__title {
  color: var(--color-primary);
}

.service-card__desc {
  font-size: 15px;
  color: var(--color-text-light);
  line-height: 1.6;
}

/* ===== CONTACTS ===== */
.contacts {
  padding: 96px 0;
  background: var(--color-bg);
}

.contacts__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: start;
}

/* Form */
.contacts__form {
  background: var(--color-white);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 40px;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition);
}

.contacts__form:focus-within {
  box-shadow: 0 8px 32px rgba(79, 70, 229, 0.1);
}

.form-group {
  margin-bottom: 20px;
}

.form-label {
  display: block;
  font-weight: 600;
  margin-bottom: 6px;
  font-size: 14px;
  color: var(--color-text);
  transition: color var(--transition);
}

.form-group:focus-within .form-label {
  color: var(--color-primary);
}

.form-input {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: 8px;
  font-size: 15px;
  font-family: inherit;
  color: var(--color-text);
  background: var(--color-white);
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}

.form-input::placeholder {
  color: #9CA3AF;
  opacity: 1;
  transition: opacity var(--transition);
}

.form-input:focus::placeholder {
  opacity: 0.5;
}

.form-input:hover {
  border-color: #C7D2FE;
}

.form-input:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.15);
  background: var(--color-white);
}

.form-textarea {
  resize: vertical;
  min-height: 120px;
}

/* Contact info */
.contacts__info {
  display: flex;
  flex-direction: column;
  gap: 24px;
  padding: 40px 0;
}

.contacts__info-item {
  display: flex;
  align-items: center;
  gap: 14px;
  font-size: 16px;
  color: var(--color-text);
  padding: 16px 20px;
  border-radius: var(--radius);
  background: var(--color-white);
  border: 1px solid var(--color-border);
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}

.contacts__info-item:hover {
  transform: translateX(6px);
  box-shadow: 0 4px 16px rgba(79, 70, 229, 0.08);
  border-color: var(--color-primary);
}

.contacts__info-item svg {
  flex-shrink: 0;
  transition: transform var(--transition);
}

.contacts__info-item:hover svg {
  transform: scale(1.15);
}

.contacts__info-item svg path,
.contacts__info-item svg circle {
  transition: stroke var(--transition);
}

.contacts__info-item:hover svg path,
.contacts__info-item:hover svg circle {
  stroke: #4338CA;
}

/* ===== FOOTER ===== */
.footer {
  background: #1F2937;
  color: #D1D5DB;
  padding: 40px 0;
}

.footer__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer__copy {
  font-size: 14px;
  color: #9CA3AF;
}

.footer__links {
  display: flex;
  gap: 24px;
}

.footer__link {
  font-size: 14px;
  color: #9CA3AF;
  transition: color var(--transition);
}

.footer__link:hover {
  color: var(--color-white);
}

.footer__socials {
  display: flex;
  gap: 12px;
}

.footer__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.06);
  transition: background var(--transition), transform var(--transition);
}

.footer__social-link:hover {
  background: rgba(255, 255, 255, 0.12);
  transform: translateY(-2px);
}

.footer__social-link svg path {
  transition: fill var(--transition);
}

.footer__social-link:hover svg path {
  fill: #FFFFFF;
}

/* ===== ADAPTIVE (MEDIA QUERIES) ===== */
@media (max-width: 768px) {
  .header__nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-white);
    display: flex;
    align-items: center;
    justify-content: center;
    transform: translateX(100%);
    transition: transform var(--transition);
    z-index: 5;
    visibility: hidden;
    transition: transform var(--transition), visibility var(--transition);
  }

  .header__nav.open {
    transform: translateX(0);
    visibility: visible;
  }

  .header__nav-list {
    flex-direction: column;
    align-items: center;
    gap: 40px;
  }

  .header__nav-link {
    font-size: 22px;
  }

  .header__burger {
    display: flex;
    z-index: 10;
  }

  .hero__title {
    font-size: 32px;
  }

  .hero__subtitle {
    font-size: 17px;
  }

  .section-title {
    font-size: 26px;
    margin-bottom: 36px;
  }

  .contacts__inner {
    grid-template-columns: 1fr;
    gap: 32px;
  }

  .contacts__form {
    padding: 24px;
  }

  .footer__inner {
    flex-direction: column;
    text-align: center;
  }
}

@media (max-width: 600px) {
  .footer__inner {
    flex-direction: column;
    text-align: center;
    gap: 20px;
  }

  .footer__links {
    flex-direction: column;
    gap: 12px;
  }
}

@media (max-width: 480px) {
  .hero__title {
    font-size: 26px;
  }

  .hero__subtitle {
    font-size: 15px;
  }

  .services__grid {
    grid-template-columns: 1fr;
  }

  .service-card {
    padding: 28px 20px;
  }

  .service-card:hover {
    transform: translateY(-4px) scale(1.02);
  }

  .service-card__title {
    font-size: 18px;
  }

  .service-card__desc {
    font-size: 14px;
  }

  .contacts__form {
    padding: 20px;
  }

  .contacts__form .btn {
    width: 100%;
  }

  .contacts__info-item {
    padding: 14px 16px;
    font-size: 14px;
  }
}