/* Цифровая Школа — лендинг, современный, доступный */

:root {
  --color-bg: #0f172a;
  --color-bg-card: #1e293b;
  --color-bg-elevated: #334155;
  --color-text: #f1f5f9;
  --color-text-muted: #94a3b8;
  --color-primary: #38bdf8;
  --color-primary-hover: #7dd3fc;
  --color-accent: #22c55e;
  --color-whatsapp: #25d366;
  --font: 'Manrope', -apple-system, BlinkMacSystemFont, sans-serif;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.25);
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: var(--font);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
}

.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 100;
  padding: 0.75rem 1rem;
  background: var(--color-primary);
  color: var(--color-bg);
  border-radius: var(--radius);
  font-weight: 600;
  text-decoration: none;
  transition: top var(--transition);
}
.skip-link:focus {
  top: 1rem;
}

.container {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 1.25rem;
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(15, 23, 42, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 64px;
}
.logo {
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.125rem;
}
.logo-text {
  color: var(--color-primary);
}
.nav {
  display: flex;
  align-items: center;
  gap: 1.5rem;
}
.nav a {
  color: var(--color-text-muted);
  text-decoration: none;
  font-weight: 500;
  transition: color var(--transition);
}
.nav a:hover {
  color: var(--color-text);
}
.lang-switch {
  font-size: 0.875rem;
  color: var(--color-primary);
}
.lang-switch:hover {
  color: var(--color-primary-hover);
}
.menu-toggle {
  display: none;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  padding: 0.625rem 1.25rem;
  border-radius: var(--radius);
  font-family: var(--font);
  font-weight: 600;
  font-size: 0.9375rem;
  text-decoration: none;
  border: none;
  cursor: pointer;
  transition: background var(--transition), transform 0.1s ease;
}
.btn i {
  font-size: 1.125em;
}
.btn:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.btn-primary {
  background: var(--color-primary);
  color: var(--color-bg);
}
.btn-primary:hover {
  background: var(--color-primary-hover);
}
.btn-secondary {
  background: var(--color-bg-elevated);
  color: var(--color-text);
  border: 1px solid rgba(255, 255, 255, 0.15);
}
.btn-secondary:hover {
  background: var(--color-bg-card);
  border-color: rgba(255, 255, 255, 0.25);
}
.btn-lg {
  padding: 0.875rem 1.75rem;
  font-size: 1rem;
}
.btn-whatsapp {
  background: var(--color-whatsapp);
  color: #fff;
}
.btn-whatsapp:hover {
  background: #2ee56b;
  color: #fff;
}
.cta-header {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}
/* Кнопка WhatsApp в шапке — синий фон, белый текст */
.btn-whatsapp-header {
  background: var(--color-primary);
  color: #fff;
}
.btn-whatsapp-header:hover {
  background: var(--color-primary-hover);
  color: #fff;
}
/* Кнопка «Получить демо» в шапке — контур, акцент */
.btn-demo {
  background: transparent;
  color: var(--color-primary);
  border: 2px solid var(--color-primary);
}
.btn-demo:hover {
  background: var(--color-primary);
  color: var(--color-bg);
}

/* Hero */
.hero {
  padding: 4rem 0 5rem;
  text-align: center;
}
.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
  padding: 0.35rem 0.75rem;
  background: rgba(56, 189, 248, 0.15);
  color: var(--color-primary);
  font-size: 0.8125rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  border-radius: 999px;
}
.hero-eyebrow i {
  font-size: 1rem;
}
.hero-title {
  margin: 0 0 1rem;
  font-size: clamp(1.75rem, 4vw, 2.75rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}
.hero-lead {
  margin: 0 0 2rem;
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
  font-size: 1.125rem;
  color: var(--color-text-muted);
}
.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
  justify-content: center;
}

/* Sections */
.section {
  padding: 3.5rem 0;
}
.section-title {
  margin: 0 0 0.5rem;
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  text-align: center;
}
.section-lead {
  margin: 0 0 2rem;
  text-align: center;
  color: var(--color-text-muted);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

/* Problems */
.section-problems {
  background: var(--color-bg-card);
}
.problems-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}
.problem-card {
  padding: 1.5rem;
  background: var(--color-bg);
  border-radius: var(--radius-lg);
  border: 1px solid rgba(255, 255, 255, 0.06);
  transition: border-color var(--transition), box-shadow var(--transition);
}
.problem-card:hover {
  border-color: rgba(56, 189, 248, 0.3);
  box-shadow: var(--shadow);
}
.problem-icon {
  display: block;
  margin-bottom: 0.75rem;
  color: var(--color-primary);
}
.problem-icon i {
  font-size: 1.75rem;
}
.problem-card h3 {
  margin: 0 0 0.5rem;
  font-size: 1.125rem;
  font-weight: 600;
}
.problem-card p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

/* Solution */
.solution-visual {
  display: flex;
  flex-direction: column;
  gap: 1rem;
  max-width: 640px;
  margin: 0 auto;
}
.solution-box {
  padding: 1.25rem 1.5rem;
  background: var(--color-bg-card);
  border-radius: var(--radius);
  border-left: 4px solid var(--color-primary);
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}
.solution-box strong {
  color: var(--color-text);
}

/* Features */
.section-features {
  background: var(--color-bg-card);
}
.features-list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 560px;
  margin: 0 auto;
}
.features-list li {
  position: relative;
  padding-left: 1.75rem;
  margin-bottom: 0.875rem;
  font-size: 1rem;
}
.features-list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 0.5rem;
  width: 8px;
  height: 8px;
  background: var(--color-accent);
  border-radius: 50%;
}

/* CTA */
.section-cta {
  text-align: center;
  padding: 4rem 0;
}
.cta-note {
  margin-top: 1rem;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* Footer */
.footer {
  padding: 1.5rem 0;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  text-align: center;
}
.footer-copy {
  margin: 0;
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

/* WhatsApp float */
.whatsapp-float {
  position: fixed;
  bottom: 1.5rem;
  right: 1.5rem;
  z-index: 40;
  width: 56px;
  height: 56px;
  background: var(--color-whatsapp);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 20px rgba(37, 211, 102, 0.5);
  transition: transform var(--transition), box-shadow var(--transition);
}
.whatsapp-float:hover {
  transform: scale(1.05);
  box-shadow: 0 6px 24px rgba(37, 211, 102, 0.6);
}
.whatsapp-float:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.whatsapp-float-icon {
  font-size: 1.75rem;
  color: #fff;
}

/* Modal «Получить демо» */
.modal {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1rem;
  visibility: hidden;
  opacity: 0;
  transition: visibility var(--transition), opacity var(--transition);
}
.modal[aria-hidden="false"],
.modal.is-open {
  visibility: visible;
  opacity: 1;
}
.modal[aria-hidden="false"] .modal-dialog,
.modal.is-open .modal-dialog {
  transform: scale(1);
}
.modal-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  cursor: pointer;
}
.modal-dialog {
  position: relative;
  width: 100%;
  max-width: 420px;
  max-height: 90vh;
  overflow-y: auto;
  background: var(--color-bg-card);
  border-radius: var(--radius-lg);
  padding: 2rem;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: var(--shadow);
  transform: scale(0.95);
  transition: transform var(--transition);
}
.modal-close {
  position: absolute;
  top: 1rem;
  right: 1rem;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  border-radius: var(--radius);
  transition: color var(--transition), background var(--transition);
}
.modal-close:hover {
  color: var(--color-text);
  background: var(--color-bg-elevated);
}
.modal-close:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.modal-title {
  margin: 0 0 0.5rem;
  font-size: 1.5rem;
  font-weight: 700;
}
.modal-lead {
  margin: 0 0 1.5rem;
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}
.modal-form {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.modal-label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 0.25rem;
  color: var(--color-text);
}
.modal-input {
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-family: var(--font);
  font-size: 1rem;
  color: var(--color-text);
  background: var(--color-bg);
  border: 1px solid rgba(255, 255, 255, 0.15);
  border-radius: var(--radius);
  transition: border-color var(--transition);
}
.modal-input::placeholder {
  color: var(--color-text-muted);
}
.modal-input:focus {
  outline: none;
  border-color: var(--color-primary);
}
.modal-submit {
  margin-top: 0.5rem;
  width: 100%;
}

/* Секция «Налоги и отчётность» */
.section-tax {
  background: var(--color-bg);
}
.tax-list {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 720px;
  margin: 0 auto;
}
.tax-item {
  display: flex;
  gap: 1.25rem;
  align-items: flex-start;
  padding: 1.25rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.tax-item:last-child {
  border-bottom: none;
}
.tax-icon {
  flex-shrink: 0;
  width: 48px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(56, 189, 248, 0.15);
  color: var(--color-primary);
  border-radius: var(--radius);
}
.tax-icon i {
  font-size: 1.25rem;
}
.tax-item h3 {
  margin: 0 0 0.35rem;
  font-size: 1.0625rem;
  font-weight: 600;
}
.tax-item p {
  margin: 0;
  font-size: 0.9375rem;
  color: var(--color-text-muted);
}

/* FAQ */
.section-faq {
  background: var(--color-bg-card);
}
.faq-list {
  margin: 0;
  padding: 0;
  max-width: 640px;
  margin: 0 auto;
}
.faq-item {
  margin: 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}
.faq-item:last-child {
  border-bottom: none;
}
.faq-question {
  margin: 0;
}
.faq-trigger {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 1.125rem 0;
  font-family: var(--font);
  font-size: 1rem;
  font-weight: 600;
  color: var(--color-text);
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  transition: color var(--transition);
}
.faq-trigger:hover {
  color: var(--color-primary);
}
.faq-trigger:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}
.faq-chevron {
  flex-shrink: 0;
  font-size: 0.75rem;
  color: var(--color-primary);
  transition: transform var(--transition);
}
.faq-item.is-open .faq-chevron {
  transform: rotate(-180deg);
}
.faq-answer {
  margin: 0 0 0 1.5rem;
  padding: 0 0 1.125rem;
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.6;
}
.faq-answer[hidden] {
  display: none;
}

/* Mobile */
@media (max-width: 768px) {
  .nav {
    display: none;
  }
  .nav.is-open {
    display: flex;
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    padding: 1rem;
    background: var(--color-bg-card);
    border-bottom: 1px solid rgba(255,255,255,0.06);
  }
  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: none;
    color: var(--color-text);
    cursor: pointer;
  }
  .menu-toggle[hidden] {
    display: none;
  }
  .hero {
    padding: 3rem 0 4rem;
  }
  .section {
    padding: 2.5rem 0;
  }
  .whatsapp-float {
    bottom: 1rem;
    right: 1rem;
    width: 52px;
    height: 52px;
  }
}

@media (min-width: 769px) {
  .menu-toggle[hidden] {
    display: none;
  }
}