/**
 * Podpisal.ru - Main Styles
 * Основные стили лендинга
 */

/* ============================================
   CSS Variables
   ============================================ */

:root {
  /* Colors */
  --color-primary: #2563eb;
  --color-primary-dark: #1d4ed8;
  --color-primary-light: #3b82f6;

  --color-secondary: #10b981;
  --color-secondary-dark: #059669;

  --color-text: #1f2937;
  --color-text-secondary: #6b7280;
  --color-text-muted: #9ca3af;

  --color-bg: #ffffff;
  --color-bg-secondary: #f9fafb;
  --color-bg-tertiary: #f3f4f6;

  --color-border: #e5e7eb;
  --color-border-light: #f3f4f6;

  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;
  --spacing-4xl: 6rem;

  /* Border Radius */
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.1);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 200ms ease;
  --transition-slow: 300ms ease;

  /* Layout */
  --container-max: 1200px;
  --container-narrow: 800px;
  --header-height: 72px;
}

/* ============================================
   Reset & Base
   ============================================ */

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body.no-scroll {
  overflow: hidden;
}

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

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

a:hover {
  color: var(--color-primary-dark);
}

ul, ol {
  list-style: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

input, select, textarea {
  font-family: inherit;
  font-size: inherit;
}

/* Skip Link */
.skip-link {
  position: absolute;
  top: -100%;
  left: 0;
  background: var(--color-primary);
  color: white;
  padding: var(--spacing-sm) var(--spacing-md);
  z-index: 1000;
}

.skip-link:focus {
  top: 0;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
  line-height: var(--line-height-tight);
  font-weight: 700;
  color: var(--color-text);
}

h1 {
  font-size: var(--font-size-4xl);
  margin-bottom: var(--spacing-lg);
}

h2 {
  font-size: var(--font-size-3xl);
  margin-bottom: var(--spacing-md);
}

h3 {
  font-size: var(--font-size-2xl);
  margin-bottom: var(--spacing-md);
}

h4 {
  font-size: var(--font-size-xl);
  margin-bottom: var(--spacing-sm);
}

p {
  margin-bottom: var(--spacing-md);
}

.lead {
  font-size: var(--font-size-lg);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

@media (max-width: 768px) {
  h1 { font-size: var(--font-size-3xl); }
  h2 { font-size: var(--font-size-2xl); }
  h3 { font-size: var(--font-size-xl); }
}

/* ============================================
   Layout
   ============================================ */

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

.container--narrow {
  max-width: var(--container-narrow);
}

.section {
  padding: var(--spacing-4xl) 0;
}

.section--gray {
  background-color: var(--color-bg-secondary);
}

/* ============================================
   Buttons
   ============================================ */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-sm);
  padding: 0.75rem 1.5rem;
  font-size: var(--font-size-base);
  font-weight: 600;
  line-height: 1;
  border-radius: var(--radius-lg);
  transition: all var(--transition-fast);
  text-decoration: none;
  white-space: nowrap;
}

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

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

.btn--secondary {
  background-color: var(--color-bg-tertiary);
  color: var(--color-text);
}

.btn--secondary:hover {
  background-color: var(--color-border);
}

.btn--outline {
  background-color: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
}

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

.btn--sm {
  padding: 0.5rem 1rem;
  font-size: var(--font-size-sm);
}

.btn--lg {
  padding: 1rem 2rem;
  font-size: var(--font-size-lg);
}

.btn--block {
  width: 100%;
}

.btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

/* ============================================
   Header & Navigation
   ============================================ */

.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: var(--color-bg);
  transition: box-shadow var(--transition-normal);
}

.header.is-scrolled {
  box-shadow: var(--shadow-md);
}

.nav {
  height: var(--header-height);
}

.nav__container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.nav__logo {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text);
}

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

.logo-animated {
  width: 32px;
  height: 32px;
  color: var(--color-primary);
}

.logo-animated path {
  stroke-dasharray: 100;
  stroke-dashoffset: 100;
  animation: draw 2s ease forwards;
}

.logo-animated .logo-signature {
  stroke-dasharray: 20;
  stroke-dashoffset: 20;
  animation: draw 1s ease forwards 0.5s; /* Delay signature to start after document outline */
}

@keyframes draw {
  to {
    stroke-dashoffset: 0;
  }
}

.nav__links {
  display: flex;
  gap: var(--spacing-xl);
}

.nav__link {
  color: var(--color-text-secondary);
  font-weight: 500;
  transition: color var(--transition-fast);
}

.nav__link:hover,
.nav__link.active {
  color: var(--color-primary);
}

.nav__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
}

.nav__toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  padding: 4px;
}

.nav__toggle-bar {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition-fast);
}

.nav__toggle.is-active .nav__toggle-bar:nth-child(1) {
  transform: rotate(45deg) translate(5px, 5px);
}

.nav__toggle.is-active .nav__toggle-bar:nth-child(2) {
  opacity: 0;
}

.nav__toggle.is-active .nav__toggle-bar:nth-child(3) {
  transform: rotate(-45deg) translate(5px, -5px);
}

/* Mobile Menu */
.mobile-menu {
  display: none;
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  z-index: 99;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-normal), visibility var(--transition-normal);
}

.mobile-menu.is-open {
  opacity: 1;
  visibility: visible;
}

.mobile-menu__content {
  display: flex;
  flex-direction: column;
  padding: var(--spacing-xl);
  gap: var(--spacing-md);
}

.mobile-menu__link {
  display: block;
  padding: var(--spacing-md) 0;
  font-size: var(--font-size-lg);
  font-weight: 500;
  color: var(--color-text);
  border-bottom: 1px solid var(--color-border);
}

@media (max-width: 768px) {
  .nav__links,
  .nav__actions {
    display: none;
  }

  .nav__toggle {
    display: flex;
  }

  .mobile-menu {
    display: block;
  }
}

/* ============================================
   Main Content Offset
   ============================================ */

main {
  padding-top: var(--header-height);
}

/* ============================================
   Breadcrumbs
   ============================================ */

.breadcrumbs {
  padding: var(--spacing-md) 0;
  margin-bottom: var(--spacing-lg);
}

.breadcrumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--spacing-xs);
  list-style: none;
  padding: 0;
  margin: 0;
}

.breadcrumbs li {
  display: flex;
  align-items: center;
  font-size: var(--font-size-sm);
}

.breadcrumbs li:not(:last-child)::after {
  content: '/';
  margin-left: var(--spacing-xs);
  color: var(--color-text-muted);
}

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

.breadcrumbs a:hover {
  text-decoration: underline;
}

.breadcrumbs li:last-child span {
  color: var(--color-text-secondary);
}

/* ============================================
   CTA Block
   ============================================ */

.cta-block {
  background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-dark) 100%);
  border-radius: var(--radius-xl);
  padding: var(--spacing-2xl);
  text-align: center;
  margin: var(--spacing-2xl) 0;
}

.cta-block__title {
  color: white;
  margin-bottom: var(--spacing-sm);
}

.cta-block__text {
  color: rgba(255, 255, 255, 0.9);
  margin-bottom: var(--spacing-lg);
}

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

.cta-block .btn:hover {
  background-color: var(--color-bg-secondary);
}

/* ============================================
   Calculator Cards
   ============================================ */

.calc-card {
  display: block;
  position: relative;
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg);
  transition: all var(--transition-fast);
  text-decoration: none;
}

.calc-card:hover {
  border-color: var(--color-primary);
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.calc-card--popular {
  border-color: var(--color-primary);
}

.calc-card__badge {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  background-color: var(--color-primary);
  color: white;
  font-size: var(--font-size-xs);
  font-weight: 600;
  padding: var(--spacing-xs) var(--spacing-sm);
  border-radius: var(--radius-full);
}

.calc-card__title {
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
}

.calc-card__description {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
  margin-bottom: var(--spacing-md);
}

.calc-card__action {
  color: var(--color-primary);
  font-weight: 500;
  font-size: var(--font-size-sm);
}

/* ============================================
   Footer
   ============================================ */

.footer {
  background-color: var(--color-bg-secondary);
  padding: var(--spacing-3xl) 0 var(--spacing-xl);
  margin-top: var(--spacing-4xl);
}

.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--spacing-2xl);
  margin-bottom: var(--spacing-2xl);
}

.footer__brand {
  max-width: 300px;
}

.footer__logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text);
}

.footer__tagline {
  color: var(--color-text-secondary);
  margin-top: var(--spacing-sm);
}

.footer__bot {
  margin-top: var(--spacing-md);
}

.footer__bot a {
  color: var(--color-primary);
  font-weight: 500;
}

.footer__heading {
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--spacing-md);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
}

.footer__links a {
  color: var(--color-text-secondary);
  font-size: var(--font-size-sm);
}

.footer__links a:hover {
  color: var(--color-primary);
}

.footer__bottom {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: var(--spacing-xl);
  border-top: 1px solid var(--color-border);
}

.footer__legal,
.footer__copyright {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.footer__legal p {
  margin-bottom: var(--spacing-xs);
}

@media (max-width: 768px) {
  .footer__grid {
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
  }

  .footer__brand {
    grid-column: 1 / -1;
  }

  .footer__bottom {
    flex-direction: column;
    gap: var(--spacing-md);
    text-align: center;
  }
}

@media (max-width: 480px) {
  .footer__grid {
    grid-template-columns: 1fr;
  }
}

/* ============================================
   Forms
   ============================================ */

.form-group {
  margin-bottom: var(--spacing-lg);
}

.form-label {
  display: block;
  font-weight: 500;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text);
}

.form-input,
.form-select {
  width: 100%;
  padding: 0.75rem 1rem;
  font-size: var(--font-size-base);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  background-color: var(--color-bg);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-input:focus,
.form-select:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-input::placeholder {
  color: var(--color-text-muted);
}

/* ============================================
   FAQ
   ============================================ */

.faq__list {
  max-width: var(--container-narrow);
  margin: 0 auto;
}

.faq__item {
  border-bottom: 1px solid var(--color-border);
}

.faq__question {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 100%;
  padding: var(--spacing-lg) 0;
  font-size: var(--font-size-lg);
  font-weight: 500;
  text-align: left;
  color: var(--color-text);
  cursor: pointer;
}

.faq__question::after {
  content: '+';
  font-size: var(--font-size-xl);
  color: var(--color-text-muted);
  transition: transform var(--transition-fast);
}

.faq__item.is-open .faq__question::after {
  content: '−';
}

.faq__answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow);
}

.faq__item.is-open .faq__answer {
  max-height: 500px;
}

.faq__answer-content {
  padding-bottom: var(--spacing-lg);
  color: var(--color-text-secondary);
  line-height: var(--line-height-relaxed);
}

/* ============================================
   Utilities
   ============================================ */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.text-primary { color: var(--color-primary); }
.text-secondary { color: var(--color-text-secondary); }
.text-muted { color: var(--color-text-muted); }

.font-bold { font-weight: 700; }
.font-medium { font-weight: 500; }

.mt-0 { margin-top: 0; }
.mt-1 { margin-top: var(--spacing-sm); }
.mt-2 { margin-top: var(--spacing-md); }
.mt-3 { margin-top: var(--spacing-lg); }
.mt-4 { margin-top: var(--spacing-xl); }

.mb-0 { margin-bottom: 0; }
.mb-1 { margin-bottom: var(--spacing-sm); }
.mb-2 { margin-bottom: var(--spacing-md); }
.mb-3 { margin-bottom: var(--spacing-lg); }
.mb-4 { margin-bottom: var(--spacing-xl); }

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}