/* ===========================================
   Main Styles - Yehor Herasymchuk
   =========================================== */

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

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

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

body {
  font-family: var(--font-primary);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base), color var(--transition-base);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.3;
  color: var(--color-text);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
  margin-bottom: var(--space-4);
  color: var(--color-text-secondary);
}

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

a:hover {
  color: var(--color-accent-hover);
}

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

/* Container */
.container {
  width: 100%;
  max-width: var(--container-lg);
  margin: 0 auto;
  padding: 0 var(--space-4);
}

@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-6);
  }
}

/* Header */
.header {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  transition: background-color var(--transition-base), border-color var(--transition-base);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.header__logo {
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text);
  text-decoration: none;
}

.header__logo:hover {
  color: var(--color-accent);
}

/* Navigation */
.nav {
  display: none;
}

@media (min-width: 768px) {
  .nav {
    display: flex;
    align-items: center;
    gap: var(--space-6);
  }
}

.nav__link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  text-decoration: none;
  padding: var(--space-2) 0;
  position: relative;
  transition: color var(--transition-fast);
}

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

.nav__link--active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-accent);
}

/* Header Actions */
.header__actions {
  display: flex;
  align-items: center;
  gap: var(--space-3);
}

/* Language Switcher */
.lang-switch {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-2);
  background-color: var(--color-bg-secondary);
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
}

.lang-switch__btn {
  padding: var(--space-1) var(--space-2);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
  background: none;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
}

.lang-switch__btn:hover {
  color: var(--color-text);
}

.lang-switch__btn--active {
  background-color: var(--color-accent);
  color: white;
}

.lang-switch__btn--active:hover {
  color: white;
}

/* Theme Toggle */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  color: var(--color-text-secondary);
}

.theme-toggle:hover {
  border-color: var(--color-border-hover);
  color: var(--color-text);
}

.theme-toggle__icon {
  width: 20px;
  height: 20px;
}

.theme-toggle__icon--dark {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--light {
  display: none;
}

[data-theme="dark"] .theme-toggle__icon--dark {
  display: block;
}

/* Mobile Menu Button */
.mobile-menu-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  color: var(--color-text);
}

@media (min-width: 768px) {
  .mobile-menu-btn {
    display: none;
  }
}

.mobile-menu-btn__icon {
  width: 20px;
  height: 20px;
}

/* Mobile Menu */
.mobile-menu {
  position: fixed;
  top: 64px;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: var(--color-bg);
  padding: var(--space-6);
  transform: translateX(100%);
  transition: transform var(--transition-base);
  z-index: var(--z-modal);
}

.mobile-menu--open {
  transform: translateX(0);
}

@media (min-width: 768px) {
  .mobile-menu {
    display: none;
  }
}

.mobile-menu__nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.mobile-menu__link {
  font-size: var(--text-lg);
  font-weight: 500;
  color: var(--color-text);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--color-border);
}

/* Main Content */
main {
  flex: 1;
  padding: var(--space-12) 0;
}

/* Section */
.section {
  margin-bottom: var(--space-16);
}

.section__title {
  margin-bottom: var(--space-8);
}

/* Hero Section */
.hero {
  padding: var(--space-16) 0;
  text-align: center;
}

@media (min-width: 768px) {
  .hero {
    padding: var(--space-20) 0;
    text-align: left;
  }
}

.hero__content {
  max-width: 640px;
}

@media (min-width: 768px) {
  .hero__content {
    max-width: 720px;
  }
}

.hero__greeting {
  display: inline-block;
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
  padding: var(--space-1) var(--space-3);
  background-color: var(--color-accent-light);
  border-radius: var(--radius-full);
}

.hero__title {
  font-size: var(--text-4xl);
  margin-bottom: var(--space-4);
}

@media (min-width: 768px) {
  .hero__title {
    font-size: var(--text-5xl);
  }
}

.hero__subtitle {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-8);
}

@media (min-width: 768px) {
  .hero__subtitle {
    font-size: var(--text-xl);
  }
}

.hero__cta {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

@media (min-width: 480px) {
  .hero__cta {
    flex-direction: row;
    justify-content: center;
  }
}

@media (min-width: 768px) {
  .hero__cta {
    justify-content: flex-start;
  }
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  font-size: var(--text-sm);
  font-weight: 500;
  text-decoration: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: none;
}

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

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

.btn--secondary {
  background-color: var(--color-bg-secondary);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

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

.btn--large {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
}

/* Footer */
.footer {
  background-color: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-12) 0;
  margin-top: auto;
}

.footer__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-8);
}

@media (min-width: 768px) {
  .footer__inner {
    flex-direction: row;
    justify-content: space-between;
    align-items: center;
  }
}

.footer__info {
  text-align: center;
}

@media (min-width: 768px) {
  .footer__info {
    text-align: left;
  }
}

.footer__name {
  font-size: var(--text-lg);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-2);
}

.footer__copy {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin: 0;
}

/* Social Links */
.social-links {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
}

@media (min-width: 768px) {
  .social-links {
    justify-content: flex-end;
  }
}

.social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  color: var(--color-text-secondary);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--transition-fast);
}

.social-link:hover {
  color: var(--color-accent);
  border-color: var(--color-accent);
}

.social-link__icon {
  width: 20px;
  height: 20px;
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.mt-4 { margin-top: var(--space-4); }
.mt-8 { margin-top: var(--space-8); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-8 { margin-bottom: var(--space-8); }

.hidden { display: none; }

@media (max-width: 767px) {
  .hidden-mobile { display: none; }
}

@media (min-width: 768px) {
  .hidden-desktop { display: none; }
}