/* ============================================================
   GLOBAL.CSS — Bohdan Shevchenko Portfolio
   Design tokens, reset, typography, shared components, utilities
   ============================================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Space+Grotesk:wght@400;500;600;700&family=Inter:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500;600&display=swap');

/* === DESIGN TOKENS === */
:root {
  /* Colors — Primary */
  --color-primary: #2D3748;
  --color-primary-light: #4A5568;
  --color-primary-dark: #1A202C;

  /* Colors — Accent (CTA) */
  --color-accent: #F56565;
  --color-accent-hover: #E53E3E;
  --color-accent-light: #FED7D7;

  /* Colors — Secondary */
  --color-secondary: #319795;
  --color-secondary-light: #E6FFFA;
  --color-secondary-dark: #285E61;

  /* Colors — Neutrals */
  --color-bg: #FFFFFF;
  --color-bg-alt: #F7FAFC;
  --color-bg-dark: #1A202C;
  --color-bg-dark-alt: #2D3748;

  /* Colors — Text */
  --color-text: #1A202C;
  --color-text-secondary: #718096;
  --color-text-light: #A0AEC0;
  --color-text-on-dark: #F7FAFC;
  --color-text-on-dark-secondary: #CBD5E0;

  /* Colors — Borders */
  --color-border: #E2E8F0;
  --color-border-light: #EDF2F7;

  /* Typography */
  --font-display: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', monospace;

  /* Font Sizes — Fluid */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: clamp(1.25rem, 2.5vw, 1.5rem);
  --text-3xl: clamp(1.5rem, 3vw, 1.875rem);
  --text-4xl: clamp(1.875rem, 4vw, 2.25rem);
  --text-5xl: clamp(2.25rem, 5vw, 3rem);
  --text-6xl: clamp(2.5rem, 5.5vw, 3.75rem);

  /* Font Weights */
  --font-normal: 400;
  --font-medium: 500;
  --font-semibold: 600;
  --font-bold: 700;
  --font-extrabold: 800;

  /* Line Heights */
  --leading-tight: 1.2;
  --leading-snug: 1.375;
  --leading-normal: 1.5;
  --leading-relaxed: 1.625;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --section-padding: clamp(3rem, 8vw, 6rem);
  --container-padding: clamp(1.25rem, 4vw, 2rem);

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

  /* Borders */
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.07), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.08), 0 4px 6px -2px rgba(0, 0, 0, 0.04);
  --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.08), 0 10px 10px -5px rgba(0, 0, 0, 0.03);

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
}


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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
  -webkit-text-size-adjust: 100%;
}

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

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

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

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

ul, ol {
  list-style: none;
}

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


/* === TYPOGRAPHY === */
.heading-1 {
  font-size: var(--text-6xl);
  font-weight: var(--font-bold);
  letter-spacing: -0.025em;
}

.heading-2 {
  font-size: var(--text-5xl);
  font-weight: var(--font-bold);
  letter-spacing: -0.02em;
}

.heading-3 {
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  letter-spacing: -0.015em;
}

.heading-4 {
  font-size: var(--text-3xl);
  font-weight: var(--font-semibold);
}

.heading-5 {
  font-size: var(--text-2xl);
  font-weight: var(--font-semibold);
}

.kicker {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

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

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


/* === LAYOUT UTILITIES === */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

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

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

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

.section--dark {
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark);
}

.section--dark h2,
.section--dark h3,
.section--dark h4 {
  color: var(--color-text-on-dark);
}

.section--dark p,
.section--dark .body-lg {
  color: var(--color-text-on-dark-secondary);
}

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

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


/* === BUTTONS === */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--font-semibold);
  padding: 0.875rem 2rem;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  white-space: nowrap;
  text-decoration: none;
}

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

.btn--primary:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-1px);
  box-shadow: var(--shadow-lg);
}

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

.btn--outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-1px);
}

.btn--dark-outline {
  background-color: transparent;
  color: var(--color-text-on-dark);
  border: 2px solid rgba(255, 255, 255, 0.3);
}

.btn--dark-outline:hover {
  border-color: rgba(255, 255, 255, 0.7);
  transform: translateY(-1px);
}

.btn--sm {
  font-size: var(--text-sm);
  padding: 0.625rem 1.25rem;
}

.btn--lg {
  font-size: var(--text-lg);
  padding: 1rem 2.5rem;
}


/* === TRUST BAR === */
.trust-bar {
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark-secondary);
  padding: 0.625rem 0;
  font-size: var(--text-sm);
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.trust-bar__inner {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: var(--space-6);
  flex-wrap: wrap;
}

.trust-bar__item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: var(--font-medium);
}

.trust-bar__item svg {
  width: 16px;
  height: 16px;
  fill: var(--color-accent);
  flex-shrink: 0;
}

.trust-bar__divider {
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background-color: rgba(255, 255, 255, 0.3);
}


/* === HEADER === */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--color-border-light);
  height: var(--header-height);
  transition: box-shadow var(--transition-base);
}

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

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

.header__logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-text);
  letter-spacing: -0.02em;
}

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

.header__nav {
  display: none;
  align-items: center;
  gap: var(--space-8);
}

.header__link {
  font-size: var(--text-sm);
  font-weight: var(--font-medium);
  color: var(--color-text-secondary);
  transition: color var(--transition-fast);
  position: relative;
}

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

.header__link--active::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-accent);
  border-radius: 1px;
}

.header__cta {
  display: none;
}

/* Hamburger */
.hamburger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 28px;
  height: 28px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 0;
}

.hamburger span {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: all var(--transition-base);
  transform-origin: center;
}

.hamburger--open span:first-child {
  transform: translateY(7px) rotate(45deg);
}

.hamburger--open span:nth-child(2) {
  opacity: 0;
}

.hamburger--open span:last-child {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Nav */
.mobile-nav {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(10px);
  z-index: 99;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
  opacity: 0;
  visibility: hidden;
  transition: all var(--transition-base);
}

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

.mobile-nav__link {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: var(--font-semibold);
  color: var(--color-text);
  transition: color var(--transition-fast);
}

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


/* === SECTION HEADER (reusable) === */
.section-header {
  text-align: center;
  max-width: 700px;
  margin: 0 auto var(--space-12);
}

.section-header .kicker {
  margin-bottom: var(--space-3);
  display: block;
}

.section-header h2 {
  margin-bottom: var(--space-4);
}

.section-header .body-lg {
  margin: 0 auto;
}


/* === CARDS === */
.card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-8);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-border-light);
}

.card--flat {
  border: none;
  background-color: var(--color-bg-alt);
}

.card--flat:hover {
  background-color: var(--color-bg);
  box-shadow: var(--shadow-lg);
}


/* === TAGS / BADGES === */
.tag {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  background-color: var(--color-secondary-light);
  color: var(--color-secondary-dark);
}

.tag--accent {
  background-color: var(--color-accent-light);
  color: var(--color-accent-hover);
}

.tag--dark {
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark);
}


/* === METRIC DISPLAY === */
.metric {
  text-align: center;
}

.metric__value {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: var(--font-bold);
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.metric__label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  margin-top: var(--space-1);
}

.section--dark .metric__value {
  color: var(--color-text-on-dark);
}

.section--dark .metric__label {
  color: var(--color-text-on-dark-secondary);
}


/* === FOOTER === */
.footer {
  background-color: var(--color-bg-dark);
  color: var(--color-text-on-dark-secondary);
  padding: var(--space-16) 0 var(--space-8);
}

.footer__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-10);
  margin-bottom: var(--space-12);
}

.footer__brand {
  max-width: 360px;
}

.footer__logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--font-bold);
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-4);
}

.footer__logo span {
  color: var(--color-accent);
}

.footer__desc {
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  margin-bottom: var(--space-6);
}

.footer__social {
  display: flex;
  gap: var(--space-4);
}

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

.footer__social-link:hover {
  background-color: var(--color-accent);
  color: #FFFFFF;
}

.footer__social-link svg {
  width: 18px;
  height: 18px;
  fill: currentColor;
}

.footer__heading {
  font-family: var(--font-display);
  font-size: var(--text-sm);
  font-weight: var(--font-semibold);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-on-dark);
  margin-bottom: var(--space-4);
}

.footer__links {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.footer__link {
  font-size: var(--text-sm);
  color: var(--color-text-on-dark-secondary);
  transition: color var(--transition-fast);
}

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

.footer__bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.1);
  padding-top: var(--space-8);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-3);
  text-align: center;
}

.footer__copyright {
  font-size: var(--text-sm);
}

.footer__built {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  color: var(--color-text-light);
}


/* === SCROLL ANIMATIONS === */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal--visible {
  opacity: 1;
  transform: translateY(0);
}

.reveal--delay-1 { transition-delay: 0.1s; }
.reveal--delay-2 { transition-delay: 0.2s; }
.reveal--delay-3 { transition-delay: 0.3s; }
.reveal--delay-4 { transition-delay: 0.4s; }


/* === FOCUS STATES (Accessibility) === */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
  border-radius: 2px;
}

a:focus-visible,
button:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}


/* === RESPONSIVE — Tablet+ === */
@media (min-width: 768px) {
  .header__nav {
    display: flex;
  }

  .header__cta {
    display: inline-flex;
  }

  .hamburger {
    display: none;
  }

  .mobile-nav {
    display: none;
  }

  .footer__grid {
    grid-template-columns: 2fr 1fr 1fr;
  }

  .footer__bottom {
    flex-direction: row;
    justify-content: space-between;
  }
}