/* =============================================================
   ALG Intelligence — Landing Page Stylesheet
   Dark theme | Modern | Conversion-optimized
   ============================================================= */

/* --------------------------------------------------------------
   1. CUSTOM PROPERTIES (Design Tokens)
   -------------------------------------------------------------- */
:root {
  --color-bg: #0a0e1a;
  --color-bg-alt: #111827;
  --color-bg-card: #111827;
  --color-bg-elevated: #1a1f2e;
  --color-accent: #3b82f6;
  --color-accent-hover: #2563eb;
  --color-accent-glow: rgba(59, 130, 246, 0.25);
  --color-accent-light: rgba(59, 130, 246, 0.1);
  --color-green: #22c55e;
  --color-yellow: #f59e0b;
  --color-red: #ef4444;
  --color-text: #f8fafc;
  --color-text-muted: #94a3b8;
  --color-text-dim: #64748b;
  --color-border: #1e293b;
  --color-border-light: #334155;

  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

  --max-width: 1200px;
  --header-height: 72px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 24px var(--color-accent-glow);

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

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--header-height);
}

body {
  font-family: var(--font-primary);
  font-size: 16px;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul {
  list-style: none;
}

/* --------------------------------------------------------------
   3. TYPOGRAPHY
   -------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

code, pre {
  font-family: var(--font-mono);
}

/* --------------------------------------------------------------
   4. LAYOUT UTILITIES
   -------------------------------------------------------------- */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.section-header {
  text-align: center;
  margin-bottom: 56px;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 12px;
  color: var(--color-text);
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  max-width: 600px;
  margin: 0 auto;
}

section {
  padding: 96px 0;
}

/* --------------------------------------------------------------
   5. BUTTONS
   -------------------------------------------------------------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-primary);
  font-size: 0.9375rem;
  font-weight: 600;
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  border: 1.5px solid transparent;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  white-space: nowrap;
}

.btn--primary {
  background: var(--color-accent);
  color: #ffffff;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 0 var(--color-accent-glow);
}

.btn--primary:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  box-shadow: 0 0 24px var(--color-accent-glow);
  transform: translateY(-1px);
  color: #ffffff;
}

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

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

.btn--lg {
  padding: 14px 32px;
  font-size: 1rem;
}

/* --------------------------------------------------------------
   6. HEADER / NAVIGATION
   -------------------------------------------------------------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(10, 14, 26, 0.8);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition-base);
}

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

.logo {
  display: flex;
  align-items: center;
  flex-shrink: 0;
}

.nav__list {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav__link {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text-muted);
  position: relative;
  padding: 4px 0;
}

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

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

.nav__link:hover::after {
  width: 100%;
}

.nav__cta {
  flex-shrink: 0;
}

/* --------------------------------------------------------------
   7. HERO
   -------------------------------------------------------------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: calc(var(--header-height) + 48px) 0 80px;
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.06) 0%, transparent 70%);
  pointer-events: none;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: center;
}

.hero__content {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.hero__badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 6px 14px;
  border-radius: 100px;
  width: fit-content;
  letter-spacing: 0.02em;
}

.hero__headline {
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -0.03em;
}

.hero__accent {
  background: linear-gradient(135deg, var(--color-accent), #60a5fa);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__subheadline {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  max-width: 540px;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 8px;
}

.hero__social-proof {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
  margin-top: 4px;
}

.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}

.hero__img {
  width: 100%;
  height: auto;
  max-width: 600px;
  filter: drop-shadow(0 8px 32px rgba(59, 130, 246, 0.1));
}

/* --------------------------------------------------------------
   8. VALUE PROPOSITION
   -------------------------------------------------------------- */
.value-prop {
  background: var(--color-bg-alt);
}

.value-prop__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
}

.value-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  transition: all var(--transition-base);
}

.value-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.value-card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: 20px;
}

.value-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 10px;
}

.value-card__text {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --------------------------------------------------------------
   9. SERVICES
   -------------------------------------------------------------- */
.services__grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.service-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 28px 22px;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--color-accent), transparent);
  opacity: 0;
  transition: opacity var(--transition-base);
}

.service-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.service-card:hover::before {
  opacity: 1;
}

.service-card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
}

.service-card__title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.service-card__text {
  font-size: 0.8125rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

.service-card__text strong {
  color: var(--color-accent);
  font-weight: 600;
}

/* --------------------------------------------------------------
   10. TECH STACK
   -------------------------------------------------------------- */
.tech-stack {
  background: var(--color-bg-alt);
}

.tech-stack__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.tech-category__title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
  margin-bottom: 12px;
}

.tech-list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tech-badge {
  display: inline-flex;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 6px 14px;
  border-radius: 100px;
  border: 1px solid transparent;
  transition: all var(--transition-base);
}

.tech-badge:hover {
  border-color: var(--color-accent);
  box-shadow: 0 0 12px var(--color-accent-glow);
  transform: translateY(-1px);
}

/* --------------------------------------------------------------
    11. CORE SKILLS SUMMARY
   -------------------------------------------------------------- */
.core-skills {
  background: var(--color-bg-alt);
}

.core-skills__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.skill-category__title {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--color-border);
}

.skill-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.skill-item {
  font-size: 0.875rem;
  color: var(--color-text);
  padding: 6px 12px;
  background: var(--color-bg-elevated);
  border-radius: 6px;
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
}

.skill-item:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
  transform: translateX(4px);
}

/* --------------------------------------------------------------
    12. WHY ME
   -------------------------------------------------------------- */
.why-me__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 32px;
}

.why-card {
  text-align: center;
  padding: 40px 24px;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  transition: all var(--transition-base);
}

.why-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.why-card__number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: var(--color-accent-light);
  color: var(--color-accent);
  font-size: 1.25rem;
  font-weight: 800;
  font-family: var(--font-mono);
  margin-bottom: 20px;
}

.why-card__title {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 12px;
}

.why-card__text {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* --------------------------------------------------------------
   13. PORTFOLIO
   -------------------------------------------------------------- */
.portfolio {
  background: var(--color-bg-alt);
}

.portfolio__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.portfolio-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-base);
}

.portfolio-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.portfolio-card__image {
  background: var(--color-bg-elevated);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 32px;
  aspect-ratio: 16 / 9;
  border-bottom: 1px solid var(--color-border);
}

.portfolio-card__img {
  width: 80px;
  height: 80px;
  opacity: 0.6;
}

.portfolio-card__body {
  padding: 24px;
}

.portfolio-card__tag {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  background: var(--color-accent-light);
  padding: 4px 10px;
  border-radius: 4px;
  margin-bottom: 12px;
}

.portfolio-card__title {
  font-size: 1.125rem;
  font-weight: 700;
  margin-bottom: 8px;
}

.portfolio-card__text {
  font-size: 0.875rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}


/* --------------------------------------------------------------
   14. TESTIMONIALS
   -------------------------------------------------------------- */
.testimonials {
  background: var(--color-bg-alt);
}

.testimonials__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.testimonial-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 32px 24px;
  position: relative;
  transition: all var(--transition-base);
}

.testimonial-card:hover {
  border-color: var(--color-border-light);
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
}

.testimonial-card__avatar {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: 16px;
}

.testimonial-card__text {
  font-size: 0.9375rem;
  color: var(--color-text);
  line-height: 1.7;
  margin-bottom: 20px;
  font-style: italic;
}

.testimonial-card__author {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.testimonial-card__name {
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--color-text);
}

.testimonial-card__role {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}

/* --------------------------------------------------------------
   15. FINAL CTA
   -------------------------------------------------------------- */
.cta-final {
  text-align: center;
  position: relative;
  overflow: hidden;
}

.cta-final::before {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, rgba(59, 130, 246, 0.05) 0%, transparent 70%);
  pointer-events: none;
}

.cta-final__inner {
  position: relative;
  z-index: 1;
  max-width: 640px;
  margin: 0 auto;
}

.cta-final__headline {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  margin-bottom: 16px;
}

.cta-final__text {
  font-size: 1.125rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 32px;
}

.cta-final__actions {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.cta-final__alt {
  font-size: 0.875rem;
  color: var(--color-text-dim);
  margin-top: 16px;
}

.cta-final__alt a {
  color: var(--color-accent);
  font-weight: 500;
}

/* --------------------------------------------------------------
   16. FOOTER
   -------------------------------------------------------------- */
.site-footer {
  background: var(--color-bg-alt);
  border-top: 1px solid var(--color-border);
  padding: 64px 0 48px;
}

.footer__inner {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 40px;
}

.footer__tagline {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
  margin-top: 12px;
  line-height: 1.6;
  max-width: 320px;
}

.footer__heading {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-text-dim);
  margin-bottom: 16px;
}

.footer__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__list a {
  font-size: 0.875rem;
  color: var(--color-text-muted);
}

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

.footer__copyright {
  grid-column: 1 / -1;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
  margin-top: 32px;
}

.footer__copyright p {
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}

.footer__tech {
  font-family: var(--font-mono);
  font-size: 0.75rem;
}

/* --------------------------------------------------------------
   17. SCROLL ANIMATIONS
   -------------------------------------------------------------- */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.hero__content {
  animation: fadeInUp 0.8s ease forwards;
}

.hero__visual {
  animation: fadeInUp 0.8s ease 0.2s forwards;
  opacity: 0;
}

/* --------------------------------------------------------------
   18. RESPONSIVE — TABLETS (max-width: 1024px)
   -------------------------------------------------------------- */
@media (max-width: 1024px) {
  .hero__inner {
    grid-template-columns: 1fr;
    gap: 40px;
    text-align: center;
  }

  .hero__content {
    align-items: center;
  }

  .hero__badge {
    margin: 0 auto;
  }

  .hero__subheadline {
    max-width: 100%;
  }

  .hero__actions {
    justify-content: center;
  }

  .hero__visual {
    order: -1;
  }

  .hero__img {
    max-width: 480px;
  }

  .value-prop__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .tech-stack__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .core-skills__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .why-me__grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }

  .portfolio__grid {
    grid-template-columns: 1fr;
    max-width: 540px;
    margin: 0 auto;
  }

  .testimonials__grid {
    grid-template-columns: 1fr;
    max-width: 480px;
    margin: 0 auto;
  }

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

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

  .nav__list {
    display: none;
  }
}

/* --------------------------------------------------------------
   19. RESPONSIVE — MOBILE (max-width: 768px)
   -------------------------------------------------------------- */
@media (max-width: 768px) {
  :root {
    --header-height: 64px;
  }

  section {
    padding: 64px 0;
  }

  .container {
    padding: 0 16px;
  }

  .section-header {
    margin-bottom: 40px;
  }

  .btn--lg {
    padding: 12px 24px;
    font-size: 0.9375rem;
  }

  .hero {
    padding: calc(var(--header-height) + 32px) 0 48px;
    min-height: auto;
  }

  .hero__headline {
    font-size: clamp(1.5rem, 6vw, 2rem);
  }

  .hero__subheadline {
    font-size: 1rem;
  }

  .hero__actions {
    flex-direction: column;
    width: 100%;
  }

  .hero__actions .btn {
    width: 100%;
    justify-content: center;
  }

  .value-prop__grid {
    grid-template-columns: 1fr;
  }

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

  .tech-stack__grid {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .core-skills__grid {
    grid-template-columns: 1fr;
  }

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

  .cta-final__actions {
    flex-direction: column;
    align-items: center;
  }

  .cta-final__actions .btn {
    width: 100%;
    justify-content: center;
  }

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

  .footer__copyright {
    flex-direction: column;
    gap: 8px;
    text-align: center;
  }

  .nav__cta {
    display: none;
  }
}

/* --------------------------------------------------------------
   20. REDUCED MOTION
   -------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

  html {
    scroll-behavior: auto;
  }
}