/* ============================================
   Sternal.IT — Landing Page
   Mobile-first, system font stack, CSS only
   ============================================ */

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

/* --- Custom Properties --- */
:root {
  --color-bg: #0a0e1a;
  --color-bg-alt: #0f1424;
  --color-surface: #151a2e;
  --color-surface-hover: #1c2240;
  --color-border: #1e2540;
  --color-text: #e0e4f0;
  --color-text-muted: #8891ab;
  --color-heading: #f0f2f8;
  --color-accent: #2563eb;
  --color-accent-hover: #3b82f6;
  --color-accent-glow: rgba(37, 99, 235, 0.15);
  --color-white: #ffffff;
  --color-success: #22c55e;
  --color-error: #ef4444;

  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Cascadia Code", "Fira Code", monospace;

  --fs-xs: 0.75rem;
  --fs-sm: 0.875rem;
  --fs-base: 1rem;
  --fs-md: 1.125rem;
  --fs-lg: 1.25rem;
  --fs-xl: 1.5rem;
  --fs-2xl: 2rem;
  --fs-3xl: 2.5rem;
  --fs-4xl: 3rem;

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

  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;

  --header-height: 72px;
  --max-width: 1120px;
  --transition: 200ms ease;
}

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

body {
  font-family: var(--font-family);
  font-size: var(--fs-base);
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

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

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

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

ul {
  list-style: none;
}

address {
  font-style: normal;
}

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

/* --- Section common --- */
.section__title {
  font-size: var(--fs-2xl);
  font-weight: 700;
  color: var(--color-heading);
  margin-bottom: var(--spacing-sm);
}

.section__lead {
  font-size: var(--fs-md);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-2xl);
}

/* --- Buttons --- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-xs);
  padding: 0.875rem 2rem;
  font-family: var(--font-family);
  font-size: var(--fs-base);
  font-weight: 600;
  line-height: 1;
  border: none;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background-color var(--transition), box-shadow var(--transition), transform var(--transition);
  white-space: nowrap;
}

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

.btn--primary:hover {
  background-color: var(--color-accent-hover);
  box-shadow: 0 0 24px var(--color-accent-glow);
  color: var(--color-white);
}

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

.btn--outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

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

/* ============================
   HEADER
   ============================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: rgba(10, 14, 26, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

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

.header__logo {
  display: flex;
  align-items: center;
}

.header__logo-img {
  height: 32px;
  width: auto;
}

.header__menu {
  display: none;
  align-items: center;
  gap: var(--spacing-lg);
}

.header__link {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  font-weight: 500;
  transition: color var(--transition);
}

.header__link:hover {
  color: var(--color-heading);
}

.header__link--cta {
  color: var(--color-accent);
}

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

/* Burger */
.header__burger {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 32px;
  height: 32px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.header__burger-line {
  display: block;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition), opacity var(--transition);
}

.header__burger[aria-expanded="true"] .header__burger-line:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.header__burger[aria-expanded="true"] .header__burger-line:nth-child(2) {
  opacity: 0;
}

.header__burger[aria-expanded="true"] .header__burger-line:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* Mobile Menu */
.mobile-menu {
  position: fixed;
  top: var(--header-height);
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 99;
  background-color: rgba(10, 14, 26, 0.97);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 300ms ease, visibility 300ms ease;
}

.mobile-menu[hidden] {
  display: none;
}

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

.mobile-menu__list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--spacing-xl);
}

.mobile-menu__link {
  font-size: var(--fs-xl);
  font-weight: 600;
  color: var(--color-text);
  transition: color var(--transition);
}

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

.mobile-menu__link--cta {
  color: var(--color-accent);
}

/* ============================
   HERO
   ============================ */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  min-height: 100vh;
  min-height: 100dvh;
  padding: calc(var(--header-height) + var(--spacing-2xl)) 0 var(--spacing-3xl);
  background: linear-gradient(160deg, #0a0e1a 0%, #0f1a3a 40%, #101830 70%, #0a0e1a 100%);
  overflow: hidden;
}

/* Animated grid */
.hero__grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(59, 130, 246, 0.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(59, 130, 246, 0.04) 1px, transparent 1px);
  background-size: 60px 60px;
  animation: gridMove 20s linear infinite;
}

@keyframes gridMove {
  0% { background-position: 0 0; }
  100% { background-position: 60px 60px; }
}

/* Glow */
.hero__glow {
  position: absolute;
  top: 20%;
  left: 50%;
  width: 600px;
  height: 400px;
  transform: translateX(-50%);
  background: radial-gradient(ellipse, var(--color-accent-glow) 0%, transparent 70%);
  filter: blur(80px);
  animation: glowPulse 6s ease-in-out infinite alternate;
  pointer-events: none;
}

@keyframes glowPulse {
  0% { opacity: 0.4; transform: translateX(-50%) scale(1); }
  100% { opacity: 0.7; transform: translateX(-50%) scale(1.1); }
}

.hero__content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 720px;
  margin: 0 auto;
}

.hero__title {
  font-size: var(--fs-3xl);
  font-weight: 800;
  color: var(--color-heading);
  line-height: 1.15;
  margin-bottom: var(--spacing-md);
  letter-spacing: -0.02em;
}

.hero__accent {
  color: var(--color-accent);
}

.hero__subtitle {
  font-size: var(--fs-md);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xl);
  max-width: 560px;
  margin-left: auto;
  margin-right: auto;
}

.hero__actions {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm);
  align-items: center;
}

/* ============================
   SERVICES
   ============================ */
.services {
  padding: var(--spacing-3xl) 0;
}

.services__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.service-card {
  padding: var(--spacing-lg);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition), transform var(--transition);
}

.service-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
}

.service-card__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  margin-bottom: var(--spacing-sm);
  color: var(--color-accent);
  background-color: var(--color-accent-glow);
  border-radius: var(--radius-sm);
}

.service-card__title {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: var(--spacing-xs);
}

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

/* ============================
   ABOUT
   ============================ */
.about {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-bg-alt);
}

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

.about__intro {
  max-width: 540px;
}

.about__text {
  font-size: var(--fs-base);
  color: var(--color-text);
  margin-bottom: var(--spacing-sm);
  line-height: 1.8;
}

.about__text:last-child {
  margin-bottom: var(--spacing-md);
}

.about__region {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--fs-sm);
  color: var(--color-accent);
  padding-top: var(--spacing-xs);
}

.about__region-icon {
  flex-shrink: 0;
}

.about__values {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.about-value {
  display: flex;
  gap: var(--spacing-md);
  padding: var(--spacing-md);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: border-color var(--transition);
}

.about-value:hover {
  border-color: var(--color-accent);
}

.about-value__icon {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  color: var(--color-accent);
  background-color: var(--color-accent-glow);
  border-radius: var(--radius-sm);
}

.about-value__title {
  font-size: var(--fs-base);
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: 4px;
}

.about-value__text {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ============================
   WHY US
   ============================ */
.why {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-bg-alt);
}

.why__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--spacing-md);
}

.why-card {
  padding: var(--spacing-lg);
  border-left: 3px solid var(--color-accent);
  background-color: var(--color-surface);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
}

.why-card__number {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  font-weight: 700;
  color: var(--color-accent);
  margin-bottom: var(--spacing-xs);
}

.why-card__title {
  font-size: var(--fs-lg);
  font-weight: 600;
  color: var(--color-heading);
  margin-bottom: var(--spacing-xs);
}

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

/* ============================
   CONTACT
   ============================ */
.contact {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-bg-alt);
}

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

.contact__lead {
  font-size: var(--fs-md);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-lg);
}

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

.contact__detail {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}

.contact__detail a {
  color: var(--color-text-muted);
}

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

.contact__icon {
  flex-shrink: 0;
  color: var(--color-accent);
}

/* Form */
.contact-form {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md);
}

.contact-form__group {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-xs);
}

.contact-form__label {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text);
}

.contact-form__optional {
  color: var(--color-text-muted);
  font-weight: 400;
}

.contact-form__input {
  width: 100%;
  padding: 0.75rem 1rem;
  font-family: var(--font-family);
  font-size: var(--fs-base);
  color: var(--color-heading);
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.contact-form__input::placeholder {
  color: var(--color-text-muted);
  opacity: 0.5;
}

.contact-form__input:hover {
  border-color: var(--color-text-muted);
}

.contact-form__input:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px var(--color-accent-glow);
  outline: none;
}

.contact-form__input.is-error {
  border-color: var(--color-error);
}

/* Honeypot */
.contact-form__hp {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
}

/* Submit */
.contact-form__submit {
  margin-top: var(--spacing-xs);
}

.contact-form__submit:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* Status */
.contact-form__status {
  font-size: var(--fs-sm);
  min-height: 1.5em;
}

.contact-form__status.is-success {
  color: var(--color-success);
}

.contact-form__status.is-error {
  color: var(--color-error);
}

/* ============================
   FOOTER
   ============================ */
.footer {
  padding: var(--spacing-lg) 0;
  border-top: 1px solid var(--color-border);
}

.footer__inner {
  text-align: center;
}

.footer__copy {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

/* ============================
   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;
  }
}

/* ============================
   RESPONSIVE — Tablet (768px)
   ============================ */
@media (min-width: 768px) {
  .section__title {
    font-size: var(--fs-3xl);
  }

  .hero__title {
    font-size: var(--fs-4xl);
  }

  .hero__actions {
    flex-direction: row;
    justify-content: center;
  }

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

  .about__grid {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }

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

  .contact__inner {
    grid-template-columns: 1fr 1fr;
    align-items: start;
  }

  .header__menu {
    display: flex;
  }

  .header__burger {
    display: none;
  }
}

/* ============================
   O MNIE
   ============================ */
.about-me {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-bg);
}

.about-me__inner {
  display: flex;
  align-items: center;
  gap: var(--spacing-xl);
}

.about-me__avatar {
  flex-shrink: 0;
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: var(--color-surface);
  border: 2px solid var(--color-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 32px var(--color-accent-glow);
}

.about-me__initials {
  font-family: var(--font-mono);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--color-accent);
  letter-spacing: 0.05em;
}

.about-me__content .section__title {
  margin-bottom: var(--spacing-sm);
}

.about-me__text {
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: var(--spacing-sm);
}

.about-me__text:last-child {
  margin-bottom: 0;
}

@media (max-width: 600px) {
  .about-me__inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ============================
   OPINIE KLIENTÓW
   ============================ */
.testimonials {
  padding: var(--spacing-3xl) 0;
  background-color: var(--color-bg);
}

.testimonials .section__title {
  text-align: center;
  margin-bottom: var(--spacing-xl);
}

.testimonials__slider {
  position: relative;
  overflow: hidden;
}

.testimonials__track {
  display: flex;
  transition: transform 400ms ease;
}

.testimonial {
  flex: 0 0 100%;
  padding: 0 var(--spacing-sm);
}

.testimonial__quote {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--spacing-lg) var(--spacing-xl);
  position: relative;
  margin-bottom: var(--spacing-md);
}

.testimonial__mark {
  display: block;
  font-family: Georgia, serif;
  font-size: 4rem;
  line-height: 1;
  color: var(--color-accent);
  opacity: 0.4;
  margin-bottom: var(--spacing-xs);
  margin-top: -0.5rem;
}

.testimonial__text {
  color: var(--color-text);
  font-size: var(--fs-md);
  line-height: 1.7;
  font-style: italic;
}

.testimonial__author {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding-left: var(--spacing-sm);
}

.testimonial__name {
  font-weight: 600;
  color: var(--color-heading);
  font-size: var(--fs-base);
}

.testimonial__role {
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
}

.testimonials__controls {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.testimonials__btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text-muted);
  cursor: pointer;
  transition: var(--transition);
}

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

.testimonials__btn:disabled {
  opacity: 0.3;
  cursor: not-allowed;
}

.testimonials__dots {
  display: flex;
  gap: 0.5rem;
}

.testimonials__dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  border: none;
  background: var(--color-border);
  cursor: pointer;
  transition: var(--transition);
  padding: 0;
}

.testimonials__dot.is-active {
  background: var(--color-accent);
  transform: scale(1.3);
}

/* ============================
   RESPONSIVE — Desktop (1024px)
   ============================ */
@media (min-width: 1024px) {
  .services__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .why__grid {
    grid-template-columns: repeat(3, 1fr);
  }
}