/*
 * Btor Oy — Public Site Stylesheet
 * Style: Nordic minimalism — light, clean, lots of whitespace.
 * Typography: Inter (Google Fonts) with system-font fallback stack.
 */

/* =====================================================================
   0. CSS Custom Properties (design tokens)
   ===================================================================== */
:root {
  /* Palette */
  --color-bg:          #f8f8f6;
  --color-surface:     #ffffff;
  --color-border:      #e4e4e0;
  --color-accent:      #1a73e8;
  --color-accent-dark: #1558b0;
  --color-text:        #1a1a1a;
  --color-text-muted:  #6b6b6b;
  --color-footer-bg:   #1a1a1a;
  --color-footer-text: #d4d4d0;

  /* Spacing scale */
  --space-xs:  0.5rem;
  --space-sm:  1rem;
  --space-md:  2rem;
  --space-lg:  4rem;
  --space-xl:  6rem;

  /* Typography */
  --font-base: 'Inter', system-ui, -apple-system, BlinkMacSystemFont,
               'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-size-sm:   0.875rem;
  --font-size-base: 1rem;
  --font-size-lg:   1.125rem;
  --font-size-xl:   1.5rem;
  --font-size-2xl:  2rem;
  --font-size-3xl:  2.75rem;
  --line-height:    1.7;

  /* Layout */
  --max-width: 1100px;
  --radius:    6px;
  --shadow:    0 2px 12px rgba(0, 0, 0, 0.07);

  /* Transitions */
  --transition: 0.2s ease;
}

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

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

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

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

a:hover,
a:focus-visible {
  color: var(--color-accent-dark);
  text-decoration: underline;
}

ul,
ol {
  list-style: none;
}

/* =====================================================================
   2. Utility Classes
   ===================================================================== */
.container {
  width: 100%;
  max-width: var(--max-width);
  margin-inline: auto;
  padding-inline: var(--space-md);
}

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

/* =====================================================================
   3. Header & Navigation
   ===================================================================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  box-shadow: var(--shadow);
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--space-sm);
}

/* Logo / brand */
.site-logo {
  font-size: var(--font-size-xl);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
  text-decoration: none;
}

.site-logo:hover,
.site-logo:focus-visible {
  color: var(--color-accent);
  text-decoration: none;
}

/* Desktop navigation */
.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-md);
}

.site-nav a {
  font-size: var(--font-size-sm);
  font-weight: 500;
  letter-spacing: 0.02em;
  color: var(--color-text-muted);
  text-transform: uppercase;
  text-decoration: none;
  padding-block: var(--space-xs);
  border-bottom: 2px solid transparent;
  transition: color var(--transition), border-color var(--transition);
}

.site-nav a:hover,
.site-nav a:focus-visible,
.site-nav a[aria-current="page"] {
  color: var(--color-accent);
  border-bottom-color: var(--color-accent);
  text-decoration: none;
}

/* Hamburger button (mobile) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: space-around;
  width: 2rem;
  height: 1.5rem;
  background: transparent;
  border: none;
  cursor: pointer;
  padding: 0;
  gap: 5px;
}

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

/* Hamburger → X animation */
.nav-toggle[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* =====================================================================
   4. Hero Section
   ===================================================================== */
.hero {
  padding-block: var(--space-xl);
  background-color: var(--color-surface);
  text-align: center;
}

.hero__eyebrow {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-sm);
}

.hero__title {
  font-size: clamp(2rem, 5vw, var(--font-size-3xl));
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.15;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  max-width: 750px;
  margin-inline: auto;
}

.hero__subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  margin-inline: auto;
  margin-bottom: var(--space-lg);
}

/* CTA buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.75rem;
  border-radius: var(--radius);
  font-size: var(--font-size-base);
  font-weight: 600;
  cursor: pointer;
  transition: background-color var(--transition), color var(--transition),
              box-shadow var(--transition);
  text-decoration: none;
  border: 2px solid transparent;
}

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

.btn--primary:hover,
.btn--primary:focus-visible {
  background-color: var(--color-accent-dark);
  border-color: var(--color-accent-dark);
  color: #fff;
  text-decoration: none;
  box-shadow: 0 4px 16px rgba(26, 115, 232, 0.3);
}

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

.btn--outline:hover,
.btn--outline:focus-visible {
  background-color: var(--color-accent);
  color: #fff;
  text-decoration: none;
}

.hero__actions {
  display: flex;
  gap: var(--space-sm);
  justify-content: center;
  flex-wrap: wrap;
}

/* =====================================================================
   5. Section Shared Styles
   ===================================================================== */
.section {
  padding-block: var(--space-lg);
}

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

.section__header {
  text-align: center;
  margin-bottom: var(--space-lg);
}

.section__label {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.section__title {
  font-size: clamp(1.5rem, 3vw, var(--font-size-2xl));
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.2;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.section__desc {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 600px;
  margin-inline: auto;
}

/* =====================================================================
   6. Features / Value-Props (index.html)
   ===================================================================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: var(--space-md);
}

.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition);
}

.feature-card:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

.feature-card__icon {
  font-size: 2rem;
  margin-bottom: var(--space-sm);
}

.feature-card__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}

.feature-card__text {
  color: var(--color-text-muted);
  font-size: var(--font-size-base);
}

/* =====================================================================
   7. About Page
   ===================================================================== */
.about-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  align-items: start;
}

.about-text p {
  color: var(--color-text-muted);
  margin-bottom: var(--space-sm);
}

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

.about-meta {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  box-shadow: var(--shadow);
}

.about-meta__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.about-meta__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.about-meta__item {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.about-meta__label {
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
}

.about-meta__value {
  font-size: var(--font-size-base);
  font-weight: 500;
  color: var(--color-text);
}

/* Values list */
.values-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: var(--space-md);
}

.value-item {
  padding: var(--space-md);
  background: var(--color-surface);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--radius) var(--radius) 0;
  box-shadow: var(--shadow);
}

.value-item__title {
  font-size: var(--font-size-lg);
  font-weight: 600;
  margin-bottom: var(--space-xs);
  color: var(--color-text);
}

.value-item__text {
  color: var(--color-text-muted);
}

/* =====================================================================
   8. Services Page
   ===================================================================== */
.services-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--space-md);
}

.service-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
  transition: box-shadow var(--transition), transform var(--transition);
}

.service-card:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.1);
  transform: translateY(-2px);
}

.service-card__icon {
  font-size: 2.5rem;
  margin-bottom: var(--space-xs);
}

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

.service-card__desc {
  color: var(--color-text-muted);
  flex: 1;
}

.service-card__tag {
  display: inline-block;
  margin-top: var(--space-xs);
  padding: 0.2rem 0.65rem;
  background-color: #e8f0fe;
  color: var(--color-accent);
  border-radius: 999px;
  font-size: var(--font-size-sm);
  font-weight: 600;
}

/* =====================================================================
   9. Contact Page
   ===================================================================== */
.contact-layout {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: var(--space-lg);
  align-items: start;
}

.contact-info__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.contact-info__list {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.contact-info__item {
  display: flex;
  gap: var(--space-sm);
  align-items: flex-start;
}

.contact-info__icon {
  font-size: 1.25rem;
  flex-shrink: 0;
  margin-top: 2px;
}

.contact-info__detail strong {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: 2px;
}

/* Contact form */
.contact-form {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  box-shadow: var(--shadow);
}

.contact-form__title {
  font-size: var(--font-size-xl);
  font-weight: 700;
  margin-bottom: var(--space-md);
  color: var(--color-text);
}

.form-group {
  margin-bottom: var(--space-md);
}

.form-group label {
  display: block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 0.625rem 0.875rem;
  font-family: var(--font-base);
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
  outline: none;
  resize: vertical;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.15);
}

.form-group input.error,
.form-group select.error,
.form-group textarea.error {
  border-color: #d93025;
  box-shadow: 0 0 0 3px rgba(217, 48, 37, 0.1);
}

.form-error {
  display: block;
  margin-top: 4px;
  font-size: var(--font-size-sm);
  color: #d93025;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-sm);
}

.form-success {
  display: none;
  padding: var(--space-sm) var(--space-md);
  background-color: #e6f4ea;
  color: #137333;
  border: 1px solid #b7dfbf;
  border-radius: var(--radius);
  margin-bottom: var(--space-md);
  font-weight: 500;
}

/* =====================================================================
   10. Page Hero (inner pages)
   ===================================================================== */
.page-hero {
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  padding-block: var(--space-lg);
  text-align: center;
}

.page-hero__label {
  display: inline-block;
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: var(--space-xs);
}

.page-hero__title {
  font-size: clamp(1.75rem, 4vw, var(--font-size-2xl));
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.page-hero__subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-muted);
  max-width: 580px;
  margin-inline: auto;
}

/* =====================================================================
   11. Footer
   ===================================================================== */
.site-footer {
  background-color: var(--color-footer-bg);
  color: var(--color-footer-text);
  padding-block: var(--space-lg);
}

.site-footer .container {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: var(--space-lg);
  padding-bottom: var(--space-lg);
  border-bottom: 1px solid #333;
}

.footer-brand__name {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: #fff;
  margin-bottom: var(--space-xs);
}

.footer-brand__tagline {
  font-size: var(--font-size-sm);
  color: #9a9a96;
  max-width: 220px;
}

.footer-col__title {
  font-size: var(--font-size-sm);
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: var(--space-sm);
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: var(--space-xs);
}

.footer-col ul li a {
  font-size: var(--font-size-sm);
  color: var(--color-footer-text);
  text-decoration: none;
  transition: color var(--transition);
}

.footer-col ul li a:hover,
.footer-col ul li a:focus-visible {
  color: #fff;
  text-decoration: none;
}

.footer-col address {
  font-style: normal;
  font-size: var(--font-size-sm);
  color: var(--color-footer-text);
  line-height: var(--line-height);
}

.site-footer__bottom {
  padding-top: var(--space-md);
}

.site-footer__bottom .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: var(--space-sm);
  /* Reset inner container grid */
  grid-template-columns: none;
  border-bottom: none;
  padding-bottom: 0;
}

.footer-legal {
  font-size: var(--font-size-sm);
  color: #9a9a96;
}

.footer-business-id {
  font-size: var(--font-size-sm);
  color: #9a9a96;
}

/* =====================================================================
   12. Responsive — Tablet
   ===================================================================== */
@media (max-width: 900px) {
  .about-layout,
  .contact-layout {
    grid-template-columns: 1fr;
  }

  .site-footer .container {
    grid-template-columns: 1fr 1fr;
  }
}

/* =====================================================================
   13. Responsive — Mobile
   ===================================================================== */
@media (max-width: 640px) {
  :root {
    --space-lg: 3rem;
    --space-xl: 4rem;
  }

  /* Show hamburger, hide inline nav */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    flex-direction: column;
    align-items: flex-start;
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--space-sm) var(--space-md);
    gap: var(--space-sm);
    /* Hide by default */
    display: none;
  }

  .site-nav.is-open {
    display: flex;
  }

  .site-nav a {
    font-size: var(--font-size-base);
    padding-block: var(--space-xs);
    border-bottom: none;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .site-footer .container {
    grid-template-columns: 1fr;
    gap: var(--space-md);
  }

  .site-footer__bottom .container {
    flex-direction: column;
    align-items: flex-start;
  }
}

/* =====================================================================
   14. Focus styles (accessibility)
   ===================================================================== */
:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 3px;
}

/* =====================================================================
   15. Print
   ===================================================================== */
@media print {
  .site-header,
  .nav-toggle,
  .hero__actions,
  .site-footer {
    display: none;
  }
}