/* =====================================================
   BMI Kalkulačka — shared stylesheet
   Sections: variables → reset → layout → components → utilities → responsive → accessibility
   ===================================================== */

/* -----------------------------------------------------
   1. VARIABLES (design system — locked, see BLUEPRINT.md §5)
   ----------------------------------------------------- */
:root {
  /* Colors */
  --color-primary: #0E9F8E;
  --color-primary-dark: #0B7E71;
  --color-secondary: #2B3A42;
  --color-accent: #F2994A;
  --color-bg: #FBFAF7;
  --color-surface: #FFFFFF;
  --color-border: #E4E1DA;
  --color-text: #2B3A42;
  --color-text-muted: #5B6A71;

  /* BMI category colors */
  --color-underweight: #4FA8E0;
  --color-normal: #2FAE66;
  --color-overweight: #F2A93B;
  --color-obese: #E0563D;

  /* Typography */
  --font-display: 'Poppins', sans-serif;
  --font-body: 'Inter', sans-serif;

  --fs-sm: 14px;
  --fs-base: 16px;
  --fs-md: 18px;
  --fs-lg: 22px;
  --fs-xl: 28px;
  --fs-2xl: 36px;
  --fs-3xl: 48px;

  --fw-regular: 400;
  --fw-medium: 500;
  --fw-semibold: 600;
  --fw-bold: 700;

  --lh-tight: 1.2;
  --lh-base: 1.6;
  --ls-tight: -0.01em;

  /* Spacing scale — ONLY these values used for padding/margin */
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --sp-7: 48px;
  --sp-8: 64px;
  --sp-9: 96px;

  /* Radius / shadow */
  --radius-sm: 8px;
  --radius-md: 16px;
  --radius-lg: 24px;
  --shadow-card: 0 2px 12px rgba(43, 58, 66, 0.08);
  --shadow-card-hover: 0 6px 20px rgba(43, 58, 66, 0.12);

  /* Layout */
  --container-max: 1200px;

  /* Motion */
  --transition-base: 150ms ease-out;
}

/* -----------------------------------------------------
   2. RESET
   ----------------------------------------------------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: var(--lh-base);
  -webkit-font-smoothing: antialiased;
}
h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--sp-4);
  font-family: var(--font-display);
  font-weight: var(--fw-semibold);
  line-height: var(--lh-tight);
  letter-spacing: var(--ls-tight);
  color: var(--color-secondary);
}
h1 { font-size: var(--fs-3xl); font-weight: var(--fw-bold); }
h2 { font-size: var(--fs-2xl); }
h3 { font-size: var(--fs-xl); }
h4 { font-size: var(--fs-lg); }
p { margin: 0 0 var(--sp-4); }
a { color: var(--color-primary-dark); text-decoration-thickness: 1.5px; }
a:hover { color: var(--color-primary); }
img { max-width: 100%; height: auto; display: block; }
ul, ol { margin: 0 0 var(--sp-4); padding-left: var(--sp-5); }
button, input, select, textarea { font-family: inherit; font-size: inherit; }
table { border-collapse: collapse; width: 100%; }

/* -----------------------------------------------------
   3. LAYOUT
   ----------------------------------------------------- */
.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--sp-5);
}
.section { padding-block: var(--sp-8); }
.grid { display: grid; gap: var(--sp-5); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.stack { display: flex; flex-direction: column; }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: var(--sp-3); }

/* -----------------------------------------------------
   4. COMPONENTS
   ----------------------------------------------------- */

/* Skip link */
.skip-link {
  position: absolute;
  left: var(--sp-3);
  top: -60px;
  background: var(--color-primary);
  color: #fff;
  padding: var(--sp-2) var(--sp-4);
  border-radius: var(--radius-sm);
  z-index: 1000;
  transition: top var(--transition-base);
}
.skip-link:focus { top: var(--sp-3); color: #fff; }

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
}
.site-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding-block: var(--sp-3);
}
.site-header__logo {
  font-family: var(--font-display);
  font-weight: var(--fw-bold);
  font-size: var(--fs-md);
  color: var(--color-secondary);
  text-decoration: none;
}
.site-nav__list {
  display: flex;
  align-items: center;
  gap: var(--sp-5);
  list-style: none;
  margin: 0;
  padding: 0;
}
.site-nav__list a {
  color: var(--color-secondary);
  text-decoration: none;
  font-weight: var(--fw-medium);
  padding-block: var(--sp-2);
  border-bottom: 2px solid transparent;
  transition: border-color var(--transition-base), color var(--transition-base);
}
.site-nav__list a:hover,
.site-nav__list a[aria-current="page"] {
  color: var(--color-primary-dark);
  border-bottom-color: var(--color-primary);
}
.site-nav__dropdown { position: relative; }
.site-nav__submenu {
  position: absolute;
  top: 100%;
  left: 0;
  min-width: 220px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  box-shadow: var(--shadow-card);
  list-style: none;
  margin: 0;
  padding: var(--sp-2);
  display: none;
  flex-direction: column;
  gap: var(--sp-1);
}
.site-nav__dropdown:hover .site-nav__submenu,
.site-nav__dropdown:focus-within .site-nav__submenu { display: flex; }
.site-nav__submenu a { display: block; padding: var(--sp-2) var(--sp-3); border-radius: var(--radius-sm); border-bottom: none; }
.site-nav__submenu a:hover { background: var(--color-bg); }

.menu-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--sp-2);
  min-width: 44px;
  min-height: 44px;
}
.menu-toggle__bar {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-secondary);
  margin: 5px auto;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

/* Footer */
.site-footer {
  background: var(--color-secondary);
  color: #E8ECEE;
  padding-block: var(--sp-8) var(--sp-6);
  margin-top: var(--sp-9);
}
.site-footer a { color: #E8ECEE; text-decoration: none; }
.site-footer a:hover { color: var(--color-accent); }
.site-footer__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-6);
  margin-bottom: var(--sp-6);
}
.site-footer__heading {
  color: #fff;
  font-size: var(--fs-base);
  margin-bottom: var(--sp-3);
}
.site-footer__list { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: var(--sp-2); }
.site-footer__bottom {
  border-top: 1px solid rgba(255,255,255,0.15);
  padding-top: var(--sp-5);
  font-size: var(--fs-sm);
  color: #B7C0C4;
}

/* Breadcrumb */
.breadcrumb {
  padding-block: var(--sp-4);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}
.breadcrumb ol { list-style: none; padding: 0; margin: 0; display: flex; flex-wrap: wrap; gap: var(--sp-1); }
.breadcrumb li:not(:last-child)::after { content: "/"; margin-left: var(--sp-1); color: var(--color-border); }
.breadcrumb a { color: var(--color-text-muted); text-decoration: none; }
.breadcrumb a:hover { color: var(--color-primary-dark); }
.breadcrumb [aria-current="page"] { color: var(--color-text); font-weight: var(--fw-medium); }

/* Hero */
.hero { padding-block: var(--sp-8); text-align: center; }
.hero__subhead { font-size: var(--fs-md); color: var(--color-text-muted); max-width: 640px; margin-inline: auto; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: var(--sp-3) var(--sp-5);
  border-radius: var(--radius-md);
  font-weight: var(--fw-semibold);
  text-decoration: none;
  cursor: pointer;
  border: 2px solid transparent;
  min-height: 44px;
  transition: background var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}
.btn--primary { background: var(--color-primary); color: #fff; }
.btn--primary:hover { background: var(--color-primary-dark); color: #fff; }
.btn--secondary { background: transparent; border-color: var(--color-secondary); color: var(--color-secondary); }
.btn--secondary:hover { background: var(--color-secondary); color: #fff; }

/* CTA section */
.cta {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--sp-7);
  text-align: center;
}
.cta__actions { display: flex; gap: var(--sp-4); justify-content: center; flex-wrap: wrap; margin-top: var(--sp-5); }

/* Cards */
.card {
  background: var(--color-surface);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: var(--sp-5);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}
.card:hover { box-shadow: var(--shadow-card-hover); transform: translateY(-2px); }
.card__icon { width: 48px; height: 48px; margin-bottom: var(--sp-3); }
.card__title { margin-bottom: var(--sp-2); }

/* FAQ */
.faq { margin-block: var(--sp-6); }
.faq__item {
  border-bottom: 1px solid var(--color-border);
  padding-block: var(--sp-4);
}
.faq__item summary {
  cursor: pointer;
  font-weight: var(--fw-semibold);
  font-family: var(--font-display);
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary::after { content: "+"; font-size: var(--fs-lg); color: var(--color-primary); }
.faq__item[open] summary::after { content: "\2212"; }
.faq__item p { margin-top: var(--sp-3); color: var(--color-text-muted); }

/* Calculator form */
.calculator {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  padding: var(--sp-6);
  max-width: 560px;
  margin-inline: auto;
}
.calculator__field { margin-bottom: var(--sp-4); text-align: left; }
.calculator__field label {
  display: block;
  font-weight: var(--fw-medium);
  margin-bottom: var(--sp-2);
}
.calculator__field input,
.calculator__field select {
  width: 100%;
  min-height: 44px;
  padding: var(--sp-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  background: var(--color-bg);
}
.calculator__field input:focus,
.calculator__field select:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 1px;
}
.calculator__result {
  margin-top: var(--sp-5);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--color-border);
  text-align: center;
}
.calculator__unit-toggle {
  display: flex;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
}
.calculator__unit-toggle label {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-weight: var(--fw-medium);
  transition: background var(--transition-base), border-color var(--transition-base), color var(--transition-base);
}
.calculator__unit-toggle input {
  position: absolute;
  opacity: 0;
  width: 1px;
  height: 1px;
}
.calculator__unit-toggle input:checked + label,
.calculator__unit-toggle label:has(input:checked) {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: #fff;
}
.calculator__unit-toggle input:focus-visible + label {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}
.calculator__field-row { display: flex; gap: var(--sp-3); }
.calculator__field-row .calculator__field { flex: 1; }
.calculator__error {
  color: var(--color-obese);
  font-size: var(--fs-sm);
  font-weight: var(--fw-medium);
  margin-top: var(--sp-3);
}

/* BMI gauge */
.bmi-gauge { max-width: 280px; margin-inline: auto; }
.bmi-gauge__value {
  font-family: var(--font-display);
  font-size: var(--fs-3xl);
  font-weight: var(--fw-bold);
  color: var(--color-secondary);
}
.bmi-gauge__category {
  display: inline-block;
  margin-top: var(--sp-2);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius-sm);
  font-weight: var(--fw-semibold);
  font-size: var(--fs-sm);
}
.bmi-gauge__category--underweight { background: color-mix(in srgb, var(--color-underweight) 18%, white); color: var(--color-underweight); }
.bmi-gauge__category--normal { background: color-mix(in srgb, var(--color-normal) 18%, white); color: var(--color-normal); }
.bmi-gauge__category--overweight { background: color-mix(in srgb, var(--color-overweight) 18%, white); color: var(--color-overweight); }
.bmi-gauge__category--obese { background: color-mix(in srgb, var(--color-obese) 18%, white); color: var(--color-obese); }

.bmi-gauge__bar {
  position: relative;
  margin-top: var(--sp-5);
  height: 16px;
  border-radius: var(--radius-sm);
  background: linear-gradient(
    to right,
    var(--color-underweight) 0% 24%,
    var(--color-normal) 24% 43%,
    var(--color-overweight) 43% 57%,
    var(--color-obese) 57% 100%
  );
}
.bmi-gauge__bar--percentile {
  background: linear-gradient(
    to right,
    var(--color-underweight) 0% 5%,
    var(--color-normal) 5% 85%,
    var(--color-overweight) 85% 95%,
    var(--color-obese) 95% 100%
  );
}
.bmi-gauge__pointer {
  position: absolute;
  top: -10px;
  width: 0;
  height: 0;
  border-left: 8px solid transparent;
  border-right: 8px solid transparent;
  border-top: 12px solid var(--color-secondary);
  transform: translateX(-50%);
  transition: left 300ms ease-out;
}
.bmi-gauge__scale {
  display: flex;
  justify-content: space-between;
  margin-top: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}

/* BMI category table */
.bmi-table th, .bmi-table td {
  padding: var(--sp-3) var(--sp-4);
  border-bottom: 1px solid var(--color-border);
  text-align: left;
}
.bmi-table th { font-family: var(--font-display); color: var(--color-text-muted); font-size: var(--fs-sm); text-transform: uppercase; letter-spacing: 0.04em; }
.bmi-table td:first-child { font-weight: var(--fw-medium); }

/* Trust block */
.trust-block {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  background: color-mix(in srgb, var(--color-primary) 8%, white);
  border: 1px solid color-mix(in srgb, var(--color-primary) 25%, white);
  border-radius: var(--radius-md);
  padding: var(--sp-4);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-block: var(--sp-5);
}

/* Ad slot */
.ad-slot {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-border);
  color: var(--color-text-muted);
  font-size: var(--fs-sm);
  border-radius: var(--radius-sm);
  margin-inline: auto;
}
.ad-slot--in-content { width: 300px; height: 250px; margin-block: var(--sp-6); }
.ad-slot--sidebar { width: 300px; height: 600px; }

/* -----------------------------------------------------
   5. UTILITIES
   ----------------------------------------------------- */
.text-center { text-align: center; }
.text-muted { color: var(--color-text-muted); }
.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}
.mt-5 { margin-top: var(--sp-5); }
.mt-6 { margin-top: var(--sp-6); }
.mb-0 { margin-bottom: 0; }

/* -----------------------------------------------------
   6. RESPONSIVE (tablet 768px, mobile below)
   ----------------------------------------------------- */
@media (max-width: 768px) {
  .grid-2, .grid-3, .site-footer__grid { grid-template-columns: 1fr; }
  .site-nav--desktop { display: none; }
  .menu-toggle { display: block; }
  h1 { font-size: var(--fs-2xl); }
  h2 { font-size: var(--fs-xl); }
  .ad-slot--sidebar { width: 100%; height: 250px; }
}

.site-nav--mobile { display: none; border-top: 1px solid var(--color-border); }
.site-nav--mobile:not([hidden]) { display: block; }
.site-nav--mobile ul { gap: var(--sp-3); }
.site-nav--mobile a { padding-block: var(--sp-2); display: inline-block; }

@media (max-width: 480px) {
  .ad-slot--in-content { width: 100%; }
}

/* -----------------------------------------------------
   7. ACCESSIBILITY
   ----------------------------------------------------- */
:focus-visible {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
  html { scroll-behavior: auto; }
}