/* ==========================================================================
   Happ Guide — дизайн-система (итерация 2).
   Tech / utility стиль: ясная иерархия, один акцентный цвет,
   светлая и тёмная тема, mobile-first.
   ========================================================================== */

/* ---------- Tokens ---------------------------------------------------- */
:root {
  /* Color — light */
  --color-bg: #ffffff;
  --color-bg-elevated: #f7f8fa;
  --color-bg-subtle: #eef1f5;
  --color-text: #14181f;
  --color-text-muted: #566072;
  --color-text-faint: #808a9c;
  --color-border: #e1e5eb;
  --color-border-strong: #ccd2dc;
  --color-primary: #2f6fed;
  --color-primary-hover: #2559c7;
  --color-primary-contrast: #ffffff;
  --color-primary-tint: #eaf1ff;
  --color-danger: #d43d4f;
  --color-success: #1c8a5a;
  --color-accent: #e07a1f;
  --color-accent-contrast: #ffffff;
  --color-accent-tint: #fdf0e2;

  /* Typography */
  --font-body: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-heading: "Manrope", "Inter", system-ui, -apple-system, sans-serif;
  --text-xs: 0.8125rem;
  --text-sm: 0.9375rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.375rem;
  --text-2xl: 1.75rem;
  --text-3xl: 2.25rem;
  --text-4xl: 2.75rem;
  --leading-tight: 1.2;
  --leading-normal: 1.6;

  /* Spacing scale */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 16px;
  --space-4: 24px;
  --space-5: 40px;
  --space-6: 64px;
  --space-7: 96px;

  /* Shape / elevation */
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --radius-pill: 999px;
  --shadow-sm: 0 1px 2px rgba(20, 24, 31, 0.06);
  --shadow-md: 0 8px 24px rgba(20, 24, 31, 0.08);
  --shadow-focus: 0 0 0 3px var(--color-primary-tint);

  /* Layout */
  --container-max: 1160px;
  --container-narrow: 760px;
  --header-height: 64px;
  --transition-fast: 150ms ease;
  --transition-base: 220ms ease;
}

[data-theme="dark"] {
  --color-bg: #0c0e12;
  --color-bg-elevated: #14171d;
  --color-bg-subtle: #1a1e26;
  --color-text: #edf0f5;
  --color-text-muted: #9aa3b5;
  --color-text-faint: #6d7688;
  --color-border: #262b34;
  --color-border-strong: #363d49;
  --color-primary: #6ea8ff;
  --color-primary-hover: #8fbcff;
  --color-primary-contrast: #0b1220;
  --color-primary-tint: #16233d;
  --color-danger: #ff6b7a;
  --color-success: #3fcf8e;
  --color-accent: #f5943a;
  --color-accent-contrast: #1a1002;
  --color-accent-tint: #2c1d0c;
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow-md: 0 12px 32px rgba(0, 0, 0, 0.45);
}

/* ---------- Reset ------------------------------------------------------ */
*, *::before, *::after { box-sizing: border-box; }
html { color-scheme: light dark; -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: var(--font-body);
  font-size: var(--text-base);
  background: var(--color-bg);
  color: var(--color-text);
  line-height: var(--leading-normal);
  transition: background-color var(--transition-base), color var(--transition-base);
}
img, svg { max-width: 100%; display: block; }
ul, ol { margin: 0; }
h1, h2, h3, h4 {
  font-family: var(--font-heading);
  line-height: var(--leading-tight);
  font-weight: 800;
  margin: 0 0 var(--space-2);
  letter-spacing: -0.01em;
}
h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-lg); }
p { margin: 0 0 var(--space-3); color: var(--color-text); }
a { color: var(--color-primary); text-decoration-thickness: 1.5px; text-underline-offset: 2px; }
a:hover { color: var(--color-primary-hover); }
strong { font-weight: 700; }

:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

::selection { background: var(--color-primary-tint); color: var(--color-text); }

.container {
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--space-3);
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ---------- Skip link ---------------------------------------------------- */
.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  padding: var(--space-2) var(--space-3);
  border-radius: 0 0 var(--radius-sm) 0;
  z-index: 200;
  font-weight: 600;
}
.skip-link:focus { left: 0; }

/* ---------- Header / navigation ------------------------------------------ */
.site-header {
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  background: color-mix(in srgb, var(--color-bg) 92%, transparent);
  backdrop-filter: blur(8px);
  z-index: 100;
}
.site-header__bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  min-height: var(--header-height);
}
.site-logo {
  font-family: var(--font-heading);
  font-weight: 800;
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--text-lg);
  letter-spacing: -0.01em;
  flex-shrink: 0;
}
.site-logo span { color: var(--color-primary); }

.main-nav__list {
  list-style: none;
  display: flex;
  gap: var(--space-4);
  margin: 0;
  padding: 0;
}
.main-nav__list a {
  text-decoration: none;
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: var(--text-sm);
  padding-block: var(--space-1);
  border-bottom: 2px solid transparent;
  transition: color var(--transition-fast), border-color var(--transition-fast);
}
.main-nav__list a:hover { color: var(--color-text); }
.main-nav__list a[aria-current="page"] { color: var(--color-primary); border-bottom-color: var(--color-primary); }

.header-actions { display: flex; align-items: center; gap: var(--space-2); flex-shrink: 0; }

.icon-btn, .theme-toggle, .burger {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-1);
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  border-radius: var(--radius-md);
  padding: var(--space-2);
  cursor: pointer;
  color: var(--color-text);
  line-height: 1;
  transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}
.icon-btn:hover, .theme-toggle:hover, .burger:hover { border-color: var(--color-border-strong); }
.icon-btn:active, .theme-toggle:active, .burger:active { transform: scale(0.94); }
.theme-toggle svg { width: 18px; height: 18px; }
.theme-toggle .icon-moon { display: none; }
[data-theme="dark"] .theme-toggle .icon-sun { display: none; }
[data-theme="dark"] .theme-toggle .icon-moon { display: block; }

.burger { display: none; width: 40px; height: 40px; }
.burger svg { width: 20px; height: 20px; }

/* ---------- Buttons ------------------------------------------------------ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  text-decoration: none;
  font-weight: 700;
  font-size: var(--text-sm);
  border: 1px solid transparent;
  cursor: pointer;
  transition: transform var(--transition-fast), background-color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  white-space: nowrap;
}
.btn:hover { transform: translateY(-1px); }
.btn:active { transform: translateY(0); }
.btn-primary { background: var(--color-primary); color: var(--color-primary-contrast); box-shadow: var(--shadow-sm); }
.btn-primary:hover { background: var(--color-primary-hover); color: var(--color-primary-contrast); }
.btn-secondary { background: transparent; border-color: var(--color-border-strong); color: var(--color-text); }
.btn-secondary:hover { border-color: var(--color-primary); color: var(--color-primary); }
.btn-accent { background: var(--color-accent); color: var(--color-accent-contrast); box-shadow: var(--shadow-sm); }
.btn-accent:hover { background: var(--color-accent); color: var(--color-accent-contrast); filter: brightness(1.08); }
.btn-lg { padding: var(--space-3) var(--space-5); font-size: var(--text-base); }
.btn-sm { padding: var(--space-1) var(--space-3); font-size: var(--text-xs); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

/* ---------- Breadcrumbs --------------------------------------------------- */
.breadcrumbs { padding-block: var(--space-2); font-size: var(--text-xs); color: var(--color-text-faint); }
.breadcrumbs ol { list-style: none; display: flex; flex-wrap: wrap; gap: var(--space-1); margin: 0; padding: 0; }
.breadcrumbs li:not(:last-child)::after { content: "/"; margin-left: var(--space-1); color: var(--color-text-faint); }
.breadcrumbs a { color: var(--color-text-faint); text-decoration: none; }
.breadcrumbs a:hover { color: var(--color-primary); }
.breadcrumbs li[aria-current="page"] { color: var(--color-text-muted); font-weight: 600; }

/* ---------- Hero ----------------------------------------------------------- */
.hero { padding-block: var(--space-6) var(--space-5); animation: fade-up 500ms ease both; }
.hero h1 { max-width: 22ch; }
.hero__lead { color: var(--color-text-muted); max-width: 60ch; font-size: var(--text-lg); }
.hero__cta-group { display: flex; flex-wrap: wrap; gap: var(--space-2); margin-top: var(--space-4); }

@keyframes fade-up {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ---------- Sections --------------------------------------------------- */
.section { padding-block: var(--space-5); border-top: 1px solid var(--color-border); }
.section__title { margin-bottom: var(--space-3); }
.section > p:first-of-type { color: var(--color-text-muted); }

/* ---------- Cards -------------------------------------------------------- */
.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: var(--space-3); }
.card {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  background: var(--color-bg-elevated);
  text-decoration: none;
  color: inherit;
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  transition: border-color var(--transition-fast), transform var(--transition-fast), box-shadow var(--transition-fast);
}
a.card:hover { border-color: var(--color-primary); transform: translateY(-2px); box-shadow: var(--shadow-md); }
.card h3 { margin: 0; font-size: var(--text-base); }
.card p { margin: 0; color: var(--color-text-muted); font-size: var(--text-sm); }
.card-icon {
  width: 40px;
  height: 40px;
  padding: var(--space-2);
  border-radius: var(--radius-md);
  background: var(--color-primary-tint);
  color: var(--color-primary);
}
.card-cta { margin-top: auto; font-weight: 700; font-size: var(--text-sm); color: var(--color-primary); }

/* ---------- Steps ---------------------------------------------------------- */
.steps { list-style: none; padding: 0; counter-reset: step; display: flex; flex-direction: column; gap: var(--space-3); }
.steps li {
  counter-increment: step;
  position: relative;
  padding-left: 44px;
}
.steps li::before {
  content: counter(step);
  position: absolute;
  left: 0;
  top: 0;
  width: 30px;
  height: 30px;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: var(--text-sm);
}

/* ---------- Tables (comparisons) -------------------------------------------- */
.table-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }
.compare-table { width: 100%; border-collapse: collapse; min-width: 480px; }
.compare-table th, .compare-table td {
  border: 1px solid var(--color-border);
  padding: var(--space-2) var(--space-3);
  text-align: left;
  font-size: var(--text-sm);
}
.compare-table th { background: var(--color-bg-subtle); font-family: var(--font-heading); }
.compare-table tbody tr:hover { background: var(--color-bg-elevated); }

@media (max-width: 640px) {
  .compare-table { min-width: 0; }
  .compare-table thead { display: none; }
  .compare-table, .compare-table tbody, .compare-table tr, .compare-table td { display: block; width: 100%; }
  .compare-table tr { border: 1px solid var(--color-border); border-radius: var(--radius-md); margin-bottom: var(--space-2); overflow: hidden; }
  .compare-table td { border: none; border-bottom: 1px solid var(--color-border); }
  .compare-table td:last-child { border-bottom: none; }
  .compare-table td::before { content: attr(data-label); display: block; font-weight: 700; font-size: var(--text-xs); color: var(--color-text-faint); margin-bottom: 2px; }
}

/* ---------- FAQ / details ------------------------------------------------- */
.faq-item {
  border-bottom: 1px solid var(--color-border);
  padding-block: var(--space-3);
}
.faq-item summary {
  cursor: pointer;
  font-weight: 700;
  font-size: var(--text-base);
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "";
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  background: currentColor;
  color: var(--color-text-faint);
  -webkit-mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6 9l6 6 6-6' stroke='black' stroke-width='2' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat;
  mask: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath d='M6 9l6 6 6-6' stroke='black' stroke-width='2' fill='none' stroke-linecap='round' stroke-linejoin='round'/%3E%3C/svg%3E") center / contain no-repeat;
  transition: transform var(--transition-base);
}
.faq-item[open] summary::after { transform: rotate(180deg); }
.faq-item p { margin-top: var(--space-2); color: var(--color-text-muted); animation: fade-up 200ms ease both; }

/* ---------- Notice / callout ------------------------------------------------ */
.notice {
  border: 1px solid var(--color-border);
  border-left: 4px solid var(--color-primary);
  background: var(--color-bg-elevated);
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-md);
}
.notice p:last-child { margin-bottom: 0; }

/* ---------- Related links --------------------------------------------------- */
.related-list { list-style: none; padding: 0; display: flex; flex-wrap: wrap; gap: var(--space-2); }
.related-list a {
  display: inline-flex;
  align-items: center;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-pill);
  padding: var(--space-2) var(--space-4);
  text-decoration: none;
  color: var(--color-text);
  font-size: var(--text-sm);
  font-weight: 600;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}
.related-list a:hover { border-color: var(--color-primary); color: var(--color-primary); }

/* ---------- Filters (catalog) ----------------------------------------------- */
.filter-bar { display: flex; gap: var(--space-2); flex-wrap: wrap; margin-bottom: var(--space-4); }
.filter-bar button {
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  border-radius: var(--radius-pill);
  padding: var(--space-2) var(--space-4);
  cursor: pointer;
  color: var(--color-text-muted);
  font-weight: 600;
  font-size: var(--text-sm);
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast);
}
.filter-bar button:hover { border-color: var(--color-primary); }
.filter-bar button[aria-pressed="true"] { background: var(--color-primary); color: var(--color-primary-contrast); border-color: var(--color-primary); }

/* ---------- Forms ------------------------------------------------------------ */
label { display: block; font-weight: 600; font-size: var(--text-sm); margin-bottom: var(--space-3); }
input, textarea {
  width: 100%;
  margin-top: var(--space-1);
  padding: var(--space-2) var(--space-3);
  border: 1px solid var(--color-border-strong);
  border-radius: var(--radius-md);
  background: var(--color-bg-elevated);
  color: var(--color-text);
  font: inherit;
}
input:focus, textarea:focus { outline: none; border-color: var(--color-primary); box-shadow: var(--shadow-focus); }

/* ---------- Footer ------------------------------------------------------------ */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding-block: var(--space-5);
  margin-top: var(--space-6);
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}
.footer-grid { display: flex; flex-wrap: wrap; gap: var(--space-5); justify-content: space-between; }
.footer-grid nav strong { color: var(--color-text); font-family: var(--font-heading); }
.footer-grid nav ul { list-style: none; padding: 0; margin: var(--space-2) 0 0; display: flex; flex-direction: column; gap: var(--space-1); }
.footer-grid a { color: var(--color-text-muted); text-decoration: none; }
.footer-grid a:hover { color: var(--color-primary); }
.site-footer p { color: var(--color-text-faint); font-size: var(--text-xs); max-width: 60ch; }

/* ---------- Mobile navigation ------------------------------------------------- */
@media (max-width: 767px) {
  .burger { display: inline-flex; }
  .main-nav {
    position: fixed;
    inset: var(--header-height) 0 0 0;
    background: var(--color-bg);
    display: none;
    overflow-y: auto;
    padding: var(--space-4) var(--space-3);
  }
  .main-nav.is-open { display: block; animation: fade-up 200ms ease both; }
  .main-nav__list { flex-direction: column; gap: var(--space-1); }
  .main-nav__list a { display: block; padding: var(--space-3); font-size: var(--text-lg); border-bottom: 1px solid var(--color-border); }
  .main-nav__list a[aria-current="page"] { border-bottom: 1px solid var(--color-border); background: var(--color-bg-elevated); border-radius: var(--radius-md); }
  .header-actions .btn-sm { padding: var(--space-2) var(--space-3); }
  h1 { font-size: var(--text-3xl); }
  .hero { padding-block: var(--space-5) var(--space-4); }
}

@media (min-width: 768px) {
  .main-nav { display: block !important; }
  .burger { display: none !important; }
}

/* ---------- Larger screens ------------------------------------------------------ */
@media (min-width: 1024px) {
  h1 { font-size: var(--text-4xl); }
  .hero__lead { font-size: var(--text-xl); }
}

/* ---------- Pricing plans ------------------------------------------------------ */
.plans-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: var(--space-4);
  align-items: stretch;
}
.plan-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  background: var(--color-bg-elevated);
  position: relative;
}
.plan-card--featured {
  border: 2px solid var(--color-accent);
  box-shadow: 0 0 0 4px var(--color-accent-tint);
}
.plan-badge {
  display: inline-flex;
  align-self: flex-start;
  align-items: center;
  gap: 4px;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-pill);
  border: 1px solid var(--color-border-strong);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-text-muted);
}
.plan-badge--featured {
  border-color: var(--color-accent);
  color: var(--color-accent);
  background: var(--color-accent-tint);
}
.plan-name { font-size: var(--text-lg); font-family: var(--font-heading); font-weight: 800; margin: 0; }
.plan-price { display: flex; align-items: baseline; gap: 6px; }
.plan-price__value { font-family: var(--font-heading); font-size: var(--text-3xl); font-weight: 800; line-height: 1; }
.plan-price__unit { font-size: var(--text-sm); color: var(--color-text-muted); }
.plan-sub { font-size: var(--text-sm); color: var(--color-text-muted); margin: -6px 0 0; }
.plan-save {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--color-success);
  background: color-mix(in srgb, var(--color-success) 14%, transparent);
  padding: 2px var(--space-2);
  border-radius: var(--radius-pill);
  width: fit-content;
}
.plan-features { list-style: none; padding: 0; margin: 0; display: flex; flex-direction: column; gap: var(--space-2); flex: 1; }
.plan-features li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-2);
  font-size: var(--text-sm);
  padding-block: var(--space-1);
  border-bottom: 1px solid var(--color-border);
}
.plan-features li:last-child { border-bottom: none; }
.plan-features li::before {
  content: "✓";
  color: var(--color-success);
  font-weight: 700;
  flex-shrink: 0;
}
.plan-cta { width: 100%; justify-content: center; text-align: center; }

/* Quiz / plan finder */
.plan-quiz {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  background: var(--color-bg-subtle);
  margin-bottom: var(--space-4);
}
.plan-quiz__question { font-weight: 700; margin-bottom: var(--space-3); }
.plan-quiz__options { display: flex; flex-wrap: wrap; gap: var(--space-2); }
.plan-quiz__options button {
  border: 1px solid var(--color-border-strong);
  background: var(--color-bg-elevated);
  color: var(--color-text);
  border-radius: var(--radius-pill);
  padding: var(--space-2) var(--space-4);
  font-weight: 600;
  font-size: var(--text-sm);
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}
.plan-quiz__options button:hover { border-color: var(--color-primary); }
.plan-quiz__options button[aria-pressed="true"] { background: var(--color-primary); border-color: var(--color-primary); color: var(--color-primary-contrast); }
.plan-quiz__result { margin: var(--space-3) 0 0; font-size: var(--text-sm); color: var(--color-text-muted); min-height: 1.5em; }
.plan-quiz__result strong { color: var(--color-text); }

.plan-card.is-recommended {
  animation: plan-pulse 900ms ease 2;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 4px var(--color-primary-tint);
}
@keyframes plan-pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.02); }
}