/* ============================================================
   DTraining — Design System CSS
   Palette monocromatica | Font Inter (self-hosted) | Griglia 8px
   ============================================================ */

/* --- Self-hosted Inter font (GDPR compliant) --- */
@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 400;
  font-display: swap;
  src: url('/fonts/inter-400.woff2') format('woff2'),
       url('/fonts/inter-400.ttf') format('truetype');
}

@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 500;
  font-display: swap;
  src: url('/fonts/inter-500.woff2') format('woff2'),
       url('/fonts/inter-500.ttf') format('truetype');
}

@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 600;
  font-display: swap;
  src: url('/fonts/inter-600.woff2') format('woff2'),
       url('/fonts/inter-600.ttf') format('truetype');
}

@font-face {
  font-family: 'Inter';
  font-style: normal;
  font-weight: 700;
  font-display: swap;
  src: url('/fonts/inter-700.woff2') format('woff2'),
       url('/fonts/inter-700.ttf') format('truetype');
}

/* --- CSS Custom Properties --- */
:root {
  /* Palette */
  --color-bg:          #FFFFFF;
  --color-bg-alt:      #F5F5F5;
  --color-border:      #949494;  /* AAA: 3:1 on white for non-text elements */
  --color-border-light:#E0E0E0;  /* decorative borders only */
  --color-heading:     #1A1A1A;
  --color-body:        #333333;
  --color-secondary:   #525252;  /* AAA: ~7.5:1 on white */
  --color-btn-hover:   #000000;

  /* Typography */
  --font-family:       'Inter', system-ui, -apple-system, sans-serif;
  --fs-h1:             3rem;      /* 48px */
  --fs-h2:             2rem;      /* 32px */
  --fs-h3:             1.375rem;  /* 22px */
  --fs-body:           1.125rem;  /* 18px */
  --fs-small:          1rem;      /* 16px */
  --fs-xs:             0.875rem;  /* 14px */
  --lh-body:           1.7;

  /* Spacing — griglia 8px */
  --space-xs:          8px;
  --space-sm:          16px;
  --space-md:          24px;
  --space-lg:          32px;
  --space-xl:          48px;
  --space-section:     64px;

  /* Layout */
  --max-text:          720px;
  --max-layout:        1120px;

  /* Focus */
  --focus-outline:     2px solid var(--color-heading);
  --focus-offset:      2px;
}

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

html {
  font-size: 100%;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-family);
  font-size: var(--fs-body);
  font-weight: 400;
  line-height: var(--lh-body);
  color: var(--color-body);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --- Accessibility — Skip Link --- */
.skip-link {
  position: absolute;
  left: -9999px;
  top: auto;
  width: 1px;
  height: 1px;
  overflow: hidden;
  z-index: 100000;
}

.skip-link:focus {
  position: fixed;
  top: 0;
  left: 0;
  width: auto;
  height: auto;
  padding: 12px 24px;
  background: var(--color-heading);
  color: var(--color-bg);
  font-size: var(--fs-body);
  font-weight: 600;
  text-decoration: none;
  z-index: 100000;
}

/* Screen reader only */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* --- Focus Visible --- */
:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

:focus:not(:focus-visible) {
  outline: none;
}

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

/* --- Typography --- */
h1, h2, h3 {
  color: var(--color-heading);
  line-height: 1.2;
  max-width: var(--max-text);
}

h1 {
  font-size: var(--fs-h1);
  font-weight: 700;
  margin-bottom: var(--space-lg);
}

h2 {
  font-size: var(--fs-h2);
  font-weight: 600;
  margin-bottom: var(--space-md);
}

h3 {
  font-size: var(--fs-h3);
  font-weight: 600;
  margin-bottom: var(--space-sm);
}

p {
  margin-bottom: var(--space-md);
  max-width: var(--max-text);
}

small, .text-small {
  font-size: var(--fs-small);
  color: var(--color-secondary);
}

/* --- Links --- */
a {
  color: var(--color-heading);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}

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

/* Navigation-style link with arrow */
.link-arrow {
  text-decoration: none;
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: 4px;
}

.link-arrow::after {
  content: '\2192';
  display: inline-block;
  transition: transform 0.2s ease;
}

.link-arrow:hover::after {
  transform: translateX(4px);
}

/* --- Layout --- */
.container {
  width: 100%;
  max-width: var(--max-layout);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-section) 0;
}

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

.text-center {
  text-align: center;
}

.text-center h1,
.text-center h2,
.text-center p {
  margin-left: auto;
  margin-right: auto;
}

/* --- Header / Navigation --- */
.site-header {
  border-bottom: 1px solid var(--color-border-light);
  background: var(--color-bg);
  position: sticky;
  top: 0;
  z-index: 1000;
}

.site-header .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 88px;
}

.site-logo {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.site-logo img {
  height: 64px;
  width: auto;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
}

.site-nav a {
  text-decoration: none;
  font-size: var(--fs-small);
  font-weight: 500;
  color: var(--color-body);
  padding: 8px 4px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  position: relative;
}

.site-nav a:hover,
.site-nav a[aria-current="page"] {
  color: var(--color-heading);
}

.site-nav a[aria-current="page"]::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--color-heading);
}

/* Hamburger menu button */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  min-height: 44px;
  min-width: 44px;
  align-items: center;
  justify-content: center;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-heading);
  position: relative;
  transition: background 0.2s ease;
}

.nav-toggle span::before,
.nav-toggle span::after {
  content: '';
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-heading);
  position: absolute;
  transition: transform 0.2s ease;
}

.nav-toggle span::before {
  top: -7px;
}

.nav-toggle span::after {
  top: 7px;
}

/* Open state */
.nav-toggle[aria-expanded="true"] span {
  background: transparent;
}

.nav-toggle[aria-expanded="true"] span::before {
  top: 0;
  transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] span::after {
  top: 0;
  transform: rotate(-45deg);
}

/* --- Buttons --- */
.btn {
  display: inline-block;
  background-color: var(--color-heading);
  color: var(--color-bg);
  font-family: var(--font-family);
  font-size: var(--fs-small);
  font-weight: 600;
  padding: 16px 32px;
  border: 2px solid var(--color-heading);
  border-radius: 0;
  cursor: pointer;
  text-decoration: none;
  text-align: center;
  min-height: 48px;
  transition: background-color 0.2s ease, color 0.2s ease;
  line-height: 1;
}

.btn:hover {
  background-color: var(--color-btn-hover);
  border-color: var(--color-btn-hover);
  color: var(--color-bg);
}

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

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

.btn--outline:hover {
  background-color: var(--color-heading);
  color: var(--color-bg);
}

/* --- Cards --- */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-lg);
}

.card {
  border: 1px solid var(--color-border);
  padding: var(--space-lg);
  transition: border-color 0.2s ease;
  text-decoration: none;
  display: block;
  color: inherit;
}

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

.card h3 {
  margin-bottom: var(--space-sm);
}

.card p {
  margin-bottom: var(--space-sm);
  color: var(--color-body);
}

.card .link-arrow {
  font-size: var(--fs-small);
}

/* --- Blockquote / Citazioni --- */
blockquote {
  border-left: 3px solid var(--color-heading);
  padding-left: var(--space-md);
  margin: var(--space-lg) 0;
  max-width: var(--max-text);
  font-style: normal;
}

blockquote p {
  margin-bottom: var(--space-sm);
}

blockquote p:last-child {
  margin-bottom: 0;
}

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

.form-group label {
  display: block;
  font-weight: 500;
  margin-bottom: var(--space-xs);
  color: var(--color-heading);
  font-size: var(--fs-small);
}

.form-group input,
.form-group textarea {
  width: 100%;
  font-family: var(--font-family);
  font-size: var(--fs-body);
  padding: 12px 16px;
  border: 1px solid var(--color-border);
  border-radius: 0;
  background: var(--color-bg);
  color: var(--color-body);
  transition: border-color 0.2s ease;
  line-height: var(--lh-body);
}

.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--color-heading);
  border-width: 2px;
  padding: 11px 15px; /* compensate for 2px border */
}

.form-group input:focus-visible,
.form-group textarea:focus-visible {
  outline: var(--focus-outline);
  outline-offset: var(--focus-offset);
}

.form-group input[aria-invalid="true"],
.form-group textarea[aria-invalid="true"] {
  border-color: var(--color-heading);
  border-width: 2px;
  padding: 11px 15px;
}

.form-group textarea {
  min-height: 150px;
  resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--color-secondary);
}

.form-group .field-error {
  font-size: var(--fs-xs);
  color: var(--color-heading);
  font-weight: 500;
  margin-top: var(--space-xs);
}

/* Checkbox / consent */
.form-check {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  margin-bottom: var(--space-md);
}

.form-check input[type="checkbox"] {
  width: 24px;
  height: 24px;
  min-width: 24px;
  margin-top: 2px;
  accent-color: var(--color-heading);
  cursor: pointer;
}

.form-check label {
  font-size: var(--fs-small);
  color: var(--color-body);
  cursor: pointer;
  line-height: 1.5;
}

.form-status {
  padding: var(--space-sm);
  margin-top: var(--space-sm);
  font-weight: 500;
}

.form-status--success {
  border: 1px solid var(--color-heading);
  color: var(--color-heading);
}

.form-status--error {
  border: 1px solid var(--color-heading);
  color: var(--color-heading);
}

/* Required field indicator */
.form-required {
  font-size: var(--fs-small);
  color: var(--color-secondary);
  margin-bottom: var(--space-md);
}

/* --- Numbered List (metodo) --- */
.method-list {
  list-style: none;
  counter-reset: method;
  max-width: var(--max-text);
}

.method-list li {
  counter-increment: method;
  margin-bottom: var(--space-md);
  padding-left: var(--space-xl);
  position: relative;
}

.method-list li::before {
  content: counter(method) ".";
  position: absolute;
  left: 0;
  font-weight: 700;
  font-size: var(--fs-h3);
  color: var(--color-heading);
  line-height: 1.7;
}

.method-list li strong {
  color: var(--color-heading);
}

/* --- Services section --- */
.service-block {
  margin-bottom: var(--space-section);
}

.service-block:last-child {
  margin-bottom: 0;
}

.service-block h2 {
  scroll-margin-top: 88px; /* header height + padding */
}

.service-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-xs);
  margin-top: var(--space-sm);
  max-width: var(--max-text);
}

.service-tag {
  font-size: var(--fs-xs);
  padding: 4px 12px;
  border: 1px solid var(--color-border);
  color: var(--color-secondary);
  white-space: nowrap;
}

/* --- Footer --- */
.site-footer {
  border-top: 1px solid var(--color-border-light);
  padding: var(--space-xl) 0 var(--space-lg);
  font-size: var(--fs-small);
  color: var(--color-secondary);
}

.footer-content {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-lg);
}

.footer-info p {
  margin-bottom: var(--space-xs);
  max-width: none;
}

.footer-links {
  display: flex;
  gap: var(--space-md);
}

.footer-links a {
  color: var(--color-secondary);
  font-size: var(--fs-small);
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.footer-bottom {
  margin-top: var(--space-lg);
  padding-top: var(--space-sm);
  border-top: 1px solid var(--color-border-light);
  font-size: var(--fs-xs);
  color: var(--color-secondary);
}

/* --- Hero --- */
.hero {
  padding: 96px 0;
  text-align: center;
}

.hero h1 {
  margin-left: auto;
  margin-right: auto;
}

.hero p {
  margin-left: auto;
  margin-right: auto;
  font-size: var(--fs-body);
  color: var(--color-body);
}

/* --- Page header (inner pages) --- */
.page-header {
  padding: var(--space-section) 0 var(--space-lg);
}

/* --- Breadcrumb --- */
.breadcrumb {
  padding-top: var(--space-sm);
}

.breadcrumb ol {
  list-style: none;
  display: flex;
  gap: 8px;
  font-size: var(--fs-small);
  color: var(--color-secondary);
}

.breadcrumb li + li::before {
  content: '/';
  margin-right: 8px;
}

/* --- Form wrapper --- */
.form-wrapper {
  max-width: var(--max-text);
  margin: 0 auto;
}

.form-alt-contact {
  margin-top: var(--space-md);
}

/* --- Contact info block --- */
.contact-info {
  margin-top: var(--space-lg);
}

.contact-info p {
  margin-bottom: var(--space-xs);
}

/* ============================================================
   RESPONSIVE — Mobile
   ============================================================ */
@media (max-width: 768px) {
  :root {
    --fs-h1:     2rem;      /* 32px */
    --fs-h2:     1.5rem;    /* 24px */
    --fs-h3:     1.125rem;  /* 18px */
    --fs-body:   1rem;      /* 16px */
    --fs-small:  0.875rem;  /* 14px */
    --fs-xs:     0.75rem;   /* 12px */
    --space-section: 48px;
  }

  .container {
    padding: 0 var(--space-sm);
  }

  /* Mobile navigation */
  .nav-toggle {
    display: flex;
  }

  .site-nav {
    display: none;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border-light);
    flex-direction: column;
    padding: var(--space-sm);
    gap: 0;
  }

  .site-nav[data-open="true"] {
    display: flex;
  }

  .site-nav a {
    padding: 12px var(--space-sm);
    display: flex;
    min-height: 44px;
    align-items: center;
  }

  /* Cards stack */
  .cards-grid {
    grid-template-columns: 1fr;
  }

  /* Hero */
  .hero {
    padding: 64px 0 48px;
  }

  /* Footer */
  .footer-content {
    flex-direction: column;
  }

  .footer-links {
    flex-direction: column;
    gap: var(--space-sm);
  }
}

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

  body {
    font-size: 12pt;
    color: #000;
    background: #fff;
  }

  a {
    color: #000;
    text-decoration: underline;
  }

  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 10pt;
  }
}