/* Trace S.r.l. — Main Stylesheet */

/* ==========================================================================
   1. Reset CSS
   ========================================================================== */

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

html {
  scroll-behavior: smooth;
}

body {
  min-height: 100vh;
  text-rendering: optimizeSpeed;
}

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

input, button, textarea, select {
  font: inherit;
}

ul {
  list-style: none;
}

/* ==========================================================================
   2. Custom Properties
   ========================================================================== */

:root {
  --color-primary: #4B2D8E;
  --color-primary-light: #5E3FA6;
  --color-accent: #E8891A;
  --color-accent-hover: #D07510;
  --color-text: #1e293b;
  --color-text-light: #64748b;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-border: #e2e8f0;

  --section-padding: clamp(60px, 8vw, 120px);
  --container-max: 1200px;
  --container-padding: clamp(16px, 4vw, 32px);

  --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-size-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
  --font-size-sm: clamp(0.875rem, 0.85rem + 0.15vw, 0.9375rem);
  --font-size-lg: clamp(1.125rem, 1rem + 0.5vw, 1.25rem);
  --font-size-h1: clamp(2rem, 1.5rem + 2.5vw, 3.25rem);
  --font-size-h2: clamp(1.75rem, 1.25rem + 2vw, 2.5rem);
  --font-size-h3: clamp(1.25rem, 1.1rem + 0.75vw, 1.5rem);
  --line-height: 1.6;

  --transition-fast: 150ms ease;
  --transition-base: 300ms ease;

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);

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

/* ==========================================================================
   3. Tipografia
   ========================================================================== */

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

h1 {
  font-size: var(--font-size-h1);
  font-weight: 700;
  line-height: 1.15;
}

h2 {
  font-size: var(--font-size-h2);
  font-weight: 700;
  line-height: 1.2;
}

h3 {
  font-size: var(--font-size-h3);
  font-weight: 600;
  line-height: 1.3;
}

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

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

/* ==========================================================================
   4. Container e Layout base
   ========================================================================== */

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

section {
  padding-block: var(--section-padding);
}

section:nth-child(even) {
  background-color: var(--color-bg-alt);
}

main section > .container > h2 {
  text-align: center;
}

.section-intro {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  margin-top: 0.75rem;
  max-width: 65ch;
  margin-left: auto;
  margin-right: auto;
  text-align: center;
}

/* ==========================================================================
   5. Bottoni
   ========================================================================== */

.btn {
  display: inline-block;
  padding: 12px 28px;
  border-radius: var(--radius-sm);
  font-weight: 600;
  font-size: var(--font-size-base);
  cursor: pointer;
  border: 2px solid transparent;
  transition: background-color var(--transition-fast), color var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
  text-align: center;
}

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

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  color: #ffffff;
  box-shadow: var(--shadow-md);
}

.btn-secondary {
  background-color: transparent;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

.btn-secondary:hover {
  background-color: var(--color-primary);
  color: #ffffff;
  box-shadow: var(--shadow-md);
}

/* ==========================================================================
   6. Focus States (accessibilità)
   ========================================================================== */

:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* ==========================================================================
   7. Header e Navigazione
   ========================================================================== */

body {
  padding-top: 72px;
}

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast), padding var(--transition-base);
}

.site-header.scrolled {
  border-bottom-color: var(--color-border);
  box-shadow: var(--shadow-sm);
}

.site-header nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--container-padding);
  padding-block: 16px;
  transition: padding-block var(--transition-base);
}

.site-header.scrolled nav {
  padding-block: 10px;
}

.logo {
  font-weight: 700;
  font-size: 1.25rem;
  color: var(--color-primary);
  flex-shrink: 0;
}

.logo:hover {
  color: var(--color-primary-light);
}

.nav-links {
  display: none;
  gap: 32px;
  list-style: none;
  margin-inline-start: auto;
  margin-inline-end: 2rem;
}

.nav-links a {
  position: relative;
  color: var(--color-text);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.02em;
  transition: color var(--transition-fast);
}

.nav-links a::after {
  content: '';
  position: absolute;
  bottom: -3px;
  left: 0;
  right: 0;
  height: 2px;
  background-color: var(--color-accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--transition-base);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-accent);
}

.nav-links a:hover::after,
.nav-links a.active::after {
  transform: scaleX(1);
}

.header-cta {
  display: none;
  flex-shrink: 0;
  font-weight: 600;
  color: var(--color-accent);
  font-size: var(--font-size-sm);
}

.menu-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 4px;
}

.menu-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text);
  border-radius: 2px;
  transition: transform var(--transition-base), opacity var(--transition-base);
}

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

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

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

/* Mobile nav — full-screen overlay */
.mobile-nav {
  position: fixed;
  inset: 0;
  background-color: rgba(255, 255, 255, 0.98);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 32px;
  z-index: 999;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-base);
}

.mobile-nav.is-open {
  opacity: 1;
  pointer-events: auto;
}

.mobile-nav ul {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 32px;
  list-style: none;
}

.mobile-nav a {
  color: var(--color-text);
  font-weight: 600;
  font-size: 1.5rem;
  transition: color var(--transition-fast);
}

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

/* ==========================================================================
   8. Hero
   ========================================================================== */

#hero {
  background-color: var(--color-primary);
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(13, 148, 136, 0.15) 0%, transparent 60%),
    radial-gradient(ellipse at 80% 20%, rgba(13, 148, 136, 0.10) 0%, transparent 50%);
  color: #ffffff;
  padding-block: clamp(80px, 12vw, 160px);
  text-align: center;
}

.hero-content {
  max-width: 800px;
  margin-inline: auto;
}

#hero h1 {
  color: #ffffff;
  margin-bottom: 24px;
}

.hero-subtitle {
  font-size: var(--font-size-lg);
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 40px;
  line-height: 1.7;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
}

#hero .btn-secondary {
  color: #ffffff;
  border-color: rgba(255, 255, 255, 0.5);
}

#hero .btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.15);
  border-color: #ffffff;
  color: #ffffff;
}

/* ==========================================================================
   9. Servizi
   ========================================================================== */

#servizi h2,
#servizi .section-intro {
  margin-bottom: 0.5rem;
}

/* Alias — works alongside .section-intro */
.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--color-text-light);
  margin-top: 0.75rem;
  max-width: 65ch;
}

.services-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 2.5rem;
}

@media (min-width: 768px) {
  .services-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .services-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.service-card {
  background-color: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: clamp(24px, 3vw, 32px);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.service-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.service-card .card-icon {
  width: 48px;
  height: 48px;
  flex-shrink: 0;
  color: var(--color-accent);
}

.service-card h3 {
  color: var(--color-primary);
}

.service-card ul {
  list-style: none;
  padding-inline-start: 0;
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  flex: 1;
}

.service-card ul li {
  position: relative;
  padding-inline-start: 1.5rem;
}

.service-card ul li::before {
  content: "✓";
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 600;
}

.card-price {
  font-weight: 600;
  color: var(--color-accent);
  font-size: var(--font-size-sm);
}

.card-cta {
  display: inline-flex;
  align-items: center;
  font-weight: 600;
  font-size: var(--font-size-sm);
  color: var(--color-accent);
  margin-top: auto;
  transition: color var(--transition-fast);
}

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

/* ==========================================================================
   10. Perché Trace
   ========================================================================== */

#perche-trace {
  background-color: var(--color-bg-alt);
}

.advantages-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  margin-top: 2.5rem;
}

@media (min-width: 768px) {
  .advantages-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .advantages-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}

.advantage-card {
  background-color: var(--color-bg);
  border-radius: var(--radius-md);
  padding: clamp(32px, 4vw, 48px);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  text-align: center;
  box-shadow: var(--shadow-sm);
  transition: box-shadow var(--transition-base), transform var(--transition-base);
}

.advantage-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
}

.advantage-card .card-icon {
  width: 56px;
  height: 56px;
  flex-shrink: 0;
  color: var(--color-accent);
  margin-inline: auto;
}

.advantage-card h3 {
  color: var(--color-primary);
}

.advantage-card p {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

/* ==========================================================================
   11. Clienti
   ========================================================================== */

#clienti {
  text-align: center;
}

#clienti h2 {
  margin-bottom: 0.5rem;
}

.clients-logos {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  align-items: center;
  gap: clamp(24px, 4vw, 48px);
  margin-top: 2.5rem;
  align-items: center;
  justify-content: center;
}

.clients-logos img {
  max-height: 48px;
  filter: grayscale(100%);
  opacity: 0.6;
  transition: filter var(--transition-base), opacity var(--transition-base);
}

.clients-logos img:hover {
  filter: grayscale(0%);
  opacity: 1;
}

.client-placeholder {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-light);
  opacity: 0.5;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  padding: 16px 32px;
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  display: inline-block;
  transition: opacity var(--transition-base), color var(--transition-base), border-color var(--transition-base);
}

.client-placeholder:hover {
  opacity: 1;
  color: var(--color-primary);
  border-color: var(--color-primary);
}

/* ==========================================================================
   12. Partner
   ========================================================================== */

#partner {
  background-color: var(--color-primary);
  color: #ffffff;
}

#partner h2 {
  color: #ffffff;
}

.partner-content {
  max-width: 720px;
}

.partner-intro {
  margin-top: 1rem;
  color: rgba(255, 255, 255, 0.85);
  font-size: var(--font-size-lg);
  line-height: 1.7;
}

.partner-benefits {
  list-style: none;
  padding-inline-start: 0;
  margin-top: 1.5rem;
  margin-bottom: 2rem;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  color: #ffffff;
}

.partner-benefits li {
  padding-left: 28px;
  position: relative;
}

.partner-benefits li::before {
  content: '\2713';
  position: absolute;
  left: 0;
  color: var(--color-accent);
  font-weight: 700;
}

/* ==========================================================================
   13. Contatti
   ========================================================================== */

.contact-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  margin-top: 1.75rem;
}

@media (min-width: 768px) {
  .contact-layout {
    grid-template-columns: 3fr 2fr;
  }
}

/* Form */
#contact-form {
  display: flex;
  flex-direction: column;
  gap: 0.85rem;
}

.form-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.85rem;
}

@media (min-width: 768px) {
  .form-row {
    grid-template-columns: 1fr 1fr;
  }
}

.form-note {
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
  margin-top: 0.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.form-group label {
  font-weight: 500;
  font-size: var(--font-size-sm);
  color: var(--color-text);
}

.form-group input,
.form-group select,
.form-group textarea {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  font-size: var(--font-size-base);
  color: var(--color-text);
  background-color: var(--color-bg);
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.15);
}

.form-group textarea {
  resize: vertical;
  min-height: 90px;
}

.form-group--checkbox {
  flex-direction: row;
  align-items: flex-start;
  gap: 0.6rem;
}

.form-group--checkbox input[type="checkbox"] {
  width: 18px;
  height: 18px;
  flex-shrink: 0;
  margin-top: 2px;
  accent-color: var(--color-accent);
  cursor: pointer;
}

.form-group--checkbox label {
  font-size: var(--font-size-sm);
  font-weight: 400;
}

/* Contact info */
.contact-info {
  background-color: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: clamp(24px, 3vw, 32px);
  align-self: start;
}

.contact-info h3 {
  color: var(--color-primary);
  font-size: var(--font-size-lg);
  margin-bottom: 1rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--color-accent);
}

.contact-info address {
  font-style: normal;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  font-size: var(--font-size-sm);
}

.contact-info address p {
  padding-left: 0.75rem;
  border-left: 3px solid transparent;
  transition: border-color var(--transition-fast);
}

.contact-info address p:hover {
  border-left-color: var(--color-accent);
}

.contact-info address p strong {
  display: block;
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-accent);
  margin-bottom: 0.35rem;
  font-weight: 600;
}

.contact-info address a {
  color: var(--color-primary);
  font-weight: 500;
}

.contact-info address a:hover {
  color: var(--color-accent);
}

.contact-meta {
  margin-top: 1.5rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  font-size: var(--font-size-sm);
  color: var(--color-text-light);
}

/* ==========================================================================
   14. Footer
   ========================================================================== */

#footer {
  background-color: var(--color-primary);
  color: rgba(255, 255, 255, 0.8);
  padding-block: clamp(48px, 6vw, 80px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 2fr 1fr 1fr 1fr;
  }
}

.footer-logo {
  display: inline-block;
  font-weight: 700;
  font-size: var(--font-size-lg);
  color: #ffffff;
  margin-bottom: 1rem;
}

.footer-logo:hover {
  color: rgba(255, 255, 255, 0.85);
}

.footer-col p {
  font-size: var(--font-size-sm);
  line-height: var(--line-height);
}

.footer-col h4 {
  font-size: var(--font-size-base);
  font-weight: 600;
  color: #ffffff;
  margin-bottom: 1rem;
}

.footer-col ul {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.footer-col ul a {
  color: rgba(255, 255, 255, 0.75);
  font-size: var(--font-size-sm);
  transition: color var(--transition-fast);
}

.footer-col ul a:hover {
  color: #ffffff;
}

.footer-col address {
  font-style: normal;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  font-size: var(--font-size-sm);
}

.footer-col address a {
  color: rgba(255, 255, 255, 0.75);
}

.footer-col address a:hover {
  color: #ffffff;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid rgba(255, 255, 255, 0.15);
  font-size: var(--font-size-sm);
  color: rgba(255, 255, 255, 0.6);
}

.footer-bottom nav {
  display: flex;
  gap: 1.5rem;
}

.footer-bottom nav a {
  color: rgba(255, 255, 255, 0.6);
  transition: color var(--transition-fast);
}

.footer-bottom nav a:hover {
  color: #ffffff;
}

/* ==========================================================================
   15. Privacy Page
   ========================================================================== */

.privacy-page {
  padding-block: 48px 80px;
  max-width: 800px;
}

.privacy-page h1 {
  margin-bottom: 8px;
}

.privacy-updated {
  color: var(--color-text-light);
  font-size: var(--font-size-sm);
}

.privacy-page h2 {
  font-size: var(--font-size-h3);
  margin-top: 40px;
  margin-bottom: 12px;
}

.privacy-page address {
  font-style: normal;
  line-height: var(--line-height);
  color: var(--color-text-light);
}

.privacy-page ul {
  list-style: disc;
  padding-inline-start: 1.5rem;
  margin-top: 0.75rem;
  margin-bottom: 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
  color: var(--color-text-light);
}

.privacy-page p {
  margin-top: 0.75rem;
}

/* ==========================================================================
   16. Responsive — Mobile
   ========================================================================== */

@media (max-width: 767px) {
  .nav-links {
    display: none;
  }

  .menu-toggle {
    display: flex;
  }
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }

  .menu-toggle {
    display: none;
  }
}

@media (min-width: 1024px) {
  .header-cta {
    display: inline-flex;
  }
}

/* ==========================================================================
   17. Scroll animations (Task 14)
   ========================================================================== */

.fade-up {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}
.fade-up.visible {
  opacity: 1;
  transform: translateY(0);
}
/* Stagger */
.fade-up:nth-child(2) { transition-delay: 0.1s; }
.fade-up:nth-child(3) { transition-delay: 0.2s; }
.fade-up:nth-child(4) { transition-delay: 0.3s; }

@media (prefers-reduced-motion: reduce) {
  .fade-up {
    opacity: 1;
    transform: none;
    transition: none;
  }
}

/* ==========================================================================
   18. Form validation styles (Task 15)
   ========================================================================== */

.error-message { color: #dc2626; font-size: 0.8125rem; margin-top: 4px; }
.form-group.error input,
.form-group.error select,
.form-group.error textarea { border-color: #dc2626; }
.form-error-global { color: #dc2626; margin-top: 16px; }
.form-success { text-align: center; padding: 48px; }
.form-success h3 { color: var(--color-accent); margin-bottom: 12px; }