/* ==========================================================================
   AIDO — styles.css
   Pure CSS, no framework. Mobile-first with dark/light theme.
   ========================================================================== */

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

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

body {
  min-height: 100vh;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

img {
  height: auto;
}

a {
  color: inherit;
  text-decoration: none;
}

ul {
  list-style: none;
}

button {
  background: none;
  border: none;
  cursor: pointer;
  font: inherit;
  color: inherit;
}

/* --- Design Tokens --- */
:root {
  /* Colors — Light theme */
  --color-primary: #1A91CF;
  --color-primary-dark: #1578AB;
  --color-primary-light: #E0F2FE;
  --color-accent: #1A91CF;
  --color-accent-hover: #1578AB;

  --bg-primary: #FFFFFF;
  --bg-secondary: #F3F4F6;
  --bg-tertiary: #E5E7EB;
  --text-primary: #1E1E1E;
  --text-secondary: #4B5563;
  --text-muted: #9CA3AF;
  --card-bg: #FFFFFF;
  --card-border: rgba(0, 0, 0, 0.06);
  --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.1), 0 4px 10px rgba(0, 0, 0, 0.06);
  --header-bg: rgba(255, 255, 255, 0.95);
  --header-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --hero-overlay: linear-gradient(135deg, rgba(255, 255, 255, 0.85), rgba(255, 255, 255, 0.75));
  --hero-text: #1E1E1E;
  --hero-text-sub: #4B5563;
  --contact-overlay: linear-gradient(135deg, rgba(26, 145, 207, 0.8), rgba(21, 120, 171, 0.85));
  --footer-bg: #111827;
  --footer-text: #9CA3AF;
  --process-line: #E5E7EB;
  --process-number: #1A91CF;

  /* Typography */
  --font-heading: 'Poppins', system-ui, -apple-system, sans-serif;
  --font-body: 'Raleway', system-ui, -apple-system, sans-serif;

  /* Spacing */
  --space-xs: 0.5rem;
  --space-sm: 1rem;
  --space-md: 1.5rem;
  --space-lg: 3rem;
  --space-xl: 5rem;
  --space-2xl: 7.5rem;

  /* Layout */
  --max-width: 1200px;
  --header-height: 72px;
  --radius: 12px;
  --radius-sm: 8px;

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s ease;
}

/* --- Dark Theme --- */
@media (prefers-color-scheme: dark) {
  :root {
    --bg-primary: #111827;
    --bg-secondary: #1F2937;
    --bg-tertiary: #374151;
    --text-primary: #F9FAFB;
    --text-secondary: #D1D5DB;
    --text-muted: #6B7280;
    --card-bg: #1F2937;
    --card-border: rgba(255, 255, 255, 0.06);
    --card-shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
    --card-shadow-hover: 0 10px 25px rgba(0, 0, 0, 0.4), 0 4px 10px rgba(0, 0, 0, 0.25);
    --header-bg: rgba(17, 24, 39, 0.95);
    --header-shadow: 0 1px 3px rgba(0, 0, 0, 0.4);
    --hero-overlay: linear-gradient(135deg, rgba(0, 0, 0, 0.75), rgba(0, 0, 0, 0.55));
    --hero-text: #FFFFFF;
    --hero-text-sub: rgba(255, 255, 255, 0.9);
    --contact-overlay: linear-gradient(135deg, rgba(17, 24, 39, 0.92), rgba(21, 120, 171, 0.85));
    --footer-bg: #0B0F19;
    --footer-text: #6B7280;
    --process-line: #374151;
    --process-number: #60A5FA;
    --color-primary-light: #1E3A5F;
  }
}

/* --- Typography --- */
body {
  font-family: var(--font-body);
  font-size: clamp(0.95rem, 1.2vw, 1.125rem);
  color: var(--text-primary);
  background-color: var(--bg-primary);
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

h1, h2, h3 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
}

.section-title {
  font-size: clamp(1.5rem, 3.5vw, 2.5rem);
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

.section-title--light {
  color: #FFFFFF;
}

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

.skip-link {
  position: absolute;
  top: -100%;
  left: var(--space-sm);
  background: var(--color-primary);
  color: #fff;
  padding: var(--space-xs) var(--space-sm);
  border-radius: var(--radius-sm);
  z-index: 1000;
  font-weight: 600;
}

.skip-link:focus {
  top: var(--space-xs);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 0.85em 2em;
  font-family: var(--font-heading);
  font-weight: 600;
  font-size: 1rem;
  border-radius: var(--radius-sm);
  transition: transform var(--transition-fast), box-shadow var(--transition-fast), background-color var(--transition-fast);
  cursor: pointer;
  border: none;
}

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

.btn--primary:hover,
.btn--primary:focus-visible {
  background-color: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 12px rgba(26, 145, 207, 0.4);
}

/* --- Animations --- */
.fade-in {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

/* --- Header --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: var(--header-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  z-index: 100;
  transition: box-shadow var(--transition-normal), background var(--transition-normal);
}

.header--scrolled {
  box-shadow: var(--header-shadow);
}

.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 100%;
}

.header__logo img {
  height: 27px;
  width: auto;
}

/* Logo theme swap — show/hide based on color scheme */
.header__logo .logo-dark {
  display: none;
}

@media (prefers-color-scheme: dark) {
  .header__logo .logo-light {
    display: none;
  }
  .header__logo .logo-dark {
    display: block;
  }
}

.header__nav-list {
  display: flex;
  gap: var(--space-md);
}

.header__nav-link {
  font-family: var(--font-heading);
  font-weight: 500;
  font-size: 0.9rem;
  color: var(--text-secondary);
  padding: var(--space-xs) 0;
  position: relative;
  transition: color var(--transition-fast);
}

.header__nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--color-primary);
  transition: width var(--transition-normal);
}

.header__nav-link:hover,
.header__nav-link:focus-visible {
  color: var(--color-primary);
}

.header__nav-link:hover::after,
.header__nav-link:focus-visible::after {
  width: 100%;
}

.header__burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  padding: 10px;
}

.header__burger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: transform var(--transition-normal), opacity var(--transition-fast);
}

/* Burger open state */
.header__burger[aria-expanded="true"] span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

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

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

/* --- Hero --- */
.hero {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  min-height: 100dvh;
  padding: calc(var(--header-height) + var(--space-lg)) var(--space-sm) var(--space-lg);
  overflow: hidden;
}

.hero__bg {
  position: absolute;
  inset: 0;
  z-index: -2;
}

.hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero__overlay {
  position: absolute;
  inset: 0;
  background: var(--hero-overlay);
  z-index: -1;
}

.hero__content {
  text-align: center;
  max-width: 800px;
}

.hero__title {
  font-size: clamp(2rem, 6vw, 3.75rem);
  color: var(--hero-text);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: var(--space-md);
}

.hero__subtitle {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--hero-text-sub);
  margin-bottom: var(--space-lg);
  max-width: 600px;
  margin-left: auto;
  margin-right: auto;
}

.hero__cta {
  font-size: clamp(0.95rem, 1.5vw, 1.1rem);
}

/* --- Process --- */
.process {
  padding: var(--space-xl) 0;
  background: var(--bg-secondary);
  transition: background-color var(--transition-normal);
}

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

.process__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.process__step {
  position: relative;
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  padding: var(--space-md);
  text-align: center;
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), background-color var(--transition-normal);
  box-shadow: var(--card-shadow);
}

.process__step:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-shadow-hover);
}

.process__number {
  font-family: var(--font-heading);
  font-size: 2.5rem;
  font-weight: 700;
  color: var(--process-number);
  opacity: 0.2;
  line-height: 1;
  margin-bottom: var(--space-xs);
}

.process__icon {
  color: var(--color-primary);
  margin-bottom: var(--space-sm);
}

.process__icon svg {
  margin: 0 auto;
}

.process__title {
  font-size: 1.1rem;
  margin-bottom: var(--space-xs);
  color: var(--text-primary);
}

.process__desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* --- About --- */
.about {
  padding: var(--space-xl) 0;
  background: var(--bg-primary);
  transition: background-color var(--transition-normal);
}

.about__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-lg);
  align-items: center;
}

.about__image picture {
  border-radius: var(--radius);
  overflow: hidden;
}

.about__image img {
  width: 100%;
  height: auto;
  border-radius: var(--radius);
}

.about__text {
  font-size: clamp(1rem, 1.5vw, 1.15rem);
  color: var(--text-secondary);
  line-height: 1.7;
}

/* --- Technologies --- */
.technologies {
  padding: var(--space-xl) 0;
  background: var(--bg-secondary);
  transition: background-color var(--transition-normal);
}

.technologies .section-title {
  text-align: center;
}

.technologies__intro {
  text-align: center;
  color: var(--text-secondary);
  max-width: 700px;
  margin: 0 auto var(--space-lg);
  font-size: clamp(0.95rem, 1.3vw, 1.1rem);
  line-height: 1.6;
}

.technologies__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--space-md);
}

.tech-card {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--card-shadow);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal), background-color var(--transition-normal);
}

.tech-card:hover {
  transform: translateY(-6px);
  box-shadow: var(--card-shadow-hover);
}

.tech-card__image {
  overflow: hidden;
  aspect-ratio: 16 / 10;
}

.tech-card__image img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform var(--transition-normal);
}

.tech-card:hover .tech-card__image img {
  transform: scale(1.05);
}

.tech-card__body {
  padding: var(--space-md);
}

.tech-card__title {
  font-size: 1.15rem;
  margin-bottom: var(--space-xs);
  color: var(--text-primary);
}

.tech-card__desc {
  font-size: 0.95rem;
  color: var(--text-secondary);
  line-height: 1.5;
}

/* --- Contact --- */
.contact {
  position: relative;
  padding: var(--space-2xl) 0;
  overflow: hidden;
}

.contact__bg {
  position: absolute;
  inset: 0;
  z-index: -2;
}

.contact__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.contact__overlay {
  position: absolute;
  inset: 0;
  background: var(--contact-overlay);
  z-index: -1;
}

.contact__inner {
  text-align: center;
}

.contact__subtitle {
  font-size: clamp(1rem, 1.8vw, 1.2rem);
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: var(--space-lg);
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

.contact__items {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-sm);
}

.contact__item {
  display: inline-flex;
  align-items: center;
  gap: 0.75em;
  color: #FFFFFF;
  font-size: 1rem;
  padding: 0.6em 1.2em;
  border-radius: var(--radius-sm);
  background: rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  transition: background var(--transition-fast), transform var(--transition-fast);
}

a.contact__item:hover,
a.contact__item:focus-visible {
  background: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
}

.contact__icon {
  flex-shrink: 0;
  width: 20px;
  height: 20px;
}

.contact__noscript {
  color: rgba(255, 255, 255, 0.8);
  font-style: italic;
}

/* --- Footer --- */
.footer {
  background: var(--footer-bg);
  padding: var(--space-md) 0;
  transition: background-color var(--transition-normal);
}

.footer__inner {
  text-align: center;
}

.footer__copy {
  font-size: 0.85rem;
  color: var(--footer-text);
}

/* ==========================================================================
   Responsive — Mobile First
   ========================================================================== */

/* Tablet (768px+) */
@media (min-width: 768px) {
  .container {
    padding: 0 var(--space-md);
  }

  .process__grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-md);
  }

  .about__inner {
    grid-template-columns: 1fr 1fr;
  }

  .technologies__grid {
    grid-template-columns: repeat(3, 1fr);
  }

  .contact__items {
    flex-direction: row;
    flex-wrap: wrap;
    justify-content: center;
  }
}

/* Desktop (1024px+) */
@media (min-width: 1024px) {
  .container {
    padding: 0 var(--space-lg);
  }

  .process__grid {
    grid-template-columns: repeat(4, 1fr);
    gap: var(--space-md);
  }

  .about__inner {
    grid-template-columns: 2fr 3fr;
    gap: var(--space-xl);
  }

  .technologies__grid {
    gap: var(--space-md);
  }
}

/* Mobile (< 768px) */
@media (max-width: 767px) {
  .header__nav {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--header-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: var(--space-md);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition-normal), opacity var(--transition-normal);
    box-shadow: var(--header-shadow);
  }

  .header__nav.open {
    transform: translateY(0);
    opacity: 1;
    pointer-events: all;
  }

  .header__nav-list {
    flex-direction: column;
    gap: var(--space-sm);
    text-align: center;
  }

  .header__nav-link {
    font-size: 1.1rem;
    display: block;
    padding: var(--space-xs) 0;
  }

  .header__burger {
    display: flex;
  }
}

/* Large desktop (1280px+) */
@media (min-width: 1280px) {
  .hero__title {
    font-size: 4rem;
  }

  .process__step {
    padding: var(--space-lg) var(--space-md);
  }
}

/* Focus visible for keyboard navigation */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
}

/* Reduce motion for accessibility */
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }

  .fade-in {
    opacity: 1;
    transform: none;
  }
}