/* ========================================
   Custom Properties
   ======================================== */
:root {
  --color-bg: #fafafa;
  --color-text: #1a1a1a;
  --color-text-muted: #6b7280;
  --color-accent: #2563eb;
  --color-accent-hover: #1d4ed8;
  --color-border: #e5e7eb;
  --color-card-bg: #ffffff;
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --section-padding: clamp(60px, 10vw, 120px);
  --container-width: 1120px;
  --radius: 8px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.1);
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  color: var(--color-text);
  background-color: var(--color-bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

ul {
  list-style: none;
}

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

/* ========================================
   Layout
   ======================================== */
.container {
  width: 100%;
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 24px;
}

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

.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  margin-bottom: 48px;
  letter-spacing: -0.02em;
}

/* ========================================
   Navigation
   ======================================== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: rgba(250, 250, 250, 0.9);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--color-border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.nav__logo {
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.nav__menu {
  display: flex;
  gap: 32px;
}

.nav__link {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-muted);
  transition: color var(--transition);
}

.nav__link:hover {
  color: var(--color-text);
}

.nav__toggle {
  display: none;
  width: 40px;
  height: 40px;
  align-items: center;
  justify-content: center;
}

.nav__hamburger {
  display: block;
  width: 20px;
  height: 2px;
  background-color: var(--color-text);
  position: relative;
  transition: background-color var(--transition);
}

.nav__hamburger::before,
.nav__hamburger::after {
  content: '';
  position: absolute;
  left: 0;
  width: 100%;
  height: 2px;
  background-color: var(--color-text);
  transition: transform var(--transition);
}

.nav__hamburger::before {
  top: -6px;
}

.nav__hamburger::after {
  top: 6px;
}

/* Hamburger active state */
.nav__toggle[aria-expanded="true"] .nav__hamburger {
  background-color: transparent;
}

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

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

/* ========================================
   Hero
   ======================================== */
.hero {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: 100vh;
  text-align: center;
  padding: 64px 24px 0;
  position: relative;
}

.hero__greeting {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  margin-bottom: 8px;
  font-weight: 500;
}

.hero__name {
  font-size: clamp(2.5rem, 8vw, 5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 12px;
}

.hero__title {
  font-size: clamp(1.25rem, 3vw, 1.75rem);
  color: var(--color-accent);
  font-weight: 600;
  margin-bottom: 24px;
}

.hero__tagline {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  max-width: 480px;
  margin: 0 auto;
  line-height: 1.6;
}

.hero__scroll-indicator {
  position: absolute;
  bottom: 40px;
  color: var(--color-text-muted);
  animation: bounce 2s ease infinite;
}

@keyframes bounce {
  0%, 20%, 50%, 80%, 100% {
    transform: translateY(0);
  }
  40% {
    transform: translateY(8px);
  }
  60% {
    transform: translateY(4px);
  }
}

/* ========================================
   Projects
   ======================================== */
.projects {
  background-color: var(--color-bg);
}

.projects__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.project-card {
  display: block;
  background: var(--color-card-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition), box-shadow var(--transition);
}

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

.project-card__image {
  width: 100%;
  aspect-ratio: 16 / 10;
}

.project-card__body {
  padding: 24px;
}

.project-card__title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.project-card__desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  margin-bottom: 16px;
  line-height: 1.6;
}

.project-card__link {
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-accent);
  transition: color var(--transition);
}

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

/* ========================================
   Services
   ======================================== */
.services {
  background-color: var(--color-card-bg);
}

.services__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
}

.service-card {
  padding: 32px;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.service-card:hover {
  border-color: var(--color-accent);
  box-shadow: var(--shadow-sm);
}

.service-card__title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.service-card__desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ========================================
   AI Consulting & Workshops
   ======================================== */
.ai__intro {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  max-width: 640px;
  margin-top: -32px;
  margin-bottom: 48px;
  line-height: 1.7;
}

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

.ai__column {
  padding: 32px;
  background-color: var(--color-card-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
}

.ai__heading {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.01em;
}

.ai__desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.7;
  margin-bottom: 20px;
}

.ai__list {
  list-style: none;
  padding: 0;
}

.ai__list li {
  font-size: 0.9375rem;
  color: var(--color-text);
  padding: 8px 0;
  padding-left: 20px;
  position: relative;
  border-bottom: 1px solid var(--color-border);
}

.ai__list li:last-child {
  border-bottom: none;
}

.ai__list li::before {
  content: '';
  position: absolute;
  left: 0;
  top: 50%;
  transform: translateY(-50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background-color: var(--color-accent);
}

.ai__cta {
  margin-top: 40px;
}

.ai__button {
  display: inline-block;
  padding: 14px 36px;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 1rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: background-color var(--transition);
}

.ai__button:hover {
  background-color: var(--color-accent-hover);
}

/* ========================================
   Experience / Timeline
   ======================================== */
.timeline {
  position: relative;
  padding-left: 32px;
}

.timeline::before {
  content: '';
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background-color: var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: 40px;
}

.timeline__item:last-child {
  padding-bottom: 0;
}

.timeline__marker {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--color-bg);
  border: 2px solid var(--color-accent);
  z-index: 1;
}

.timeline__date {
  display: inline-block;
  font-size: 0.8125rem;
  font-weight: 600;
  color: var(--color-accent);
  margin-bottom: 4px;
  letter-spacing: 0.02em;
}

.timeline__title {
  font-size: 1.125rem;
  font-weight: 600;
  margin-bottom: 2px;
  letter-spacing: -0.01em;
}

.timeline__company {
  font-size: 0.9375rem;
  font-weight: 500;
  color: var(--color-text-muted);
  margin-bottom: 8px;
}

.timeline__desc {
  font-size: 0.9375rem;
  color: var(--color-text-muted);
  line-height: 1.7;
}

/* ========================================
   About
   ======================================== */
.about__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
  align-items: center;
}

.about__image-placeholder {
  width: 100%;
  aspect-ratio: 4 / 5;
  background-color: var(--color-border);
  border-radius: var(--radius);
}

.about__content p {
  font-size: clamp(0.9375rem, 2vw, 1.0625rem);
  color: var(--color-text-muted);
  margin-bottom: 20px;
  line-height: 1.8;
}

.about__content p:last-child {
  margin-bottom: 0;
}

/* ========================================
   Contact
   ======================================== */
.contact {
  background-color: var(--color-card-bg);
}

.contact__intro {
  font-size: clamp(1rem, 2vw, 1.25rem);
  color: var(--color-text-muted);
  margin-top: -32px;
  margin-bottom: 48px;
}

.contact__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 48px;
}

/* Form */
.form__group {
  margin-bottom: 20px;
}

.form__label {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  margin-bottom: 6px;
}

.form__input {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font-family);
  font-size: 0.9375rem;
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  background: var(--color-bg);
  color: var(--color-text);
  transition: border-color var(--transition);
}

.form__input:focus {
  outline: none;
  border-color: var(--color-accent);
}

.form__textarea {
  resize: vertical;
  min-height: 120px;
}

.form__button {
  display: inline-block;
  padding: 12px 32px;
  background-color: var(--color-accent);
  color: #ffffff;
  font-size: 0.9375rem;
  font-weight: 600;
  border-radius: var(--radius);
  transition: background-color var(--transition);
}

.form__button:hover {
  background-color: var(--color-accent-hover);
}

/* Contact Info */
.contact__info {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.contact__email a {
  font-size: 1.125rem;
  font-weight: 500;
  color: var(--color-accent);
  transition: color var(--transition);
}

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

.contact__socials {
  display: flex;
  gap: 16px;
}

.contact__social-link {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background-color: var(--color-bg);
  color: var(--color-text-muted);
  transition: color var(--transition), background-color var(--transition);
}

.contact__social-link:hover {
  color: var(--color-accent);
  background-color: var(--color-border);
}

/* ========================================
   Footer
   ======================================== */
.footer {
  padding: 32px 0;
  text-align: center;
  font-size: 0.875rem;
  color: var(--color-text-muted);
  border-top: 1px solid var(--color-border);
}

/* ========================================
   Fade-in Animation
   ======================================== */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

/* ========================================
   Responsive — Tablet (768px+)
   ======================================== */
@media (min-width: 768px) {
  .projects__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .services__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .ai__grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .about__grid {
    grid-template-columns: 1fr 1.5fr;
  }

  .contact__grid {
    grid-template-columns: 1.5fr 1fr;
    align-items: start;
  }
}

/* ========================================
   Responsive — Desktop (1024px+)
   ======================================== */
@media (min-width: 1024px) {
  .projects__grid {
    grid-template-columns: repeat(3, 1fr);
  }

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

/* ========================================
   Responsive — Mobile (< 768px)
   ======================================== */
@media (max-width: 767px) {
  .nav__toggle {
    display: flex;
  }

  .nav__menu {
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    background-color: rgba(250, 250, 250, 0.98);
    backdrop-filter: blur(12px);
    flex-direction: column;
    align-items: center;
    gap: 0;
    padding: 16px 0;
    border-bottom: 1px solid var(--color-border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: transform var(--transition), opacity var(--transition);
  }

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

  .nav__menu li {
    width: 100%;
    text-align: center;
  }

  .nav__link {
    display: block;
    padding: 12px 24px;
    font-size: 1rem;
  }
}