/* ========================
   Reset & Custom Properties
   ======================== */

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

:root {
  /* Colors */
  --color-bg: #0a0a0a;
  --color-text-primary: #ffffff;
  --color-text-secondary: #a0a0a0;
  --color-text-tertiary: #777777;
  --color-accent: #e84393;
  --color-border-section: #1a1a1a;
  --color-border-card: #222222;
  --color-border-hover: #333333;

  /* Typography */
  --font-family: -apple-system, 'Helvetica Neue', Helvetica, Arial, sans-serif;

  /* Spacing */
  --section-padding: 6rem 1.5rem;
  --container-max: 1120px;

  /* Transitions */
  --transition-fast: 300ms ease;
  --transition-normal: 600ms ease;
}

html {
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }
}

body {
  background-color: var(--color-bg);
  color: var(--color-text-primary);
  font-family: var(--font-family);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

a:hover {
  color: var(--color-text-primary);
}

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

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ========================
   Navigation
   ======================== */

#site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background-color: var(--color-bg);
  transition: background-color var(--transition-fast);
}

#site-header.scrolled {
  background-color: var(--color-bg);
}

.nav-container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 1.25rem 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--color-text-primary);
  letter-spacing: 0.05em;
}

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

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--color-text-secondary);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  transition: color var(--transition-fast);
}

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

.nav-links a.active {
  border-bottom: 2px solid var(--color-accent);
  padding-bottom: 2px;
}

.nav-lang {
  font-weight: 700;
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  border: 1px solid var(--color-text-tertiary);
  border-radius: 4px;
  padding: 0.2rem 0.5rem;
  color: var(--color-text-secondary);
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.nav-lang:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* Hamburger button — hidden on desktop */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  flex-direction: column;
  gap: 5px;
}

.nav-toggle-bar {
  display: block;
  width: 24px;
  height: 2px;
  background-color: var(--color-text-primary);
  transition: transform var(--transition-fast), opacity var(--transition-fast);
}

/* Mobile nav */
@media (max-width: 768px) {
  .nav-toggle {
    display: flex;
  }

  .nav-links {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 99;
    background-color: var(--color-bg);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2.5rem;
  }

  .nav-links.open {
    display: flex;
  }

  .nav-links a {
    font-size: 1.5rem;
  }

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

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

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

/* ========================
   Hero
   ======================== */

#hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 0 1.5rem;
}

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

.hero-label {
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  color: var(--color-text-secondary);
  margin-bottom: 1.5rem;
  text-transform: uppercase;
}

.hero-statement {
  font-size: clamp(1.75rem, 5vw, 3.25rem);
  font-weight: 700;
  line-height: 1.15;
  margin-bottom: 1.5rem;
}

.hero-subtitle {
  font-size: 1.125rem;
  color: var(--color-text-secondary);
  margin-bottom: 2.5rem;
  line-height: 1.5;
}

.hero-cta {
  display: inline-block;
  padding: 0.75rem 2rem;
  border: 1.5px solid var(--color-text-secondary);
  border-radius: 999px;
  color: var(--color-text-primary);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  transition: border-color var(--transition-fast), color var(--transition-fast);
}

.arrow-down,
.arrow-right,
.arrow-left,
.arrow-up-right {
  display: inline-block;
  width: 0.45em;
  height: 0.45em;
  border-right: 1.5px solid currentColor;
  border-bottom: 1.5px solid currentColor;
  margin-left: 0.3em;
  vertical-align: middle;
  position: relative;
}

.arrow-down {
  transform: rotate(45deg);
  top: -0.15em;
}

.arrow-right {
  transform: rotate(-45deg);
  top: -0.05em;
}

.arrow-left {
  transform: rotate(135deg);
  top: -0.05em;
  margin-left: 0;
  margin-right: 0.3em;
}

.arrow-up-right {
  transform: rotate(-90deg);
  top: 0.05em;
}

.hero-cta:hover {
  border-color: var(--color-accent);
  background-color: var(--color-accent);
  color: var(--color-text-primary);
}

@media (max-width: 768px) {
  .hero-subtitle {
    font-size: 1rem;
  }
}

/* ========================
   Shared Section Styles
   ======================== */

.section-title {
  font-size: 0.75rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--color-text-secondary);
  margin-bottom: 2rem;
}

section {
  padding: var(--section-padding);
  scroll-margin-top: 4rem;
  border-top: 1px solid var(--color-border-section);
}

#hero {
  border-top: none;
}

/* ========================
   About
   ======================== */

.about-content {
  max-width: 900px;
  margin: 0 auto;
  text-align: left;
}

.about-layout {
  display: flex;
  gap: 2.5rem;
  align-items: center;
}

.about-photo {
  width: 260px;
  height: 260px;
  object-fit: cover;
  border-radius: 4px;
  flex-shrink: 0;
}

.about-text {
  font-size: 1.125rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

@media (max-width: 768px) {
  .about-layout {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }

  .about-photo {
    width: 200px;
    height: 200px;
  }
}

/* ========================
   Case Studies
   ======================== */

.case {
  margin-bottom: 6rem;
}

.case:last-child {
  margin-bottom: 0;
}

.case-header {
  margin-bottom: 3rem;
}

.case-number {
  display: block;
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 700;
  color: #1a1a1a;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.case-title {
  font-size: 1.375rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.case-tags {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.02em;
}

.case-section {
  margin-bottom: 3rem;
}

.zigzag {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
}

.zigzag.reverse .case-text {
  order: 2;
}

.zigzag.reverse .case-image {
  order: 1;
}

.stacked {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

.stacked .case-image {
  width: 100%;
}

.case-text h4 {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
  margin-bottom: 0.75rem;
}

.case-text p {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.case-image img {
  width: 100%;
  border-radius: 4px;
  border: 1px solid var(--color-border-card);
}

.case-impact {
  padding: 2rem 0;
  border-top: 1px solid var(--color-border-section);
}

.case-impact h4 {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
  margin-bottom: 0.75rem;
}

.case-impact p {
  font-size: 1rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
}

/* Mobile: stack vertically */
@media (max-width: 768px) {
  .zigzag {
    grid-template-columns: 1fr;
    gap: 1.5rem;
  }

  .zigzag.reverse .case-text {
    order: 1;
  }

  .zigzag.reverse .case-image {
    order: 2;
  }

  .case-number {
    font-size: 3rem;
  }
}

/* ========================
   AI Cards
   ======================== */

.ai-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.5rem;
}

.ai-card {
  border: 1px solid var(--color-border-card);
  border-radius: 8px;
  padding: 2rem;
  transition: border-color var(--transition-fast);
}

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

.ai-card-title {
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 0.75rem;
}

.ai-card-desc {
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  margin-bottom: 1rem;
}

.ai-card-tool {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.02em;
}

@media (max-width: 768px) {
  .ai-cards {
    grid-template-columns: 1fr;
  }
}

/* ========================
   CV
   ======================== */

.cv-grid {
  display: grid;
  grid-template-columns: 160px 1fr;
  gap: 2rem 3rem;
}

.cv-label {
  font-size: 0.75rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
  padding-top: 0.25rem;
}

.cv-content {
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--color-border-section);
}

.cv-entry {
  margin-bottom: 1.5rem;
}

.cv-entry:last-child {
  margin-bottom: 0;
}

.cv-entry-header {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1rem;
}

.cv-entry-header h3 {
  font-size: 1rem;
  font-weight: 600;
}

.cv-date {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  white-space: nowrap;
}

.cv-company {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
  margin-top: 0.25rem;
}

.cv-desc {
  font-size: 0.875rem;
  color: var(--color-text-tertiary);
  margin-top: 0.25rem;
  line-height: 1.5;
}

.cv-skills {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.25rem;
}

.cv-skill-group h3 {
  font-size: 0.8125rem;
  font-weight: 600;
  margin-bottom: 0.25rem;
}

.cv-skill-group p {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.cv-download {
  margin-top: 3rem;
  text-align: center;
}

.btn-download {
  display: inline-block;
  padding: 0.75rem 2rem;
  border: 1.5px solid var(--color-accent);
  border-radius: 999px;
  color: var(--color-accent);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.btn-download:hover {
  background-color: var(--color-accent);
  color: var(--color-text-primary);
}

@media (max-width: 768px) {
  .cv-grid {
    grid-template-columns: 1fr;
    gap: 1rem;
  }

  .cv-label {
    margin-top: 1.5rem;
  }

  .cv-skills {
    grid-template-columns: 1fr;
  }

  .cv-entry-header {
    flex-direction: column;
    gap: 0.25rem;
  }
}

/* ========================
   Contact
   ======================== */

.contact-content {
  max-width: 640px;
  margin: 0 auto;
  text-align: center;
}

.contact-intent {
  font-size: 1.25rem;
  line-height: 1.6;
  margin-bottom: 2rem;
  color: var(--color-text-secondary);
}

.contact-links {
  display: flex;
  gap: 1.5rem;
  justify-content: center;
  align-items: center;
}

.contact-cta {
  display: inline-block;
  padding: 0.75rem 2rem;
  border: 1.5px solid var(--color-accent);
  border-radius: 999px;
  color: var(--color-accent);
  font-size: 0.875rem;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.contact-cta:hover {
  background-color: var(--color-accent);
  color: var(--color-text-primary);
}

.contact-link {
  font-size: 0.875rem;
  color: var(--color-text-secondary);
}

/* ========================
   Footer
   ======================== */

footer {
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--color-border-section);
  text-align: center;
}

footer p {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

/* ========================
   Scroll Animations
   ======================== */

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity var(--transition-normal), transform var(--transition-normal);
}

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

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

/* ========================
   Case Cards (Home)
   ======================== */

.case-card {
  display: block;
  margin-bottom: 4rem;
  text-decoration: none;
  color: inherit;
  border: 1px solid var(--color-border-card);
  border-radius: 8px;
  padding: 2.5rem;
  transition: border-color var(--transition-fast);
}

.case-card:last-child {
  margin-bottom: 0;
}

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

.case-card .case-number {
  margin-bottom: 0.5rem;
}

.case-card .case-title {
  margin-bottom: 0.5rem;
}

.case-card .case-tags {
  margin-bottom: 1rem;
}

.case-card-summary {
  font-size: 1rem;
  line-height: 1.7;
  color: var(--color-text-secondary);
  margin-bottom: 1.5rem;
}

.case-card-cta {
  display: inline-block;
  font-size: 0.875rem;
  color: var(--color-accent);
  letter-spacing: 0.02em;
}

.case-card:hover .case-card-cta {
  color: var(--color-text-primary);
}

@media (max-width: 768px) {
  .case-card {
    padding: 1.5rem;
    margin-bottom: 2rem;
  }
}

/* ========================
   Case Detail Page
   ======================== */

.case-detail-header {
  padding: 8rem 1.5rem 3rem;
  max-width: var(--container-max);
  margin: 0 auto;
}

.case-detail-header .case-number {
  display: block;
  font-size: clamp(3rem, 8vw, 6rem);
  font-weight: 700;
  color: #1a1a1a;
  line-height: 1;
  margin-bottom: 0.5rem;
}

.case-detail-header .case-title {
  font-size: 1.375rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
}

.case-detail-header .case-tags {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
  letter-spacing: 0.02em;
}

.case-meta {
  display: flex;
  gap: 2.5rem;
  padding: 1.5rem 0;
  margin: 2rem 0 0;
  border-top: 1px solid var(--color-border-section);
  border-bottom: 1px solid var(--color-border-section);
}

.case-meta-item {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.case-meta-label {
  font-size: 0.625rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--color-text-tertiary);
}

.case-meta-value {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
}

@media (max-width: 768px) {
  .case-meta {
    flex-wrap: wrap;
    gap: 1.5rem;
  }
}

.case-highlight {
  padding: 2rem 0;
  margin: 2rem 0;
  border-left: 2px solid var(--color-accent);
  padding-left: 1.5rem;
}

.case-highlight p {
  font-size: 1.125rem;
  line-height: 1.6;
  color: var(--color-text-secondary);
  font-style: italic;
}

.case-detail-body {
  padding: var(--section-padding);
  max-width: var(--container-max);
  margin: 0 auto;
  padding-left: 1.5rem;
  padding-right: 1.5rem;
}

.case-nav {
  padding: 3rem 1.5rem 6rem;
  text-align: center;
}

.case-nav-link {
  display: inline-block;
  padding: 0.75rem 2rem;
  border: 1.5px solid var(--color-text-secondary);
  border-radius: 999px;
  color: var(--color-text-primary);
  font-size: 0.875rem;
  letter-spacing: 0.02em;
  transition: border-color var(--transition-fast), background-color var(--transition-fast), color var(--transition-fast);
}

.case-nav-link:hover {
  border-color: var(--color-accent);
  background-color: var(--color-accent);
  color: var(--color-text-primary);
}