/* ───────────────────────────────
   Reset & Base
   ─────────────────────────────── */

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

:root {
  --color-bg: #fbfbfd;
  --color-bg-alt: #f5f5f7;
  --color-text: #1d1d1f;
  --color-text-secondary: #6e6e73;
  --color-accent: #0071e3;
  --color-accent-hover: #0077ed;
  --color-border: #d2d2d7;
  --color-card-bg: #ffffff;
  --color-dark-bg: #1d1d1f;
  --color-dark-text: #f5f5f7;
  --header-height: 52px;
  --container-max: 980px;
  --container-wide: 1120px;
  --font-sans: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display",
    "Helvetica Neue", Helvetica, Arial, sans-serif;
  --transition-base: 0.3s cubic-bezier(0.25, 0.1, 0.25, 1);
}

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

body {
  font-family: var(--font-sans);
  color: var(--color-text);
  background: var(--color-bg);
  line-height: 1.5;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

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

.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}


/* ───────────────────────────────
   Header / Navigation
   ─────────────────────────────── */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  height: var(--header-height);
  background: rgba(251, 251, 253, 0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.06);
  transition: background var(--transition-base);
}

.nav-container {
  max-width: var(--container-wide);
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
  transition: opacity var(--transition-base);
}

.nav-logo:hover {
  opacity: 0.7;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 32px;
}

.nav-links a {
  font-size: 13px;
  font-weight: 400;
  color: var(--color-text-secondary);
  transition: color var(--transition-base);
  white-space: nowrap;
}

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

.nav-links .nav-contact {
  color: var(--color-accent);
  font-weight: 500;
}

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

.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  gap: 6px;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 18px;
  height: 1.5px;
  background: var(--color-text);
  border-radius: 2px;
  transition: all 0.25s ease;
}

.nav-toggle.active span:first-child {
  transform: translateY(3.75px) rotate(45deg);
}

.nav-toggle.active span:last-child {
  transform: translateY(-3.75px) rotate(-45deg);
}


/* ───────────────────────────────
   Hero
   ─────────────────────────────── */

.hero {
  padding: 160px 0 120px;
  text-align: center;
  min-height: 85vh;
  display: flex;
  align-items: center;
}

.hero-greeting {
  font-size: 21px;
  font-weight: 400;
  color: var(--color-text-secondary);
  margin-bottom: 12px;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s ease forwards 0.2s;
}

.hero-name {
  font-size: clamp(44px, 8vw, 80px);
  font-weight: 700;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 20px;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s ease forwards 0.4s;
}

.hero-tagline {
  font-size: clamp(18px, 2.5vw, 24px);
  font-weight: 400;
  color: var(--color-text-secondary);
  line-height: 1.5;
  margin-bottom: 40px;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s ease forwards 0.6s;
}

.hero-cta {
  display: flex;
  gap: 16px;
  justify-content: center;
  flex-wrap: wrap;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.8s ease forwards 0.8s;
}


/* ───────────────────────────────
   Buttons
   ─────────────────────────────── */

.btn {
  display: inline-block;
  font-size: 15px;
  font-weight: 500;
  padding: 12px 28px;
  border-radius: 980px;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
}

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

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

.btn-secondary {
  background: transparent;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
}

.btn-secondary:hover {
  background: var(--color-accent);
  color: #fff;
}


/* ───────────────────────────────
   Section Shared
   ─────────────────────────────── */

.section-label {
  font-size: 13px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-text-secondary);
  margin-bottom: 48px;
}


/* ───────────────────────────────
   About
   ─────────────────────────────── */

.about {
  padding: 100px 0;
  background: var(--color-bg-alt);
}

.about-content {
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 64px;
  align-items: start;
}

.about-lead {
  font-size: 24px;
  font-weight: 600;
  line-height: 1.4;
  letter-spacing: -0.01em;
  margin-bottom: 24px;
  color: var(--color-text);
}

.about-text p {
  font-size: 17px;
  color: var(--color-text-secondary);
  line-height: 1.65;
  margin-bottom: 16px;
}

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

.about-details {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.detail-card {
  background: var(--color-card-bg);
  border-radius: 16px;
  padding: 28px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
}

.detail-number {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--color-text);
}

.detail-label {
  font-size: 13px;
  color: var(--color-text-secondary);
  font-weight: 500;
}


/* ───────────────────────────────
   Work / Projects
   ─────────────────────────────── */

.work {
  padding: 100px 0;
}

.work-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.work-card {
  display: block;
  background: var(--color-bg-alt);
  border-radius: 20px;
  overflow: hidden;
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.work-card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.08);
}

.work-card-inner {
  padding: 40px 36px;
  min-height: 260px;
  display: flex;
  flex-direction: column;
}

.work-tag {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-accent);
  margin-bottom: 16px;
}

.work-card h3 {
  font-size: 24px;
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
  line-height: 1.2;
}

.work-card p {
  font-size: 15px;
  color: var(--color-text-secondary);
  line-height: 1.6;
  flex-grow: 1;
}

.work-link {
  font-size: 15px;
  font-weight: 500;
  color: var(--color-accent);
  margin-top: 20px;
  transition: opacity var(--transition-base);
}

.work-card:hover .work-link {
  opacity: 0.8;
}


/* ───────────────────────────────
   Experience / Timeline
   ─────────────────────────────── */

.experience {
  padding: 100px 0;
  background: var(--color-dark-bg);
  color: var(--color-dark-text);
}

.experience .section-label {
  color: rgba(245, 245, 247, 0.5);
}

.timeline {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.timeline-item {
  display: grid;
  grid-template-columns: 200px 1fr;
  gap: 40px;
  padding: 32px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  align-items: baseline;
}

.timeline-item:first-child {
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

.timeline-date {
  font-size: 14px;
  font-weight: 500;
  color: rgba(245, 245, 247, 0.5);
  white-space: nowrap;
}

.timeline-content h3 {
  font-size: 19px;
  font-weight: 600;
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}

.timeline-company {
  font-size: 15px;
  color: rgba(245, 245, 247, 0.5);
}


/* ───────────────────────────────
   Education
   ─────────────────────────────── */

.education {
  padding: 100px 0;
}

.edu-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}

.edu-card {
  background: var(--color-bg-alt);
  border-radius: 20px;
  padding: 40px 36px;
}

.edu-card h3 {
  font-size: 21px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 6px;
}

.edu-card > p {
  font-size: 15px;
  color: var(--color-text-secondary);
  margin-bottom: 20px;
}

.edu-highlights {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.edu-highlights li {
  font-size: 14px;
  color: var(--color-text-secondary);
  padding-left: 16px;
  position: relative;
  line-height: 1.5;
}

.edu-highlights li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--color-accent);
}


/* ───────────────────────────────
   Contact
   ─────────────────────────────── */

.contact {
  padding: 100px 0;
  background: var(--color-bg-alt);
  text-align: center;
}

.contact-lead {
  font-size: clamp(20px, 3vw, 28px);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: 40px;
  line-height: 1.4;
}

.contact-links {
  display: flex;
  gap: 20px;
  justify-content: center;
  flex-wrap: wrap;
}

.contact-link {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-size: 17px;
  font-weight: 500;
  color: var(--color-accent);
  padding: 14px 32px;
  border-radius: 980px;
  border: 1px solid var(--color-accent);
  transition: all var(--transition-base);
}

.contact-link:hover {
  background: var(--color-accent);
  color: #fff;
}

.contact-icon {
  display: flex;
  align-items: center;
}

.contact-icon svg {
  width: 20px;
  height: 20px;
}


/* ───────────────────────────────
   Footer
   ─────────────────────────────── */

.site-footer {
  padding: 20px 0;
  text-align: center;
  background: var(--color-bg);
  border-top: 1px solid rgba(0, 0, 0, 0.06);
}

.site-footer p {
  font-size: 12px;
  color: var(--color-text-secondary);
}


/* ───────────────────────────────
   Scroll Animations
   ─────────────────────────────── */

.fade-in {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

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

@keyframes fadeUp {
  to {
    opacity: 1;
    transform: translateY(0);
  }
}


/* ───────────────────────────────
   Responsive — Tablet
   ─────────────────────────────── */

@media (max-width: 768px) {
  :root {
    --header-height: 48px;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(251, 251, 253, 0.97);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 28px;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.3s ease, visibility 0.3s ease;
  }

  .nav-links.open {
    opacity: 1;
    visibility: visible;
  }

  .nav-links a {
    font-size: 22px;
    font-weight: 500;
    color: var(--color-text);
  }

  .nav-links .nav-contact {
    font-size: 22px;
  }

  .hero {
    padding: 130px 0 80px;
    min-height: 75vh;
  }

  .about-content {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .about-details {
    flex-direction: row;
    flex-wrap: wrap;
  }

  .detail-card {
    flex: 1;
    min-width: 120px;
  }

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

  .work-card-inner {
    min-height: auto;
    padding: 32px 28px;
  }

  .timeline-item {
    grid-template-columns: 1fr;
    gap: 4px;
    padding: 24px 0;
  }

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


/* ───────────────────────────────
   Responsive — Small mobile
   ─────────────────────────────── */

@media (max-width: 440px) {
  .container {
    padding: 0 18px;
  }

  .hero {
    padding: 110px 0 60px;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .btn {
    width: 100%;
    max-width: 280px;
    text-align: center;
  }

  .about-details {
    flex-direction: column;
  }

  .detail-card {
    flex-direction: row;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
  }

  .detail-number {
    font-size: 24px;
  }

  .contact-links {
    flex-direction: column;
    align-items: center;
  }

  .contact-link {
    width: 100%;
    max-width: 280px;
    justify-content: center;
  }

  .section-label {
    margin-bottom: 32px;
  }

  .about,
  .work,
  .experience,
  .education,
  .contact {
    padding: 72px 0;
  }
}