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

:root {
  --color-bg: #faf6f1;
  --color-surface: #ffffff;
  --color-surface-alt: #f3ece4;
  --color-border: #e4dcd2;
  --color-text: #3d3229;
  --color-text-muted: #7a6e62;
  --color-accent: #c4654a;
  --color-accent-hover: #a8503a;
  --color-white: #2b2017;
  --font-sans: "Inter", system-ui, -apple-system, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, monospace;
  --radius: 12px;
  --radius-sm: 8px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

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

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

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

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

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* ===== Navigation ===== */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: rgba(250, 246, 241, 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-weight: 700;
  font-size: 1.25rem;
  color: var(--color-white);
  letter-spacing: -0.02em;
}

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

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

.nav__links a {
  color: var(--color-text-muted);
  font-size: 0.875rem;
  font-weight: 500;
  transition: color var(--transition);
}

.nav__links a:hover {
  color: var(--color-white);
}

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

.nav__toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--color-text);
  border-radius: 2px;
  transition: var(--transition);
}

.nav__toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav__toggle.open span:nth-child(2) { opacity: 0; }
.nav__toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ===== Sections ===== */
section {
  padding: 6rem 0;
}

.section-label {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--color-accent);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-bottom: 0.75rem;
}

.section-title {
  font-size: 2rem;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: -0.03em;
  margin-bottom: 2rem;
}

/* ===== Hero ===== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 64px;
}

.hero__inner {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: 4rem;
  align-items: center;
}

.hero__greeting {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--color-accent);
  margin-bottom: 1rem;
}

.hero__name {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: -0.04em;
  line-height: 1.1;
  margin-bottom: 1.25rem;
}

.hero__tagline {
  font-size: 1.15rem;
  color: var(--color-text-muted);
  max-width: 540px;
  margin-bottom: 2rem;
}

.hero__links {
  display: flex;
  gap: 1rem;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.75rem 1.5rem;
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  transition: all var(--transition);
}

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

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

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

.btn--outline:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

/* Photo placeholder */
.photo-placeholder {
  width: 280px;
  height: 340px;
  border-radius: var(--radius);
  background: var(--color-surface-alt);
  border: 2px dashed var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
  text-align: center;
  padding: 1rem;
}

/* ===== About ===== */
.about__content {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
}

.about__text {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  line-height: 1.8;
  max-width: 720px;
}

/* ===== Education ===== */
.edu-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.edu-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.75rem;
  box-shadow: 0 2px 8px rgba(60, 50, 40, 0.06);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.edu-card:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 16px rgba(60, 50, 40, 0.1);
}

.edu-card__school {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 0.25rem;
}

.edu-card__degree {
  color: var(--color-text-muted);
  font-size: 0.9rem;
  margin-bottom: 0.5rem;
}

.edu-card__detail {
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ===== Experience ===== */
.timeline {
  position: relative;
  padding-left: 2rem;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5rem;
  bottom: 0.5rem;
  width: 2px;
  background: var(--color-border);
}

.timeline__item {
  position: relative;
  padding-bottom: 3rem;
}

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

.timeline__item::before {
  content: "";
  position: absolute;
  left: -2rem;
  top: 0.5rem;
  width: 12px;
  height: 12px;
  background: var(--color-accent);
  border-radius: 50%;
  transform: translateX(-5px);
}

.timeline__header {
  margin-bottom: 0.75rem;
}

.timeline__company {
  font-size: 1.15rem;
  font-weight: 600;
  color: var(--color-white);
}

.timeline__role {
  font-size: 0.9rem;
  color: var(--color-accent);
}

.timeline__meta {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  color: var(--color-text-muted);
  margin-top: 0.15rem;
}

.timeline__body {
  color: var(--color-text-muted);
  font-size: 0.95rem;
  line-height: 1.75;
}

/* ===== Projects ===== */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 1.5rem;
}

.project-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: 0 2px 8px rgba(60, 50, 40, 0.06);
  transition: border-color var(--transition), transform var(--transition), box-shadow var(--transition);
}

.project-card:hover {
  border-color: var(--color-accent);
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(60, 50, 40, 0.1);
}

.project-card__img {
  width: 100%;
  height: 200px;
  background: var(--color-surface-alt);
  border-bottom: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-muted);
  font-size: 0.85rem;
}

.project-card__body {
  padding: 1.5rem;
}

.project-card__title {
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 0.5rem;
}

.project-card__desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.65;
  margin-bottom: 1rem;
}

.project-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.tag {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.25rem 0.6rem;
  background: var(--color-surface-alt);
  border: 1px solid var(--color-border);
  border-radius: 999px;
  color: var(--color-text-muted);
}

/* ===== Patents ===== */
.patents-list {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.patent-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
  box-shadow: 0 2px 8px rgba(60, 50, 40, 0.06);
  transition: border-color var(--transition), box-shadow var(--transition);
}

.patent-item:hover {
  border-color: var(--color-accent);
  box-shadow: 0 4px 16px rgba(60, 50, 40, 0.1);
}

.patent-item__title {
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 0.35rem;
}

.patent-item__desc {
  font-size: 0.9rem;
  color: var(--color-text-muted);
}

/* ===== Skills ===== */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1.5rem;
}

.skill-group {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.5rem;
}

.skill-group__title {
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--color-white);
  margin-bottom: 0.75rem;
}

.skill-group__items {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ===== Awards ===== */
.awards-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1rem;
}

.award-item {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  padding: 1.25rem;
}

.award-item__icon {
  flex-shrink: 0;
  width: 40px;
  height: 40px;
  background: var(--color-surface-alt);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.1rem;
}

.award-item__text {
  font-size: 0.9rem;
  color: var(--color-text-muted);
  line-height: 1.55;
}

.award-item__text strong {
  color: var(--color-white);
}

/* ===== Contact ===== */
.contact__inner {
  text-align: center;
  max-width: 560px;
  margin: 0 auto;
}

.contact__text {
  font-size: 1.05rem;
  color: var(--color-text-muted);
  margin-bottom: 2rem;
}

.contact__links {
  display: flex;
  justify-content: center;
  gap: 1rem;
  flex-wrap: wrap;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--color-border);
  padding: 2rem 0;
  text-align: center;
  font-size: 0.85rem;
  color: var(--color-text-muted);
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav__links {
    display: none;
    position: absolute;
    top: 64px;
    left: 0;
    right: 0;
    flex-direction: column;
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 1.5rem;
    gap: 1.25rem;
  }

  .nav__links.open {
    display: flex;
  }

  .nav__toggle {
    display: flex;
  }

  .hero__inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .photo-placeholder {
    margin: 0 auto;
    width: 200px;
    height: 240px;
    order: -1;
  }

  .hero__links {
    justify-content: center;
  }

  section {
    padding: 4rem 0;
  }

  .section-title {
    font-size: 1.6rem;
  }

  .edu-grid,
  .projects-grid,
  .skills-grid,
  .awards-grid {
    grid-template-columns: 1fr;
  }
}