/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
  --bg: #f8f8ff;
  --bg-secondary: #f0f0fa;
  --bg-card: #ffffff;
  --border: #e0e0ef;
  --text-primary: #1a1a2e;
  --text-secondary: #6b6b8a;
  --accent: #6c63ff;
  --accent-hover: #5a52e0;
  --accent-light: rgba(108, 99, 255, 0.10);
  --gradient: linear-gradient(135deg, #6c63ff 0%, #a855f7 100%);
  --font-main: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Courier New', monospace;
  --nav-height: 64px;
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --shadow: 0 4px 24px rgba(108, 99, 255, 0.10);
  --radius: 12px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--nav-height);
}

body {
  font-family: var(--font-main);
  background-color: var(--bg);
  color: var(--text-primary);
  line-height: 1.7;
  overflow-x: hidden;
}

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

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

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

ul { list-style: none; }

/* ===========================
   Utilities
   =========================== */
.container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
}

.section {
  padding: 100px 0;
}

.section__title {
  font-size: clamp(2rem, 4vw, 2.8rem);
  font-weight: 800;
  margin-bottom: 60px;
  letter-spacing: -0.03em;
}

.section__title span {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: 8px;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  border: 2px solid transparent;
  font-family: var(--font-main);
}

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

.btn--primary:hover {
  opacity: 0.88;
  transform: translateY(-2px);
  color: #fff;
  box-shadow: 0 8px 24px rgba(108, 99, 255, 0.35);
}

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

.btn--outline:hover {
  background: var(--accent-light);
  transform: translateY(-2px);
  color: var(--accent);
}

.btn--full { width: 100%; justify-content: center; }

.tag {
  display: inline-block;
  padding: 3px 10px;
  background: var(--accent-light);
  color: var(--accent);
  border-radius: 20px;
  font-size: 0.75rem;
  font-weight: 600;
  font-family: var(--font-mono);
}

/* ===========================
   Navigation
   =========================== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  z-index: 1000;
  transition: background var(--transition), backdrop-filter var(--transition);
}

.nav.scrolled {
  background: rgba(248, 248, 255, 0.88);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.nav__container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav__logo {
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-primary);
  letter-spacing: -0.04em;
}

.nav__logo-dot {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav__links {
  display: flex;
  gap: 36px;
  align-items: center;
}

.nav__link {
  color: var(--text-secondary);
  font-size: 0.9rem;
  font-weight: 500;
  transition: color var(--transition);
  position: relative;
}

.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient);
  transition: width var(--transition);
  border-radius: 2px;
}

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

.nav__link:hover::after,
.nav__link.active::after {
  width: 100%;
}

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

.nav__hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text-primary);
  border-radius: 2px;
  transition: all var(--transition);
}

/* ===========================
   Hero
   =========================== */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  position: relative;
  overflow: hidden;
}

.hero__bg-grid {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(108, 99, 255, 0.08) 1px, transparent 1px),
    linear-gradient(90deg, rgba(108, 99, 255, 0.08) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 30%, transparent 100%);
  pointer-events: none;
}

.hero__container {
  max-width: 1100px;
  margin: 0 auto;
  padding: 0 24px;
  padding-top: var(--nav-height);
}

.hero__greeting {
  font-size: 1rem;
  color: var(--accent);
  font-family: var(--font-mono);
  margin-bottom: 12px;
  font-weight: 500;
}

.hero__name {
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.05;
  margin-bottom: 16px;
}

.hero__cursor {
  display: inline-block;
  width: 4px;
  background: var(--accent);
  animation: blink 1s step-end infinite;
  margin-left: 2px;
  vertical-align: baseline;
}

@keyframes blink {
  0%, 100% { opacity: 1; }
  50% { opacity: 0; }
}

.hero__title {
  font-size: clamp(1.2rem, 3vw, 1.8rem);
  font-weight: 500;
  color: var(--text-secondary);
  margin-bottom: 24px;
  min-height: 2.2rem;
  font-family: var(--font-mono);
}

.hero__title-text {
  background: var(--gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero__desc {
  font-size: 1.05rem;
  color: var(--text-secondary);
  max-width: 480px;
  line-height: 1.8;
  margin-bottom: 40px;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
  margin-bottom: 48px;
}

.hero__socials {
  display: flex;
  gap: 20px;
}

.hero__socials a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 42px;
  height: 42px;
  border-radius: 50%;
  background: var(--bg-card);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: all var(--transition);
}

.hero__socials a:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-3px);
}

.hero__scroll-hint {
  position: absolute;
  bottom: 40px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  color: var(--text-secondary);
  font-size: 0.75rem;
  font-family: var(--font-mono);
  letter-spacing: 0.1em;
  animation: fadeInUp 1s ease 1s both;
}

.hero__scroll-line {
  width: 1px;
  height: 40px;
  background: linear-gradient(to bottom, var(--accent), transparent);
  animation: scrollDown 1.5s ease-in-out infinite;
}

@keyframes scrollDown {
  0% { transform: scaleY(0); transform-origin: top; }
  50% { transform: scaleY(1); transform-origin: top; }
  51% { transform: scaleY(1); transform-origin: bottom; }
  100% { transform: scaleY(0); transform-origin: bottom; }
}

/* ===========================
   About
   =========================== */
.about {
  background: var(--bg-secondary);
}

.about__grid {
  display: grid;
  grid-template-columns: 300px 1fr;
  gap: 64px;
  align-items: start;
}

.about__image-wrap {
  position: sticky;
  top: calc(var(--nav-height) + 24px);
}

.about__image-placeholder {
  width: 100%;
  aspect-ratio: 1;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 5rem;
  color: var(--border);
  overflow: hidden;
}

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

.about__subtitle {
  font-size: 1.3rem;
  font-weight: 700;
  margin-bottom: 16px;
}

.about__text {
  color: var(--text-secondary);
  margin-bottom: 16px;
  font-size: 0.97rem;
}

.about__info-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin: 28px 0;
  padding: 24px;
  background: var(--bg-card);
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

.about__info-item {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.about__info-label {
  font-size: 0.8rem;
  color: var(--text-secondary);
  font-family: var(--font-mono);
  display: flex;
  align-items: center;
  gap: 6px;
}

.about__info-label i { color: var(--accent); }

.about__info-value {
  font-size: 0.9rem;
  font-weight: 600;
}

/* ===========================
   Skills
   =========================== */
.skills__categories {
  display: flex;
  flex-direction: column;
  gap: 48px;
}

.skills__category-title {
  font-size: 1rem;
  font-family: var(--font-mono);
  color: var(--accent);
  margin-bottom: 20px;
  letter-spacing: 0.05em;
}

.skills__grid {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
}

.skill-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 20px 24px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  width: 100px;
  transition: all var(--transition);
  cursor: default;
}

.skill-card:hover {
  border-color: var(--accent);
  transform: translateY(-4px);
  box-shadow: 0 8px 24px rgba(108, 99, 255, 0.15);
}

.skill-card img {
  width: 40px;
  height: 40px;
  filter: drop-shadow(0 1px 2px rgba(0,0,0,0.08));
}

.skill-card span {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-align: center;
}

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

.projects__filter {
  display: flex;
  gap: 10px;
  margin-bottom: 40px;
  flex-wrap: wrap;
}

.filter-btn {
  padding: 8px 20px;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: transparent;
  color: var(--text-secondary);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  font-family: var(--font-main);
}

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

.filter-btn.active {
  background: var(--gradient);
  border-color: transparent;
  color: #fff;
}

.projects__grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: 24px;
}

.project-card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  overflow: hidden;
  transition: all var(--transition);
}

.project-card:hover {
  border-color: var(--accent);
  transform: translateY(-6px);
  box-shadow: var(--shadow);
}

.project-card.hidden {
  display: none;
}

.project-card__image {
  position: relative;
  aspect-ratio: 16/9;
  background: var(--bg-secondary);
  overflow: hidden;
}

.project-card__image-placeholder {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 3rem;
  color: var(--border);
}

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

.project-card__overlay {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  opacity: 0;
  transition: opacity var(--transition);
}

.project-card:hover .project-card__overlay {
  opacity: 1;
}

.project-card__link {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  background: var(--accent);
  color: #fff;
  border-radius: 6px;
  font-size: 0.85rem;
  font-weight: 600;
  transition: background var(--transition);
}

.project-card__link:hover {
  background: var(--accent-hover);
  color: #fff;
}

.project-card__content {
  padding: 20px;
}

.project-card__category {
  font-size: 0.75rem;
  font-family: var(--font-mono);
  color: var(--accent);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
}

.project-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  margin: 8px 0;
}

.project-card__desc {
  font-size: 0.88rem;
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.6;
}

.project-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

/* ===========================
   Contact
   =========================== */
.contact__subtitle {
  color: var(--text-secondary);
  font-size: 1rem;
  margin-top: -40px;
  margin-bottom: 48px;
  max-width: 520px;
}

.contact__grid {
  display: grid;
  grid-template-columns: 1fr 1.6fr;
  gap: 56px;
  align-items: start;
}

.contact__info {
  display: flex;
  flex-direction: column;
  gap: 28px;
}

.contact__info-item {
  display: flex;
  align-items: flex-start;
  gap: 16px;
}

.contact__info-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background: var(--accent-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
  font-size: 1.1rem;
  flex-shrink: 0;
}

.contact__info-item h4 {
  font-size: 0.85rem;
  color: var(--text-secondary);
  margin-bottom: 4px;
  font-family: var(--font-mono);
}

.contact__info-item a,
.contact__info-item span {
  font-size: 0.95rem;
  font-weight: 500;
}

.contact__form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
}

.form-group input,
.form-group textarea {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 12px 16px;
  color: var(--text-primary);
  font-family: var(--font-main);
  font-size: 0.95rem;
  transition: border-color var(--transition);
  resize: vertical;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
  color: var(--border);
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--accent);
}

/* ===========================
   Footer
   =========================== */
.footer {
  padding: 32px 0;
  border-top: 1px solid var(--border);
}

.footer .container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}

.footer__text {
  font-size: 0.88rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}

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

.footer__socials a {
  color: var(--text-secondary);
  font-size: 1.1rem;
  transition: color var(--transition);
}

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

/* ===========================
   Back to Top
   =========================== */
.back-to-top {
  position: fixed;
  bottom: 32px;
  right: 32px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--gradient);
  color: #fff;
  border: none;
  cursor: pointer;
  font-size: 0.9rem;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(108, 99, 255, 0.4);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px);
  transition: all var(--transition);
  z-index: 999;
}

.back-to-top.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 24px rgba(108, 99, 255, 0.5);
}

/* ===========================
   Scroll Animations
   =========================== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

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

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

/* ===========================
   Responsive
   =========================== */
@media (max-width: 900px) {
  .about__grid {
    grid-template-columns: 1fr;
  }

  .about__image-wrap {
    position: static;
    max-width: 240px;
    margin: 0 auto;
  }

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

@media (max-width: 768px) {
  .nav__links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background: rgba(248, 248, 255, 0.97);
    backdrop-filter: blur(12px);
    flex-direction: column;
    padding: 24px;
    gap: 24px;
    border-bottom: 1px solid var(--border);
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition);
  }

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

  .nav__hamburger {
    display: flex;
  }

  .nav__hamburger.open span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
  }

  .nav__hamburger.open span:nth-child(2) {
    opacity: 0;
  }

  .nav__hamburger.open span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
  }

  .section {
    padding: 72px 0;
  }

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

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

  .hero__actions {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer .container {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
}

@media (max-width: 480px) {
  .hero__name {
    font-size: clamp(2.4rem, 10vw, 3.5rem);
  }

  .back-to-top {
    bottom: 20px;
    right: 20px;
  }
}