:root {
  --bg: #07070c;
  --bg-soft: #0d0d16;
  --surface: rgba(255, 255, 255, 0.035);
  --surface-strong: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.16);
  --text: #ececf4;
  --text-dim: #9a9ab0;
  --text-faint: #6a6a80;
  --accent-1: #7c5cff;
  --accent-2: #22d3ee;
  --accent-3: #f472b6;
  --gradient: linear-gradient(120deg, var(--accent-1), var(--accent-2));
  --radius: 18px;
  --radius-sm: 12px;
  --maxw: 1120px;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 90px;
}

body {
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

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

ul {
  list-style: none;
}

.container {
  width: min(var(--maxw), calc(100% - 48px));
  margin-inline: auto;
}

/* ---------- background ---------- */
.bg-orbs {
  position: fixed;
  inset: 0;
  z-index: -1;
  overflow: hidden;
}

.orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(90px);
  opacity: 0.5;
  animation: float 18s ease-in-out infinite;
}

.orb-1 {
  width: 520px;
  height: 520px;
  background: radial-gradient(circle, rgba(124, 92, 255, 0.55), transparent 70%);
  top: -160px;
  left: -120px;
}

.orb-2 {
  width: 480px;
  height: 480px;
  background: radial-gradient(circle, rgba(34, 211, 238, 0.42), transparent 70%);
  top: 20%;
  right: -180px;
  animation-delay: -6s;
}

.orb-3 {
  width: 460px;
  height: 460px;
  background: radial-gradient(circle, rgba(244, 114, 182, 0.32), transparent 70%);
  bottom: -180px;
  left: 30%;
  animation-delay: -12s;
}

@keyframes float {
  0%, 100% { transform: translate3d(0, 0, 0) scale(1); }
  50% { transform: translate3d(30px, -40px, 0) scale(1.08); }
}

.grid-overlay {
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.028) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.028) 1px, transparent 1px);
  background-size: 64px 64px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
}

/* ---------- header ---------- */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  transition: background 0.3s var(--ease), border-color 0.3s var(--ease), backdrop-filter 0.3s;
  border-bottom: 1px solid transparent;
}

.site-header.scrolled {
  background: rgba(7, 7, 12, 0.72);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom-color: var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

.logo {
  font-weight: 800;
  font-size: 1.15rem;
  letter-spacing: -0.02em;
}

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

.nav-links {
  display: flex;
  align-items: center;
  gap: 8px;
}

.nav-link {
  padding: 8px 14px;
  border-radius: 999px;
  font-size: 0.92rem;
  color: var(--text-dim);
  transition: color 0.2s, background 0.2s;
}

.nav-link:hover,
.nav-link.active {
  color: var(--text);
  background: var(--surface-strong);
}

.nav-cta {
  margin-left: 8px;
  padding: 9px 18px;
  border-radius: 999px;
  font-size: 0.9rem;
  font-weight: 600;
  color: #fff;
  background: var(--gradient);
  box-shadow: 0 8px 24px -10px rgba(124, 92, 255, 0.9);
  transition: transform 0.2s var(--ease), box-shadow 0.2s;
}

.nav-cta:hover {
  transform: translateY(-2px);
  box-shadow: 0 14px 30px -10px rgba(124, 92, 255, 1);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: 0;
  cursor: pointer;
  padding: 8px;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s var(--ease), opacity 0.3s;
}

.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: 110px 0;
  position: relative;
}

.section-eyebrow {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.82rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent-2);
  margin-bottom: 14px;
}

.section-title {
  font-size: clamp(1.7rem, 4vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.03em;
  margin-bottom: 48px;
  max-width: 20ch;
}

/* ---------- hero ---------- */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding-top: 130px;
}

.hero-inner {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 60px;
  align-items: center;
  width: 100%;
}

.hero-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-size: 0.88rem;
  color: var(--text-dim);
  padding: 7px 15px;
  border: 1px solid var(--border);
  border-radius: 999px;
  background: var(--surface);
  margin-bottom: 26px;
}

.status-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: #34d399;
  box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.6);
  animation: pulse 2.2s infinite;
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0.55); }
  70% { box-shadow: 0 0 0 9px rgba(52, 211, 153, 0); }
  100% { box-shadow: 0 0 0 0 rgba(52, 211, 153, 0); }
}

.hero-title {
  font-size: clamp(2.4rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.04em;
  margin-bottom: 22px;
}

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

.hero-subtitle {
  font-size: 1.08rem;
  color: var(--text-dim);
  max-width: 46ch;
  margin-bottom: 34px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  margin-bottom: 38px;
}

.hero-actions.center {
  justify-content: center;
  margin-bottom: 0;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 13px 26px;
  border-radius: 999px;
  font-weight: 600;
  font-size: 0.95rem;
  transition: transform 0.2s var(--ease), box-shadow 0.2s, background 0.2s, border-color 0.2s;
}

.btn-primary {
  color: #fff;
  background: var(--gradient);
  box-shadow: 0 14px 34px -14px rgba(124, 92, 255, 0.95);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 20px 40px -14px rgba(124, 92, 255, 1);
}

.btn-ghost {
  color: var(--text);
  border: 1px solid var(--border-strong);
  background: var(--surface);
}

.btn-ghost:hover {
  background: var(--surface-strong);
  transform: translateY(-2px);
}

.hero-socials {
  display: flex;
  gap: 12px;
}

.social-link {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  border: 1px solid var(--border);
  color: var(--text-dim);
  background: var(--surface);
  transition: color 0.2s, border-color 0.2s, transform 0.2s var(--ease), background 0.2s;
}

.social-link:hover {
  color: var(--text);
  border-color: var(--accent-1);
  background: var(--surface-strong);
  transform: translateY(-3px);
}

/* code card */
.hero-visual {
  perspective: 1200px;
}

.code-card {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: linear-gradient(160deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.02));
  backdrop-filter: blur(12px);
  box-shadow: 0 40px 80px -40px rgba(0, 0, 0, 0.9);
  overflow: hidden;
  transform: rotateY(-8deg) rotateX(4deg);
  transition: transform 0.6s var(--ease);
}

.code-card:hover {
  transform: rotateY(0) rotateX(0) translateY(-6px);
}

.code-card-bar {
  display: flex;
  align-items: center;
  gap: 7px;
  padding: 13px 16px;
  border-bottom: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.03);
}

.dot {
  width: 11px;
  height: 11px;
  border-radius: 50%;
}
.dot.red { background: #ff5f57; }
.dot.yellow { background: #febc2e; }
.dot.green { background: #28c840; }

.code-file {
  margin-left: auto;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.76rem;
  color: var(--text-faint);
}

.code-body {
  padding: 22px 22px 26px;
  font-family: "JetBrains Mono", monospace;
  font-size: 0.86rem;
  line-height: 1.9;
  overflow-x: auto;
}

.c-key { color: #c792ea; }
.c-var { color: #82aaff; }
.c-prop { color: #7fdbca; }
.c-str { color: #c3e88d; }
.c-num { color: #f78c6c; }
.c-fn { color: #82aaff; }

.scroll-hint {
  position: absolute;
  bottom: 36px;
  left: 50%;
  transform: translateX(-50%);
  width: 26px;
  height: 42px;
  border: 2px solid var(--border-strong);
  border-radius: 14px;
  display: grid;
  place-items: start center;
  padding-top: 7px;
}

.scroll-hint span {
  width: 3px;
  height: 8px;
  border-radius: 2px;
  background: var(--accent-2);
  animation: scrollDot 1.8s infinite;
}

@keyframes scrollDot {
  0% { opacity: 0; transform: translateY(0); }
  40% { opacity: 1; }
  100% { opacity: 0; transform: translateY(14px); }
}

/* ---------- about ---------- */
.about-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 60px;
  align-items: start;
}

.about-text p {
  color: var(--text-dim);
  margin-bottom: 18px;
  font-size: 1.02rem;
}

.about-text strong {
  color: var(--text);
}

.stats {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 16px;
}

.stat {
  padding: 26px 22px;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  background: var(--surface);
  transition: border-color 0.3s, transform 0.3s var(--ease);
}

.stat:hover {
  border-color: var(--border-strong);
  transform: translateY(-4px);
}

.stat-num {
  display: block;
  font-size: 2.1rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.stat-label {
  font-size: 0.86rem;
  color: var(--text-faint);
}

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

/* ---------- skills ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.skill-card {
  padding: 30px 26px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  transition: transform 0.35s var(--ease), border-color 0.35s, background 0.35s;
}

.skill-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-strong);
  background: var(--surface-strong);
}

.skill-icon {
  font-size: 1.7rem;
  margin-bottom: 16px;
}

.skill-card h3 {
  font-size: 1.18rem;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.skill-card p {
  color: var(--text-dim);
  font-size: 0.93rem;
  margin-bottom: 18px;
}

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.tags li {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.74rem;
  padding: 5px 11px;
  border-radius: 999px;
  color: var(--text-dim);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}

/* ---------- projects ---------- */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 22px;
}

.project-card {
  position: relative;
  padding: 30px 28px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: transform 0.35s var(--ease), border-color 0.35s, background 0.35s;
}

.project-card::before {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(500px circle at var(--mx, 50%) var(--my, 0%), rgba(124, 92, 255, 0.14), transparent 45%);
  opacity: 0;
  transition: opacity 0.35s;
  pointer-events: none;
}

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

.project-card:hover {
  transform: translateY(-6px);
  border-color: var(--border-strong);
  background: var(--surface-strong);
}

.project-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 18px;
}

.project-icon {
  font-size: 1.6rem;
}

.project-links a {
  color: var(--text-dim);
  font-size: 1.2rem;
  transition: color 0.2s, transform 0.2s;
}

.project-links a:hover {
  color: var(--accent-2);
}

.project-card h3 {
  font-size: 1.2rem;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.project-card > p {
  color: var(--text-dim);
  font-size: 0.94rem;
  margin-bottom: 20px;
}

.project-status {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.72rem;
  letter-spacing: 0.06em;
  padding: 4px 11px;
  border-radius: 999px;
  color: var(--accent-2);
  border: 1px solid rgba(34, 211, 238, 0.3);
  background: rgba(34, 211, 238, 0.08);
}

.project-link {
  display: inline-block;
  margin-top: 20px;
  font-size: 0.88rem;
  font-weight: 600;
  background: var(--gradient);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  transition: opacity 0.2s;
}

.project-link:hover {
  opacity: 0.75;
}

/* ---------- writing ---------- */
.writing-list {
  display: grid;
  gap: 4px;
}

.writing-item a {
  display: grid;
  grid-template-columns: 118px 1fr auto;
  align-items: center;
  gap: 20px;
  padding: 20px 20px;
  border-radius: var(--radius-sm);
  border: 1px solid transparent;
  transition: background 0.25s, border-color 0.25s, transform 0.25s var(--ease);
}

.writing-item a:hover {
  background: var(--surface);
  border-color: var(--border);
  transform: translateX(6px);
}

.writing-date {
  font-family: "JetBrains Mono", monospace;
  font-size: 0.8rem;
  color: var(--text-faint);
}

.writing-title {
  font-size: 1.02rem;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.writing-tag {
  font-size: 0.74rem;
  padding: 5px 11px;
  border-radius: 999px;
  white-space: nowrap;
  color: var(--text-dim);
  border: 1px solid var(--border);
  background: rgba(255, 255, 255, 0.02);
}

.writing-more {
  margin-top: 34px;
  text-align: center;
}

/* ---------- contact ---------- */
.contact-card {
  text-align: center;
  padding: 70px 40px;
  border: 1px solid var(--border);
  border-radius: 28px;
  background:
    radial-gradient(600px circle at 50% -20%, rgba(124, 92, 255, 0.22), transparent 60%),
    var(--surface);
}

.contact-card .section-eyebrow {
  display: block;
}

.contact-card .section-title {
  margin-inline: auto;
  text-align: center;
}

.contact-text {
  color: var(--text-dim);
  max-width: 52ch;
  margin: 0 auto 34px;
}

/* ---------- footer ---------- */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 30px 0;
}

.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: 0.86rem;
  color: var(--text-faint);
}

.back-top {
  color: var(--text-dim);
  transition: color 0.2s;
}

.back-top:hover {
  color: var(--accent-2);
}

/* ---------- reveal ---------- */
.reveal {
  opacity: 0;
  transform: translateY(26px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.reveal.visible {
  opacity: 1;
  transform: none;
}

/* ---------- responsive ---------- */
@media (max-width: 900px) {
  .hero-inner,
  .about-grid {
    grid-template-columns: 1fr;
    gap: 44px;
  }

  .hero {
    padding-top: 120px;
    min-height: auto;
  }

  .code-card {
    transform: none;
  }

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

  .scroll-hint {
    display: none;
  }

  .nav-toggle {
    display: flex;
  }

  .nav-links {
    position: fixed;
    inset: 72px 0 auto 0;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    padding: 16px 24px 26px;
    background: rgba(7, 7, 12, 0.96);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid var(--border);
    transform: translateY(-140%);
    transition: transform 0.4s var(--ease);
  }

  .nav-links.open {
    transform: translateY(0);
  }

  .nav-link {
    padding: 12px 10px;
  }

  .nav-cta {
    margin: 8px 0 0;
    text-align: center;
  }
}

@media (max-width: 620px) {
  .section {
    padding: 80px 0;
  }

  .projects-grid,
  .stats {
    grid-template-columns: 1fr;
  }

  .writing-item a {
    grid-template-columns: 1fr;
    gap: 6px;
    align-items: start;
  }

  .writing-tag {
    justify-self: start;
    margin-top: 6px;
  }

  .footer-inner {
    flex-direction: column;
    gap: 12px;
    text-align: center;
  }
}

@media (prefers-reduced-motion: reduce) {
  * {
    animation: none !important;
    transition: none !important;
  }
  .reveal {
    opacity: 1;
    transform: none;
  }
}