/* ══════════════════════════════════════════════════════════════════════════
   VARIABLES
   ══════════════════════════════════════════════════════════════════════════ */
:root {
  --bg:            #07080f;
  --bg-soft:       #0b0d18;
  --surface:       #11121f;
  --surface-2:     #161829;
  --surface-glass: rgba(255, 255, 255, 0.035);
  --border:        rgba(255, 255, 255, 0.09);
  --border-strong: rgba(255, 255, 255, 0.18);
  --text:          #edeff8;
  --muted:         #8991ac;
  --muted-2:       #666f8c;
  --accent:        #8b6cf2;
  --accent-2:      #5b8cff;
  --accent-rgb:    139, 108, 242;
  --radius:        12px;
  --radius-sm:     8px;
  --max-w:         1120px;
  --nav-h:         68px;
  --transition:    0.25s cubic-bezier(0.22, 1, 0.36, 1);
  --ease-spring:   cubic-bezier(0.34, 1.56, 0.64, 1);
}

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

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

body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  line-height: 1.65;
  position: relative;
  overflow-x: hidden;
}

a { color: var(--accent-2); text-decoration: none; }

::selection { background: rgba(var(--accent-rgb), 0.35); color: #fff; }

:focus-visible {
  outline: 2px solid var(--accent-2);
  outline-offset: 3px;
  border-radius: 4px;
}

/* ══════════════════════════════════════════════════════════════════════════
   BACKGROUND EFFECTS — fixed layered depth behind all content
   ══════════════════════════════════════════════════════════════════════════ */
.bg-layer {
  position: fixed;
  inset: 0;
  z-index: 0;
  overflow: hidden;
  pointer-events: none;
  background: var(--bg);
}

.bg-grid {
  position: absolute;
  inset: -10% -10%;
  background-image:
    linear-gradient(rgba(255,255,255,0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,0.035) 1px, transparent 1px);
  background-size: 56px 56px;
  mask-image: radial-gradient(ellipse 70% 60% at 50% 20%, #000 40%, transparent 85%);
  animation: gridDrift 40s linear infinite;
}
@keyframes gridDrift {
  from { transform: translate(0, 0); }
  to   { transform: translate(56px, 56px); }
}

@media (prefers-reduced-motion: reduce) {
  .bg-grid { animation: none; }
}

/* ══════════════════════════════════════════════════════════════════════════
   SCROLL PROGRESS BAR
   ══════════════════════════════════════════════════════════════════════════ */
.scroll-progress {
  position: fixed;
  top: 0; left: 0;
  height: 2.5px;
  width: 100%;
  background: linear-gradient(90deg, var(--accent-2), var(--accent));
  transform: scaleX(0);
  transform-origin: left;
  z-index: 300;
  will-change: transform;
}

/* ══════════════════════════════════════════════════════════════════════════
   NAVIGATION
   ══════════════════════════════════════════════════════════════════════════ */
#navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: var(--nav-h);
  z-index: 200;
  background: transparent;
  border-bottom: 1px solid transparent;
  transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
}
#navbar.scrolled {
  background: rgba(7, 8, 15, 0.72);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-color: var(--border);
  box-shadow: 0 8px 30px -12px rgba(0,0,0,0.5);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2rem;
}

.nav-logo {
  font-weight: 800;
  font-size: 1.05rem;
  letter-spacing: 0.06em;
  color: var(--text);
  background: linear-gradient(120deg, var(--text) 30%, var(--accent-2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.nav-menu {
  display: flex;
  align-items: center;
  gap: 2rem;
}

.nav-links-wrap { position: relative; }
.nav-links {
  list-style: none;
  display: flex;
  gap: 0.4rem;
}
.nav-links a {
  position: relative;
  display: inline-block;
  color: var(--muted);
  font-size: 0.85rem;
  font-weight: 500;
  letter-spacing: 0.02em;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  transition: color var(--transition);
  z-index: 1;
}
.nav-links a:hover { color: var(--text); }
.nav-links a.active { color: var(--text); }

.nav-pill {
  position: absolute;
  top: 0; left: 0;
  height: 100%;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: 999px;
  transition: left var(--transition), width var(--transition), opacity var(--transition);
  opacity: 0;
  pointer-events: none;
}
.nav-pill.visible { opacity: 1; }

/* Hamburger (mobile only) */
.nav-toggle {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 36px;
  height: 36px;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  padding: 0;
}
.nav-toggle-bar {
  display: block;
  width: 16px;
  height: 1.5px;
  margin: 0 auto;
  background: var(--text);
  border-radius: 2px;
  transition: transform 0.3s var(--ease-spring), opacity 0.2s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(6.5px) 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(-6.5px) rotate(-45deg); }

/* ── Language Switcher: single-tap toggle ── */
.lang-toggle {
  display: flex;
  align-items: center;
  gap: 0.3rem;
  background: var(--surface-glass);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--muted);
  cursor: pointer;
  font-size: 0.78rem;
  font-weight: 600;
  font-family: inherit;
  padding: 0.3rem 0.55rem;
  transition: color var(--transition), border-color var(--transition), transform var(--transition);
  white-space: nowrap;
}
.lang-toggle:hover { color: var(--text); border-color: var(--accent-2); }
.lang-toggle:active { transform: scale(0.95); }
.lang-toggle .globe { font-size: 0.9rem; line-height: 1; }

@media (max-width: 700px) {
  .nav-toggle { display: flex; }
  .nav-menu {
    position: fixed;
    top: var(--nav-h);
    left: 0; right: 0;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    background: rgba(9, 10, 19, 0.97);
    backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border);
    padding: 0.5rem 1.5rem 1.25rem;
    max-height: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height var(--transition), opacity var(--transition);
  }
  .nav-menu.open { max-height: 90vh; opacity: 1; overflow-y: auto; }
  .nav-links { flex-direction: column; gap: 0.2rem; }
  .nav-links a { padding: 0.75rem 0.5rem; width: 100%; }
  .nav-pill { display: none; }
  .lang-toggle { margin-top: 0.75rem; align-self: flex-start; }
}

/* ══════════════════════════════════════════════════════════════════════════
   HERO / INTRO (name + about side by side)
   ══════════════════════════════════════════════════════════════════════════ */
.intro-section {
  position: relative;
  padding-top: calc(var(--nav-h) + 3rem);
  z-index: 1;
}
.intro-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}
.intro-name,
.intro-about {
  min-width: 0; /* grid items default to min-width:auto, which lets long
                   unbreakable text runs (e.g. mixed Latin/CJK) push the
                   track wider than the viewport instead of wrapping */
}
.intro-name { padding-top: 0.5rem; }

.reveal-up {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s ease, transform 0.7s var(--ease-spring);
}
.reveal-up.in-view { opacity: 1; transform: translateY(0); }
.intro-name .reveal-up:nth-child(1) { transition-delay: 0.05s; }
.intro-name .reveal-up:nth-child(2) { transition-delay: 0.15s; }
.intro-name .reveal-up:nth-child(3) { transition-delay: 0.25s; }
.intro-name .reveal-up:nth-child(4) { transition-delay: 0.35s; }

.hero-name {
  font-size: clamp(2.4rem, 6.5vw, 4.2rem);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 0.5rem;
}
.hero-name .accent-word {
  background: linear-gradient(120deg, var(--accent-2), var(--accent));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.hero-title {
  font-size: clamp(0.95rem, 2vw, 1.15rem);
  color: var(--muted);
  font-weight: 500;
  letter-spacing: 0.02em;
  margin-bottom: 1.1rem;
}
.hero-sub {
  max-width: 460px;
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 2rem;
  overflow-wrap: break-word;
}

.hero-cta { display: flex; gap: 0.85rem; flex-wrap: wrap; margin-bottom: 1.5rem; }

.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius-sm);
  font-size: 0.875rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: transform var(--transition), box-shadow var(--transition),
              border-color var(--transition), background var(--transition), color var(--transition);
  border: 1px solid transparent;
  letter-spacing: 0.01em;
  overflow: hidden;
}
.btn .arrow { transition: transform var(--transition); }
.btn:hover .arrow { transform: translateX(3px); }
.btn:active { transform: scale(0.97); }

.btn-primary {
  background: linear-gradient(120deg, var(--accent-2), var(--accent));
  color: #fff;
  box-shadow: 0 8px 24px -8px rgba(var(--accent-rgb), 0.55);
}
.btn-primary:hover { box-shadow: 0 12px 32px -8px rgba(var(--accent-rgb), 0.75); transform: translateY(-2px); }

.btn-outline {
  border-color: var(--border-strong);
  color: var(--text);
  background: var(--surface-glass);
}
.btn-outline:hover { border-color: var(--accent-2); color: var(--accent-2); transform: translateY(-2px); }

/* ══════════════════════════════════════════════════════════════════════════
   SECTIONS (shared)
   ══════════════════════════════════════════════════════════════════════════ */
.section     { position: relative; padding: 6rem 2rem; z-index: 1; }
.section-alt { background: linear-gradient(180deg, transparent, rgba(255,255,255,0.015) 20%, transparent 80%); }

.container { max-width: var(--max-w); margin: 0 auto; }

.section-title {
  font-size: 0.8rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.16em;
  color: var(--muted);
  margin-bottom: 2.5rem;
  display: flex;
  align-items: center;
  gap: 1rem;
}
.section-title::before {
  content: "";
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent-2);
  box-shadow: 0 0 10px 2px rgba(var(--accent-rgb), 0.6);
  flex-shrink: 0;
}
.section-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, var(--border), transparent);
  display: block;
}

/* ══════════════════════════════════════════════════════════════════════════
   ABOUT
   ══════════════════════════════════════════════════════════════════════════ */
.about-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  align-items: start;
  min-width: 0;
}
.about-text { min-width: 0; }
.about-text p {
  color: var(--muted);
  margin-bottom: 1rem;
  font-size: 0.975rem;
  max-width: 60ch;
  overflow-wrap: break-word;
}

.about-facts { display: flex; flex-direction: column; gap: 0; }
.fact {
  display: flex;
  gap: 1.5rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--border);
  transition: padding-left var(--transition), border-color var(--transition);
}
.fact:first-child { border-top: 1px solid var(--border); }
.fact:hover { padding-left: 0.4rem; border-color: var(--border-strong); }
.fact-label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted-2);
  min-width: 80px;
}
.fact-value {
  font-size: 0.92rem;
  color: var(--text);
}

/* ══════════════════════════════════════════════════════════════════════════
   PROJECT CARDS
   ══════════════════════════════════════════════════════════════════════════ */
.projects-grid {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}
.project-card {
  --entry: 24px;
  position: relative;
  display: flex;
  align-items: flex-start;
  gap: 1.25rem;
  padding: 1.5rem;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-glass);
  opacity: 0;
  transform: translateY(var(--entry));
  transition: transform 0.6s var(--ease-spring), opacity 0.6s ease,
              border-color 0.35s ease, background 0.35s ease;
  overflow: hidden;
}
.project-card.in-view { opacity: 1; --entry: 0px; }
.project-card:nth-of-type(1) { transition-delay: 0s, 0s, 0s, 0s; }
.project-card:nth-of-type(2) { transition-delay: 0.09s, 0.09s, 0s, 0s; }
.project-card:nth-of-type(3) { transition-delay: 0.18s, 0.18s, 0s, 0s; }
.project-card:nth-of-type(4) { transition-delay: 0.27s, 0.27s, 0s, 0s; }

.project-card:hover,
.project-card:focus-within {
  border-color: hsl(var(--hue) 70% 60% / 0.5);
  background: hsl(var(--hue) 60% 50% / 0.06);
}

/* Pointer-following glow highlight (no rotation/movement of the card itself) */
.project-glow {
  position: absolute;
  inset: 0;
  opacity: 0;
  background: radial-gradient(260px circle at var(--gx, 50%) var(--gy, 50%),
              hsl(var(--hue) 80% 65% / 0.14), transparent 60%);
  transition: opacity 0.3s ease;
  pointer-events: none;
}
.project-card:hover .project-glow { opacity: 1; }

.project-body {
  flex: 1;
  min-width: 0;
  display: grid;
  gap: 0.4rem;
  position: relative;
}
.project-icon {
  flex-shrink: 0;
  width: 60px;
  height: 60px;
  position: relative;
  filter: drop-shadow(0 6px 14px hsl(var(--hue) 60% 45% / 0.4));
}
.project-icon svg {
  display: block;
  transition: transform 0.35s ease;
}
.project-card:hover .project-icon svg { transform: scale(1.08); }

.project-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  flex-wrap: wrap;
}
.project-header h3 {
  font-size: 1rem;
  font-weight: 700;
  color: var(--text);
  transition: color var(--transition);
}
.project-card:hover .project-header h3 { color: hsl(var(--hue) 75% 72%); }

.project-tag {
  font-size: 0.68rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  color: hsl(var(--hue) 80% 78%);
  background: hsl(var(--hue) 70% 50% / 0.14);
  border: 1px solid hsl(var(--hue) 70% 55% / 0.3);
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  white-space: nowrap;
}

.project-card p {
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.6;
}

.project-links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-top: 0.35rem;
}
.project-link {
  display: inline-flex;
  align-items: center;
  gap: 0.3rem;
  font-size: 0.72rem;
  font-weight: 700;
  color: hsl(var(--hue) 80% 75%);
  background: hsl(var(--hue) 70% 50% / 0.1);
  border: 1px solid hsl(var(--hue) 70% 55% / 0.28);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  padding: 0.4rem 0.8rem;
  border-radius: 999px;
  transition: background var(--transition), color var(--transition),
              border-color var(--transition), transform var(--transition);
}
.project-link:hover {
  background: hsl(var(--hue) 65% 50%);
  border-color: hsl(var(--hue) 65% 50%);
  color: #0a0a12;
  text-decoration: none;
  transform: translateY(-1px);
}

@media (max-width: 700px) {
  .project-card { flex-direction: column; padding: 1.25rem; }
  .project-icon { width: 48px; height: 48px; }
  .project-icon svg { width: 48px; height: 48px; }
}

@media (prefers-reduced-motion: reduce) {
  .project-card { opacity: 1; transform: none; transition: border-color 0.3s ease; }
  .reveal-up { opacity: 1; transform: none; transition: none; }
}

/* ══════════════════════════════════════════════════════════════════════════
   CONTACT
   ══════════════════════════════════════════════════════════════════════════ */
.contact-container { max-width: 640px; }
.contact-sub {
  color: var(--muted);
  font-size: 0.95rem;
  margin-bottom: 2rem;
  margin-top: -1.5rem;
}

.contact-card {
  position: relative;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface-glass);
  padding: 2rem;
  overflow: hidden;
}
.contact-card::before {
  content: "";
  position: absolute;
  inset: -1px;
  border-radius: inherit;
  padding: 1px;
  background: linear-gradient(140deg, rgba(var(--accent-rgb), 0.45), transparent 40%, transparent 70%, rgba(91,140,255,0.35));
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor;
  mask-composite: exclude;
  pointer-events: none;
}

.contact-form { display: flex; flex-direction: column; gap: 1.15rem; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 1.1rem; }

.form-group { display: flex; flex-direction: column; gap: 0.4rem; }
.form-group label {
  font-size: 0.7rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--muted-2);
}

.form-group input,
.form-group textarea {
  background: rgba(255,255,255,0.03);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  color: var(--text);
  font-size: 0.925rem;
  font-family: inherit;
  padding: 0.65rem 0.8rem;
  outline: none;
  transition: border-color var(--transition), background var(--transition);
  resize: vertical;
}
.form-group input::placeholder,
.form-group textarea::placeholder { color: var(--muted-2); }
.form-group input:focus,
.form-group textarea:focus { border-color: var(--accent-2); background: rgba(255,255,255,0.05); }

.form-status {
  font-size: 0.85rem;
  color: var(--accent-2);
  min-height: 1.2em;
}

.contact-links {
  margin-top: 2rem;
  display: flex;
  gap: 0.75rem;
  flex-wrap: wrap;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
}
.contact-links a {
  display: inline-flex;
  align-items: center;
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 600;
  border: 1px solid var(--border);
  border-radius: 999px;
  padding: 0.45rem 0.95rem;
  transition: color var(--transition), border-color var(--transition), transform var(--transition);
}
.contact-links a:hover {
  color: var(--text);
  border-color: var(--accent-2);
  text-decoration: none;
  transform: translateY(-1px);
}

/* ══════════════════════════════════════════════════════════════════════════
   FOOTER
   ══════════════════════════════════════════════════════════════════════════ */
footer {
  position: relative;
  z-index: 1;
  text-align: center;
  padding: 2.5rem 2rem;
  color: var(--muted-2);
  font-size: 0.8rem;
  border-top: 1px solid var(--border);
  letter-spacing: 0.02em;
}

.back-to-top {
  position: fixed;
  right: 1.5rem;
  bottom: 1.5rem;
  width: 42px;
  height: 42px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 50%;
  color: var(--text);
  cursor: pointer;
  z-index: 150;
  opacity: 0;
  transform: translateY(10px) scale(0.9);
  pointer-events: none;
  transition: opacity var(--transition), transform var(--transition), border-color var(--transition);
}
.back-to-top.visible { opacity: 1; transform: translateY(0) scale(1); pointer-events: auto; }
.back-to-top:hover { border-color: var(--accent-2); color: var(--accent-2); }

/* ══════════════════════════════════════════════════════════════════════════
   REVEAL ANIMATION VARIANTS (about facts, contact card)
   ══════════════════════════════════════════════════════════════════════════ */
.reveal-scale {
  opacity: 0;
  transform: scale(0.96);
  transition: opacity 0.6s ease, transform 0.6s var(--ease-spring);
}
.reveal-scale.in-view { opacity: 1; transform: scale(1); }

.reveal-line {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.5s ease, transform 0.5s ease;
}
.reveal-line.in-view { opacity: 1; transform: translateY(0); }
.about-facts .fact:nth-child(1) { transition-delay: 0.05s; }
.about-facts .fact:nth-child(2) { transition-delay: 0.12s; }
.about-facts .fact:nth-child(3) { transition-delay: 0.19s; }

@media (prefers-reduced-motion: reduce) {
  .reveal-scale, .reveal-line { opacity: 1; transform: none; transition: none; }
}

/* ══════════════════════════════════════════════════════════════════════════
   RESPONSIVE
   ══════════════════════════════════════════════════════════════════════════ */
@media (min-width: 1440px) {
  :root { --max-w: 1280px; }
}
@media (min-width: 1800px) {
  :root { --max-w: 1440px; }
  .bg-grid { background-size: 64px 64px; }
}
@media (max-width: 700px) {
  .intro-grid { grid-template-columns: 1fr; gap: 2.5rem; }
  .about-grid { grid-template-columns: 1fr; gap: 2rem; }
  .form-row   { grid-template-columns: 1fr; }
  .section    { padding: 4.5rem 1.25rem; }
  .contact-card { padding: 1.5rem; }
  .back-to-top { right: 1rem; bottom: 1rem; width: 38px; height: 38px; }
}
@media (max-width: 480px) {
  #lang-current { display: none; }
}