/* ==========================================
   CSS CUSTOM PROPERTIES — DESIGN TOKENS
========================================== */
:root {
  --bg:           #0A0A0A;
  --surface:      #121212;
  --surface-2:    #1A1A1A;
  --text-primary: #FFFFFF;
  --text-secondary: #C8C8C8;
  --text-muted:   #9E9E9E;
  --accent-start: #00D4FF;
  --accent-end:   #0066FF;
  --accent-grad:  linear-gradient(135deg, #00D4FF, #0066FF);
  --border:       rgba(255,255,255,0.08);
  --border-hover: rgba(255,255,255,0.16);
  --glow:         0 0 40px rgba(0,212,255,0.15);
  --glow-strong:  0 0 60px rgba(0,212,255,0.3);
  --radius-sm:    8px;
  --radius-md:    16px;
  --radius-lg:    24px;
  --radius-xl:    40px;
  --font-display: 'Inter', sans-serif;
  --font-body:    'Inter', sans-serif;
  --nav-h:        72px;
  --transition:   0.3s cubic-bezier(0.4,0,0.2,1);
  --transition-slow: 0.6s cubic-bezier(0.4,0,0.2,1);
}

/* ==========================================
   NAVIGATION
========================================== */
#site-nav {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 1000;
  height: var(--nav-h);
  display: flex; align-items: center;
  transition: background var(--transition), backdrop-filter var(--transition), border-color var(--transition);
  border-bottom: 1px solid transparent;
}
#site-nav.scrolled {
  background: rgba(10,10,10,0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-color: var(--border);
}
.nav-inner {
  display: flex; align-items: center;
  justify-content: space-between;
  width: 100%;
}
.nav-logo {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 800;
  letter-spacing: -0.04em;
  background: var(--accent-grad);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
  flex-shrink: 0;
}
.nav-links {
  display: none;
  gap: 36px;
}
@media (min-width: 1024px) {
  .nav-links { display: flex; align-items: center; }
}
.nav-links a {
  font-size: 0.9rem;
  color: var(--text-secondary);
  transition: color var(--transition);
  font-weight: 500;
}
.nav-links a:hover { color: var(--text-primary); }
.nav-right {
  display: flex; align-items: center; gap: 12px;
}
.nav-cta { display: none; }
@media (min-width: 640px) { .nav-cta { display: inline-flex; } }

/* Hamburger */
.hamburger {
  display: flex; flex-direction: column;
  justify-content: center; align-items: center;
  width: 44px; height: 44px;
  gap: 5px;
  border-radius: var(--radius-sm);
  transition: background var(--transition);
  flex-shrink: 0;
}
.hamburger:hover { background: rgba(255,255,255,0.06); }
.hamburger span {
  display: block; height: 1.5px; border-radius: 2px;
  background: var(--text-primary);
  transition: var(--transition);
  transform-origin: center;
}
.hamburger span:nth-child(1) { width: 22px; }
.hamburger span:nth-child(2) { width: 16px; }
.hamburger span:nth-child(3) { width: 20px; }
.hamburger[aria-expanded="true"] span:nth-child(1) { width: 20px; transform: translateY(6.5px) rotate(45deg); }
.hamburger[aria-expanded="true"] span:nth-child(2) { opacity: 0; transform: scaleX(0); }
.hamburger[aria-expanded="true"] span:nth-child(3) { width: 20px; transform: translateY(-6.5px) rotate(-45deg); }

/* ==========================================
   DRAWER
========================================== */
.drawer-overlay {
  position: fixed; inset: 0; z-index: 1001;
  background: rgba(0,0,0,0.7);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  opacity: 0; pointer-events: none;
  transition: opacity var(--transition);
}
.drawer-overlay.open { opacity: 1; pointer-events: all; }

.drawer {
  position: fixed; top: 0; right: 0; bottom: 0;
  z-index: 1002;
  width: min(360px, 90vw);
  background: rgba(18,18,18,0.95);
  backdrop-filter: blur(40px);
  -webkit-backdrop-filter: blur(40px);
  border-left: 1px solid var(--border);
  display: flex; flex-direction: column;
  padding: 0;
  transform: translateX(100%);
  transition: transform 0.35s cubic-bezier(0.4,0,0.2,1);
}
.drawer.open { transform: translateX(0); }

.drawer-header {
  display: flex; align-items: center;
  justify-content: space-between;
  padding: 0 28px;
  height: var(--nav-h);
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}
.drawer-logo {
  font-family: var(--font-display);
  font-size: 1.4rem; font-weight: 800;
  letter-spacing: -0.04em;
  background: var(--accent-grad);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent; background-clip: text;
}
.drawer-close {
  width: 44px; height: 44px;
  display: flex; align-items: center; justify-content: center;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  transition: var(--transition);
}
.drawer-close:hover { background: rgba(255,255,255,0.06); color: var(--text-primary); }

.drawer-nav {
  flex: 1; overflow-y: auto;
  padding: 24px 0;
}
.drawer-nav::-webkit-scrollbar { width: 4px; }
.drawer-nav::-webkit-scrollbar-track { background: transparent; }
.drawer-nav::-webkit-scrollbar-thumb { background: var(--border); border-radius: 4px; }

.drawer-item {
  display: block;
  font-family: var(--font-display);
  font-size: 1.4rem; font-weight: 700;
  color: var(--text-secondary);
  padding: 14px 28px;
  transition: var(--transition);
  letter-spacing: -0.02em;
  opacity: 0;
  transform: translateX(20px);
  line-height: 1.2;
}
.drawer.open .drawer-item { opacity: 1; transform: translateX(0); }
.drawer.open .drawer-item:nth-child(1) { transition-delay: 0.05s; }
.drawer.open .drawer-item:nth-child(2) { transition-delay: 0.10s; }
.drawer.open .drawer-item:nth-child(3) { transition-delay: 0.15s; }
.drawer.open .drawer-item:nth-child(4) { transition-delay: 0.20s; }
.drawer.open .drawer-item:nth-child(5) { transition-delay: 0.25s; }
.drawer.open .drawer-item:nth-child(6) { transition-delay: 0.30s; }
.drawer.open .drawer-item:nth-child(7) { transition-delay: 0.35s; }
.drawer-item:hover { color: var(--text-primary); transform: translateX(6px); }
.drawer-item.active { color: var(--accent-start); }

/* Accordion */
.drawer-accordion {}
.drawer-accordion-trigger {
  width: 100%;
  display: flex; align-items: center; justify-content: space-between;
  font-family: var(--font-display);
  font-size: 1.4rem; font-weight: 700;
  color: var(--text-secondary);
  padding: 14px 28px;
  transition: var(--transition);
  letter-spacing: -0.02em;
  opacity: 0;
  transform: translateX(20px);
  line-height: 1.2;
}
.drawer.open .drawer-accordion-trigger { opacity: 1; transform: translateX(0); }
.drawer-accordion-trigger:hover { color: var(--text-primary); }
.drawer-accordion-trigger[aria-expanded="true"] { color: var(--accent-start); }
.drawer-accordion-trigger .chevron {
  width: 20px; height: 20px;
  transition: transform var(--transition);
  flex-shrink: 0; opacity: 0.5;
}
.drawer-accordion-trigger[aria-expanded="true"] .chevron { transform: rotate(180deg); opacity: 1; }
.drawer-accordion-body {
  max-height: 0; overflow: hidden;
  transition: max-height 0.35s cubic-bezier(0.4,0,0.2,1);
}
.drawer-accordion-body.open { max-height: 300px; }
.drawer-sub-item {
  display: flex; align-items: center; gap: 10px;
  font-size: 0.95rem; font-weight: 400;
  color: var(--text-muted);
  padding: 10px 28px 10px 42px;
  transition: var(--transition);
}
.drawer-sub-item::before {
  content: ''; width: 4px; height: 4px; border-radius: 50%;
  background: var(--accent-start); opacity: 0.5; flex-shrink: 0;
}
.drawer-sub-item:hover { color: var(--text-primary); }
.drawer-sub-item:hover::before { opacity: 1; }

.drawer-footer {
  padding: 20px 24px 28px;
  border-top: 1px solid var(--border); flex-shrink: 0;
}
.drawer-footer .btn {
  width: 100%; height: 56px; font-size: 0.95rem;
  box-shadow: 0 0 40px rgba(0,212,255,0.2);
}
.drawer-footer .btn:hover { box-shadow: 0 0 60px rgba(0,212,255,0.4); }

/* ==========================================
   CUSTOM CURSOR (DESKTOP)
========================================== */
@media (pointer: fine) {
  body { cursor: none; }
  a, button { cursor: none; }
}
.cursor {
  display: none;
}
@media (pointer: fine) {
  .cursor {
    display: block;
    position: fixed; z-index: 99999;
    pointer-events: none;
    top: 0; left: 0;
  }
  .cursor-dot {
    width: 8px; height: 8px; border-radius: 50%;
    background: var(--accent-start);
    position: absolute;
    transform: translate(-50%,-50%);
    transition: transform 0.1s, width 0.2s, height 0.2s, opacity 0.2s;
  }
  .cursor-ring {
    width: 36px; height: 36px; border-radius: 50%;
    border: 1px solid rgba(0,212,255,0.4);
    position: absolute;
    transform: translate(-50%,-50%);
    transition: transform 0.12s ease-out, width 0.3s, height 0.3s, border-color 0.3s;
  }
  body.cursor-hover .cursor-dot { width: 12px; height: 12px; }
  body.cursor-hover .cursor-ring {
    width: 56px; height: 56px;
    border-color: rgba(0,212,255,0.6);
  }
}

/* ==========================================
   GO-TO-TOP BUTTON
========================================== */
#go-top-btn {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 999999;
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: linear-gradient(135deg, #00D4FF, #0066FF);
  color: #fff;
  border: none;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 24px rgba(0,212,255,0.5), 0 4px 20px rgba(0,0,0,0.5);
  opacity: 0;
  visibility: hidden;
  transform: translateY(16px) scale(0.85);
  transition: opacity 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease, visibility 0.3s;
}
#go-top-btn.visible {
  opacity: 1;
  visibility: visible;
  transform: translateY(0) scale(1);
}
#go-top-btn:hover {
  box-shadow: 0 0 48px rgba(0,212,255,0.7), 0 6px 24px rgba(0,0,0,0.5);
  transform: translateY(-3px) scale(1.08);
}
#go-top-btn:active {
  transform: translateY(0) scale(0.96);
}
@media (max-width: 640px) {
  #go-top-btn { bottom: 20px; right: 20px; width: 46px; height: 46px; }
}