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

/* ── ROOT: DARK (default) ── */
:root {
  --bg: #060c14;
  --bg2: #0a1220;
  --bg3: #0d1829;
  --cyan: #22d3ee;
  --cyan-dark: #06b6d4;
  --cyan-glow: rgba(34,211,238,0.15);
  --white: #ffffff;
  --gray: #94a3b8;
  --gray-dark: #475569;
  --border: rgba(255,255,255,0.07);
  --card-bg: rgba(255,255,255,0.03);
  --nav-bg: rgba(6,12,20,0.9);
  --nav-bg-mobile: rgba(6,12,20,0.97);
}

/* ── LIGHT MODE: manual toggle ── */
[data-theme="light"] {
  --bg: #f0f4f8;
  --bg2: #e2e8f0;
  --bg3: #cbd5e1;
  --white: #0f172a;
  --gray: #475569;
  --gray-dark: #94a3b8;
  --border: rgba(0,0,0,0.1);
  --card-bg: rgba(0,0,0,0.03);
  --cyan: #0891b2;
  --cyan-dark: #0e7490;
  --nav-bg: rgba(240,244,248,0.92);
  --nav-bg-mobile: rgba(240,244,248,0.97);
}

/* ── LIGHT MODE: system preference (only when no manual override) ── */
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) {
    --bg: #f0f4f8;
    --bg2: #e2e8f0;
    --bg3: #cbd5e1;
    --white: #0f172a;
    --gray: #475569;
    --gray-dark: #94a3b8;
    --border: rgba(0,0,0,0.1);
    --card-bg: rgba(0,0,0,0.03);
    --cyan: #0891b2;
    --cyan-dark: #0e7490;
    --nav-bg: rgba(240,244,248,0.92);
    --nav-bg-mobile: rgba(240,244,248,0.97);
  }
}

/* ── HTML / BODY ── */
html { scroll-behavior: smooth; }

body {
  font-family: 'Inter', sans-serif;
  background: var(--bg);
  color: var(--white);
  overflow-x: hidden;
  line-height: 1.6;
}

/* ── SCROLLBAR ── */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--cyan-dark); border-radius: 3px; }

/* ── NAV ── */
nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 1000;
  padding: 0 40px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--nav-bg);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: background 0.3s, border-color 0.3s;
}

/* Index page nav starts transparent */
nav.transparent {
  background: transparent;
  border-color: transparent;
}
nav.scrolled {
  background: var(--nav-bg);
  border-color: var(--border);
}

.nav-logo {
  display: flex;
  flex-direction: column;
  line-height: 1;
  text-decoration: none;
}
.nav-logo .logo-main {
  font-size: 18px;
  font-weight: 800;
  color: var(--white);
  letter-spacing: -0.5px;
}
.nav-logo .logo-main span { color: var(--cyan); }
.nav-logo .logo-sub {
  font-size: 9px;
  font-weight: 400;
  color: var(--cyan);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-top: 1px;
}
.nav-logo .logo-sub-nav {
  font-size: 9px;
  font-weight: 400;
  color: var(--cyan);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  margin-top: 1px;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 36px;
  list-style: none;
}
.nav-links a {
  color: var(--gray);
  text-decoration: none;
  font-size: 14px;
  font-weight: 500;
  transition: color 0.2s;
}
.nav-links a:hover { color: var(--white); }
.nav-links a.active { color: var(--white); }

.nav-cta {
  background: var(--cyan);
  color: #000 !important;
  padding: 10px 22px;
  border-radius: 8px;
  font-weight: 700 !important;
  font-size: 14px !important;
  transition: background 0.2s, transform 0.2s !important;
}
.nav-cta:hover {
  background: #67e8f9 !important;
  transform: translateY(-1px);
  color: #000 !important;
}

/* Nav right-side controls */
.nav-controls {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* ── HAMBURGER ── */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  cursor: pointer;
  background: none;
  border: none;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--white);
  border-radius: 2px;
  transition: all 0.3s;
}
.hamburger.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger.open span:nth-child(2) { opacity: 0; }
.hamburger.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* ── MOBILE MENU ── */
.mobile-menu {
  display: none;
  position: fixed;
  top: 68px; left: 0; right: 0;
  background: var(--nav-bg-mobile);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  padding: 24px 24px 32px;
  z-index: 999;
  flex-direction: column;
  gap: 20px;
}
.mobile-menu.open { display: flex; }
.mobile-menu a {
  color: var(--gray);
  text-decoration: none;
  font-size: 16px;
  font-weight: 500;
  padding: 8px 0;
  border-bottom: 1px solid var(--border);
  transition: color 0.2s;
}
.mobile-menu a:last-child { border-bottom: none; }
.mobile-menu a:hover { color: var(--white); }
.mobile-menu .mob-cta {
  background: var(--cyan);
  color: #000 !important;
  padding: 14px 24px;
  border-radius: 8px;
  font-weight: 700 !important;
  text-align: center;
  border: none;
  margin-top: 4px;
}

/* ── LOGO THEME SWITCHING ── */
.logo-light { display: none; }
[data-theme="light"] .logo-dark { display: none; }
[data-theme="light"] .logo-light { display: inline; }
@media (prefers-color-scheme: light) {
  :root:not([data-theme="dark"]) .logo-dark { display: none; }
  :root:not([data-theme="dark"]) .logo-light { display: inline; }
}

/* ── THEME TOGGLE ── */
.theme-toggle {
  background: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 10px;
  cursor: pointer;
  color: var(--gray);
  font-size: 16px;
  transition: border-color 0.2s, background 0.2s;
  display: flex;
  align-items: center;
}
.theme-toggle:hover {
  border-color: var(--cyan);
  background: rgba(34,211,238,0.06);
}

/* ── LANG SWITCH ── */
.lang-switch {
  font-size: 13px;
  font-weight: 700;
  color: var(--gray);
  text-decoration: none;
  border: 1px solid var(--border);
  border-radius: 8px;
  padding: 7px 12px;
  transition: border-color 0.2s, color 0.2s;
}
.lang-switch:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

/* ── BTN-PRIMARY ── */
.btn-primary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: var(--cyan);
  color: #000;
  padding: 16px 32px;
  border-radius: 10px;
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  transition: background 0.2s, transform 0.2s, box-shadow 0.2s;
  border: none;
  cursor: pointer;
}
.btn-primary:hover {
  background: #67e8f9;
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(34,211,238,0.3);
}
.btn-primary .arrow { font-size: 18px; transition: transform 0.2s; }
.btn-primary:hover .arrow { transform: translateX(4px); }

/* ── BTN-SECONDARY ── */
.btn-secondary {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: rgba(255,255,255,0.05);
  color: var(--white);
  padding: 16px 32px;
  border-radius: 10px;
  font-weight: 600;
  font-size: 15px;
  text-decoration: none;
  transition: background 0.2s, transform 0.2s;
  border: 1px solid var(--border);
  cursor: pointer;
}
.btn-secondary:hover {
  background: rgba(255,255,255,0.09);
  transform: translateY(-2px);
}

/* ── SECTION-TAG ── */
.section-tag {
  display: inline-block;
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 2px;
  color: var(--cyan);
  margin-bottom: 16px;
}

/* ── SOCIAL LINKS ── */
.social-links { display: flex; gap: 12px; }
.social-link {
  width: 36px; height: 36px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: var(--card-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  text-decoration: none;
  font-size: 14px;
  color: var(--gray);
  transition: border-color 0.2s, color 0.2s, background 0.2s;
}
.social-link:hover {
  border-color: rgba(34,211,238,0.3);
  color: var(--cyan);
  background: rgba(34,211,238,0.05);
}

/* ── FOOTER ── */
footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 72px 40px 40px;
}
.footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1.5fr;
  gap: 60px;
  padding-bottom: 60px;
  border-bottom: 1px solid var(--border);
}
.footer-brand p {
  font-size: 14px;
  color: var(--gray);
  line-height: 1.7;
  max-width: 260px;
  margin: 16px 0 24px;
}
.footer-col h4 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  color: var(--white);
  margin-bottom: 20px;
}
.footer-col ul { list-style: none; display: flex; flex-direction: column; gap: 12px; }
.footer-col ul li { font-size: 14px; color: var(--gray); display: flex; align-items: center; gap: 8px; }
.footer-col ul li a {
  font-size: 14px;
  color: var(--gray);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-col ul li a:hover { color: var(--white); }
.contact-icon { font-size: 14px; opacity: 0.6; }
.footer-bottom {
  max-width: 1200px;
  margin: 32px auto 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 16px;
}
.footer-bottom p { font-size: 13px; color: var(--gray-dark); }
.footer-legal { display: flex; gap: 24px; }
.footer-legal a {
  font-size: 13px;
  color: var(--gray-dark);
  text-decoration: none;
  transition: color 0.2s;
}
.footer-legal a:hover { color: var(--gray); }

/* ── RESPONSIVE NAV ── */
@media (max-width: 900px) {
  nav { padding: 0 20px; }
  .nav-links { display: none; }
  .hamburger { display: flex; }
  .logo-sub-nav { display: none; }
}
@media (max-width: 768px) {
  footer { padding: 60px 20px 32px; }
  .footer-grid { grid-template-columns: 1fr 1fr; gap: 40px; }
  .footer-bottom { flex-direction: column; align-items: flex-start; }
}
@media (max-width: 540px) {
  .footer-grid { grid-template-columns: 1fr; gap: 36px; }
}