/* ─────────── NAVBAR ─────────── */

.bt-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 999;
  background: rgba(5, 11, 26, 0.45);
  backdrop-filter: blur(18px);
  -webkit-backdrop-filter: blur(18px);
  border-bottom: 1px solid rgba(137, 166, 199, 0.1);
  transition: background-color 0.25s, border-color 0.25s, box-shadow 0.25s;
}

html[data-theme="light"] .bt-nav {
  background: rgba(248, 250, 252, 0.58);
  border-bottom-color: rgba(51, 65, 85, 0.12);
}

.bt-nav.scrolled {
  background: rgba(5, 11, 26, 0.72);
  border-bottom-color: rgba(137, 166, 199, 0.22);
  box-shadow: 0 8px 24px -12px rgba(0, 0, 0, 0.6);
}

html[data-theme="light"] .bt-nav.scrolled {
  background: rgba(248, 250, 252, 0.78);
  border-bottom-color: rgba(51, 65, 85, 0.16);
}

.bt-nav-container {
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-5);
}

.bt-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  background: transparent;
  border: 0;
  cursor: pointer;
  padding: 0;
  font-family: var(--font-display);
  text-decoration: none;
}

.bt-brand-name {
  color: var(--text);
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.01em;
}

html[data-theme="light"] .bt-brand-name {
  color: var(--text);
}

.bt-brand-mark {
  width: 32px;
  height: 32px;
  border-radius: 9px;
  background: linear-gradient(140deg, var(--blue), var(--blue-deep));
  display: grid;
  place-items: center;
  box-shadow: 0 4px 12px rgba(61, 88, 119, 0.4);
  flex-shrink: 0;
}

.bt-nav-desktop {
  display: flex;
  align-items: center;
  gap: 34px;
  /* margin-left: auto; */
}

.bt-nav-link {
  color: var(--text-2);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 400;
  text-decoration: none;
  transition: color 0.15s;
  white-space: nowrap;
}

.bt-nav-link:hover {
  color: var(--text);
}

.bt-nav-actions {
  display: flex;
  align-items: center;
  gap: 18px;
}

.bt-login {
  margin-left: 6px;
}

.bt-signup {
  min-width: max-content;
}

/* ─────────── THEME TOGGLE ─────────── */

.theme-toggle {
  width: 56px;
  height: 28px;
  padding: 3px;
  border-radius: var(--radius-full);
  background: rgba(148, 163, 184, 0.14);
  border: 1px solid rgba(148, 163, 184, 0.2);
  cursor: pointer;
  position: relative;
  display: inline-flex;
  align-items: center;
  transition: background-color 0.2s, border-color 0.2s;
}

.theme-toggle:hover {
  background: rgba(148, 163, 184, 0.22);
}

.theme-toggle .thumb {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: linear-gradient(140deg, var(--blue), var(--blue-deep));
  box-shadow: 0 2px 6px rgba(61, 88, 119, 0.5);
  transition: transform 0.25s cubic-bezier(0.4, 0, 0.2, 1), background 0.25s, box-shadow 0.25s;
  display: grid;
  place-items: center;
  color: #fff;
}

.theme-toggle .thumb svg {
  width: 12px;
  height: 12px;
}

.theme-toggle .sun,
.theme-toggle .moon {
  display: none;
}

html[data-theme="dark"] .theme-toggle .moon {
  display: block;
}

html[data-theme="light"] .theme-toggle .thumb {
  transform: translateX(28px);
  background: linear-gradient(140deg, #fbbf24, #f59e0b);
  box-shadow: 0 2px 6px rgba(251, 191, 36, 0.5);
}

html[data-theme="light"] .theme-toggle .sun {
  display: block;
}

/* ─────────── LANGUAGE ─────────── */

.bt-lang {
  position: relative;
}

.bt-lang-button {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: transparent;
  border: 0;
  color: var(--text-2);
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  padding: 0;
}

.bt-lang-button:hover {
  color: var(--text);
}

.lang-arrow {
  transition: transform 0.15s ease;
}

.lang-arrow.rotate {
  transform: rotate(180deg);
}

.lang-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 10px);
  z-index: 60;
  min-width: 160px;
  padding: 6px;
  border-radius: var(--radius-md);
  background: rgba(11, 18, 38, 0.96);
  border: 1px solid rgba(137, 166, 199, 0.22);
  box-shadow: var(--shadow-md);
  backdrop-filter: blur(14px);
}

html[data-theme="light"] .lang-menu {
  background: rgba(255, 255, 255, 0.96);
  border-color: rgba(51, 65, 85, 0.14);
}

.lang-menu button {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 10px;
  border: 0;
  border-radius: 6px;
  background: transparent;
  color: var(--text-2);
  font-size: 13px;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
}

.lang-menu button:hover,
.lang-menu button.active {
  background: rgba(76, 106, 146, 0.14);
  color: var(--steel-soft);
}

/* ─────────── MOBILE ─────────── */

.bt-mobile-toggle {
  display: none;
  background: transparent;
  border: 0;
  color: var(--text);
  cursor: pointer;
  padding: 0;
}

.mobile-menu-panel {
  display: none;
}