/* ── Navbar ───────────────────────────────────────── */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(10,10,10,0.92);
  border-bottom: 1px solid var(--color-border);
}

.navbar-inner {
  display: flex;
  align-items: center;
  gap: 20px;
  padding: 12px 28px;
  height: var(--nav-height);
}

.navbar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-shrink: 0;
}

.navbar-logo {
  width: 34px; height: 34px;
  background: var(--color-primary);
  clip-path: polygon(25% 0, 100% 0, 100% 75%, 75% 100%, 0 100%, 0 25%);
  display: grid;
  place-items: center;
}

.navbar-brand-text {
  display: flex;
  flex-direction: column;
  gap: 0;
}

.navbar-spacer { flex: 1; }

/* Desktop tabs */
.nav-tabs-desktop {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.nav-tab {
  border: none;
  background: transparent;
  cursor: pointer;
  border-bottom: 2px solid transparent;
  color: var(--color-text-muted);
  padding: 8px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.1em;
  transition: color 0.15s, border-color 0.15s;
  white-space: nowrap;
}
.nav-tab:hover { color: var(--color-text); }
.nav-tab.active {
  color: var(--color-primary);
  border-bottom-color: var(--color-primary);
}

.nav-tab-code {
  opacity: 0.5;
  font-size: 9px;
  margin-right: 6px;
}

/* Decorative stripe */
.navbar-stripe {
  height: 4px;
  background: linear-gradient(
    90deg,
    var(--color-primary) 0%, var(--color-primary) 18%,
    transparent 18%, transparent 22%,
    var(--color-text-muted) 22%, var(--color-text-muted) 24%,
    transparent 24%
  );
}

/* Burger */
.nav-burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
  width: 36px; height: 36px;
  background: transparent;
  border: 1px solid var(--color-border-2);
  cursor: pointer;
  padding: 8px;
}
.nav-burger span {
  display: block;
  width: 100%; height: 2px;
  background: var(--color-text);
}

/* Mobile menu */
.nav-mobile-menu {
  border-top: 1px solid var(--color-border);
  padding: 8px 12px;
  background: var(--color-bg-2);
}
.nav-tab-mobile {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px 14px;
  background: transparent;
  border: 1px solid transparent;
  color: var(--color-text-muted);
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  margin-bottom: 4px;
  transition: all 0.15s;
}
.nav-tab-mobile:hover,
.nav-tab-mobile.active {
  background: var(--color-primary-dim);
  border-color: var(--color-primary);
  color: var(--color-primary);
}

/* ── Main content ─────────────────────────────────── */
.main-content {
  margin-top: var(--nav-height);
  min-height: calc(100vh - var(--nav-height));
}

.view {
  width: 100%;
  min-height: calc(100vh - var(--nav-height));
}

/* ── Page container ───────────────────────────────── */
.page-container {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 24px;
}

.page-header { margin-bottom: 32px; }
.page-header h1 { margin-bottom: 8px; }
.page-header p   { color: var(--color-text-muted); }

/* ── Study / Practice grids ───────────────────────── */
.materias-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}

.subtemas-list { display: flex; flex-direction: column; gap: 8px; }

.subtema-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 18px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  width: 100%;
}
.subtema-item:hover { border-color: var(--color-primary); background: var(--color-surface-2); }
.subtema-item-name { font-size: 0.95rem; font-weight: 500; }
.subtema-item-meta { display: flex; align-items: center; gap: 8px; }

/* ── Session header ───────────────────────────────── */
.session-header {
  position: sticky;
  top: var(--nav-height);
  z-index: 50;
  background: #0d0d0d;
  border-bottom: 1px solid var(--color-border);
  padding: 12px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.session-header-info { display: flex; flex-direction: column; gap: 4px; flex: 1; }
.session-header-title { font-size: 0.85rem; font-weight: 600; color: var(--color-text-muted); }
.session-header-progress { width: 100%; max-width: 300px; }

.session-body {
  max-width: 800px;
  margin: 0 auto;
  padding: 32px 24px;
}

.session-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 24px 0 8px;
  gap: 16px;
}

/* Divider */
.divider { height: 1px; background: var(--color-border); margin: 24px 0; }

/* ── UserMenu ──────────────────────────────────────── */
.user-menu-wrap {
  position: relative;
  display: flex;
  align-items: center;
  gap: 4px;
  flex-shrink: 0;
}

.user-dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  min-width: 200px;
  background: var(--surface);
  border: 1px solid var(--line-2);
  z-index: 200;
  box-shadow: 0 8px 32px rgba(0,0,0,0.8);
  animation: scaleIn 0.15s ease;
}

.user-menu-btn:hover { border-color: var(--line-2) !important; }

/* ── Responsive ───────────────────────────────────── */
@media (max-width: 820px) {
  .nav-tabs-desktop { display: none !important; }
  .nav-burger       { display: flex !important; }
}

@media (max-width: 768px) {
  .navbar-inner { padding: 10px 16px; gap: 12px; }
  .page-container { padding: 20px 16px; }
  .materias-grid  { grid-template-columns: 1fr; }
  .session-header { padding: 10px 16px; flex-wrap: wrap; gap: 8px; }
  .session-body   { padding: 20px 16px; }
}

@media (max-width: 520px) {
  .navbar-brand-text { display: none; }
  .navbar-inner > .navbar-brand { gap: 0; }
}