/* ============================================================
   layout.css — Mello app layout
   ============================================================
   Structure:
     1. Tokens & root vars
     2. App shell (.app, #appContent)
     3. Topbar (left / center / right zones)
     4. Brand & icon buttons
     5. Top nav (rail, items, indicator)
     6. Overflow / mobile menus
     7. Settings dropdown
     8. Dev toolbar
     9. Content area & sections
    10. Reusable tabs (mn-tabs) & pages
    11. Auth bootstrap / RBAC
    12. Responsive overrides
   ============================================================ */


/* ============================================================
   1. TOKENS & ROOT VARS
   ============================================================ */
:root {
  --mn-tabs-fixed-top: 0px;
  --mn-tabs-gap: 20px;
  --mn-fade-ms: 160ms; /* must match FADE_MS in JS */
  --mn-ease: cubic-bezier(.2, .8, .2, 1);
  --mn-indicator-radius: 999px;
  --mn-indicator-travel: rgba(20, 20, 20, 0.08);
}


/* ============================================================
   2. APP SHELL
   ============================================================ */
.app {
  position: relative;
  z-index: 1;
  height: var(--vvh);
  min-height: var(--vvh);
  box-sizing: border-box;
  overflow-y: auto;
  scrollbar-gutter: stable;
  display: flex;
  flex-direction: column;
  background: transparent;
  -webkit-overflow-scrolling: touch;
  transition: opacity 160ms ease;
  padding-bottom: 0;
}

body.gp-fs-open .app {
  overflow: hidden;
  scrollbar-gutter: auto;
}

body.gp-fs-open .topbar {
  padding-right: calc(1rem + var(--mn-scrollbar-width, 15px));
}

#appContent {
  opacity: 1;
  transition: opacity var(--mn-fade-ms) var(--mn-ease);
  will-change: opacity;
}
#appContent.is-switching {
  opacity: 0;
  pointer-events: none;
}

body.has-global-player #appContent {
  padding-bottom: calc(var(--global-player-height) + env(safe-area-inset-bottom, 0px) + 10px);
}
body.gp-fs-open.has-global-player .app {
  padding-bottom: 0;
}

.layout {
  flex: 1;
  min-height: 0;
}


/* ============================================================
   3. TOPBAR
   ============================================================
   The topbar uses a flex row. Left and right zones are absolutely
   positioned so the centre nav can be perfectly centred relative
   to the viewport on desktop. On mobile (see §12), the left zone
   becomes static so the logo flows naturally next to the nav.
*/
.topbar {
  position: sticky;
  top: 0;
  z-index: 90;
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 60px;
  padding: 0.5rem 1rem;
  border-bottom: 1px solid var(--panel-border);
  background: var(--topbar-bg);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  transition: transform 220ms var(--mn-ease), opacity 220ms var(--mn-ease);
  will-change: transform, opacity;
}
.topbar.is-hidden {
  transform: translateY(-110%);
  opacity: 0;
}

.topbar-left,
.topbar-right {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  z-index: 2;
  display: flex;
  align-items: center;
  min-width: 0;
}
.topbar-left {
  left: 1rem;
  justify-content: flex-start;
  gap: 0.5rem;
}
.topbar-right {
  right: 1rem;
  justify-content: flex-end;
  gap: 0.5rem;
}

.topbar-center {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-width: 0;
  padding-left: calc(var(--topbar-left-reserve) + var(--topbar-center-gap));
  padding-right: calc(var(--topbar-right-reserve) + var(--topbar-center-gap));
}
.topbar-center .topnav {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 100%;
  min-width: 0;
}

/* Fullscreen player tweaks */
body.gp-fs-open .topbar {
  background: color-mix(in srgb, var(--gp-fs-bg) 88%, white 12%);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid color-mix(in srgb, currentColor 18%, transparent);
}
body.gp-fs-open #topnavInner {
  background: transparent;
}


/* ============================================================
   4. BRAND & ICON BUTTONS
   ============================================================ */
.brand {
  margin: 0;
  font-family: var(--font-header);
  font-size: 1.2rem;
  letter-spacing: 0.04em;
  padding: 0.25rem 0.65rem;
  border-radius: 999px;
}
.brand:hover,
.brand:focus-visible {
  background: var(--hover-bg);
  outline: none;
}

.icon-button {
  width: clamp(30px, 3.8vw, 34px);
  height: clamp(30px, 3.8vw, 34px);
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  transition: background-color 0.2s ease, box-shadow 0.2s ease;
}
.icon-button:hover,
.icon-button:focus-visible {
  background: var(--hover-bg);
  outline: none;
  box-shadow: 0 0 0 1px var(--border-color);
}

.devtools-toggle.is-active {
  box-shadow: 0 0 0 1px var(--color-accent-soft);
  background: var(--hover-bg);
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}


/* ============================================================
   5. TOP NAV (rail, items, indicator)
   ============================================================ */
.topnav {
  display: flex;
  align-items: center;
  flex: 0 0 auto;
  min-width: 0;
}

#topnavInner,
.topnav-inner {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  flex: 1 1 auto;
  gap: var(--topnav-rail-gap);
  padding: var(--topnav-rail-pad);
  margin: 0 auto;
  min-width: 0;
  max-width: 100%;
  background: transparent;
  border: 0;
  border-radius: var(--topnav-rail-radius);
  box-shadow: none;
  overflow: hidden;
  isolation: isolate;
}

.topnav-item {
  position: relative;
  z-index: 2;
  min-width: clamp(34px, 4vw, 42px);
  padding: clamp(0.32rem, 0.9vw, 0.45rem) clamp(0.42rem, 1.2vw, 0.6rem);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: 999px;
}
.topnav-item i {
  font-size: clamp(15px, 1.8vw, 18px);
}
.topnav-item:hover,
.topnav-item:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.topnav-item.is-active {
  background: transparent;
}

/* Tooltip on icon-only items */
.topnav-item[data-label]:hover::after {
  content: attr(data-label);
  position: absolute;
  top: 120%;
  left: 50%;
  transform: translateX(-50%);
  white-space: nowrap;
  font-size: 0.75rem;
  padding: 0.25rem 0.5rem;
  border-radius: 999px;
  background: var(--panel-bg);
  border: 1px solid var(--panel-border);
  color: var(--color-text);
  pointer-events: none;
  z-index: 10;
}

/* Indicator pill that slides under the active tab */
#topnavIndicator {
  position: absolute;
  left: 0;
  top: var(--topnav-rail-pad);
  bottom: var(--topnav-rail-pad);
  height: auto;
  width: 0;
  z-index: 1;
  opacity: 0;
  transform: translateX(0);
  border-radius: 999px;
  background: var(--mn-indicator-travel);
  filter: saturate(var(--mn-indicator-sat, 1));
  transition:
    transform 260ms var(--mn-ease),
    width 260ms var(--mn-ease),
    background-color 200ms var(--mn-ease),
    opacity 160ms var(--mn-ease);
}
#topnavIndicator.is-settled {
  background: var(--mn-indicator-accent, var(--mn-indicator-travel));
}

/* Default theme: neutral while moving */
body[data-theme="default"] #topnavIndicator.is-moving,
body:not([data-theme]) #topnavIndicator.is-moving {
  background: var(--mn-indicator-travel) !important;
}
/* Non-default themes: always accent */
body[data-theme]:not([data-theme="default"]) #topnavIndicator.is-moving,
body[data-theme]:not([data-theme="default"]) #topnavIndicator.is-settled {
  background: var(--mn-indicator-accent) !important;
}

/* Per-section accent tokens (default theme only) */
body[data-theme="default"] .topnav-item[data-section="home"].is-active ~ #topnavIndicator,
body:not([data-theme]) .topnav-item[data-section="home"].is-active ~ #topnavIndicator {
  --mn-indicator-accent: var(--nav-accent-home);
}
body[data-theme="default"] .topnav-item[data-section="learning"].is-active ~ #topnavIndicator,
body:not([data-theme]) .topnav-item[data-section="learning"].is-active ~ #topnavIndicator {
  --mn-indicator-accent: var(--nav-accent-search);
}
body[data-theme="default"] .topnav-item[data-section="news"].is-active ~ #topnavIndicator,
body:not([data-theme]) .topnav-item[data-section="news"].is-active ~ #topnavIndicator {
  --mn-indicator-accent: var(--nav-accent-news);
}


/* ============================================================
   6. OVERFLOW / MOBILE MENUS
   ============================================================ */
.nav-overflow {
  position: relative;
}
#navMobileToggle {
  display: none;
}

#navOverflowToggle {
  display: inline-flex;
  visibility: hidden;
  pointer-events: none;
}

#navOverflowToggle.is-active {
  visibility: visible;
  pointer-events: auto;
}

.nav-menu {
  position: absolute;
  right: 0;
  top: calc(100% + 0.5rem);
  min-width: 220px;
  padding: 0.4rem;
  border-radius: var(--radius-panel);
  border: 1px solid var(--panel-border);
  background: var(--topbar-bg);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  z-index: 1000;
}

.nav-menu-item {
  display: block;
  width: 100%;
  padding: 0.5rem 0.6rem;
  border: 0;
  border-radius: 10px;
  background: transparent;
  color: inherit;
  text-align: left;
  font-family: var(--font-header);
  font-weight: 700;
  cursor: pointer;
}
.nav-menu-item:hover,
.nav-menu-item:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.nav-menu-item.is-active {
  background: rgba(255, 255, 255, 0.12);
}

.hidden {
  display: none !important;
}
.settings-dropdown.hidden,
.nav-menu.hidden {
  display: none !important;
}


/* ============================================================
   7. SETTINGS DROPDOWN
   ============================================================ */
.settings-menu {
  position: relative;
}
.settings-dropdown {
  position: absolute;
  right: 0;
  top: 100%;
  min-width: 220px;
  padding: 0.5rem 0.5rem 0.4rem;
  border-radius: var(--radius-panel);
  border: 1px solid var(--panel-border);
  background: var(--topbar-bg);
  box-shadow: 0 18px 32px rgba(0, 0, 0, 0.25);
  backdrop-filter: none;
  -webkit-backdrop-filter: none;
  z-index: 20;
}

.settings-section {
  padding: 0.25rem 0;
}
.settings-section + .settings-section {
  border-top: 1px solid var(--border-color);
  margin-top: 0.4rem;
  padding-top: 0.4rem;
}
.settings-section-title {
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.09em;
  opacity: 0.75;
  margin: 0 0 0.15rem;
  padding: 0 0.25rem;
}

.settings-item {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.35rem 0.4rem;
  border-radius: 0.5rem;
  background: transparent;
  text-align: left;
  font-family: var(--font-header);
  font-size: 0.95rem;
  font-weight: 700;
}
.settings-item:hover,
.settings-item:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.settings-item.is-danger {
  color: color-mix(in srgb, var(--color-accent-soft) 55%, currentColor);
}
.settings-item.is-danger:hover,
.settings-item.is-danger:focus-visible {
  background: color-mix(in srgb, var(--color-accent-soft) 22%, var(--hover-bg));
}

.theme-option {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0.35rem 0.4rem;
  border-radius: 0.5rem;
  text-align: left;
  font-size: 0.95rem;
}
.theme-option:hover,
.theme-option:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.theme-option.is-active {
  background: var(--hover-bg);
  font-weight: 500;
}

.theme-badge {
  font-size: 0.7rem;
  padding: 0.05rem 0.4rem;
  border-radius: 999px;
  border: 1px solid var(--border-color);
  opacity: 0.9;
}
.theme-badge-soft {
  opacity: 0.7;
}


/* ============================================================
   8. DEV TOOLBAR
   ============================================================ */
.dev-toolbar {
  border-bottom: 1px dashed var(--border-color);
  padding: 0.45rem 1.1rem;
  background: color-mix(in srgb, var(--color-bg) 70%, var(--panel-bg) 30%);
  backdrop-filter: blur(10px);
}
.dev-toolbar-inner {
  max-width: 900px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.dev-toolbar-label {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  opacity: 0.7;
  white-space: nowrap;
}
.dev-toolbar-time {
  font-family: var(--font-header);
  font-size: 0.9rem;
  opacity: 0.85;
  white-space: nowrap;
}
.dev-toolbar input[type="range"] {
  flex: 1;
  accent-color: var(--color-accent-soft);
}


/* ============================================================
   9. CONTENT AREA & SECTIONS
   ============================================================ */
.content {
  padding: 1.1rem;
  min-width: 0;
  scrollbar-gutter: stable both-edges;
}

.section {
  display: none;
}
.section.active {
  display: block;
}

/* Sidebar nav items (legacy/secondary) */
.sidebar .nav-label {
  font-family: var(--font-header);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  font-size: 0.72rem;
  opacity: 0.9;
}
.nav-item {
  width: 100%;
  display: flex;
  align-items: center;
  gap: 0.6rem;
  padding: 0.45rem 0.7rem;
  border-radius: var(--radius-panel);
  text-align: left;
  font-size: 0.98rem;
}
.nav-item:hover,
.nav-item:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.nav-item.active {
  background: var(--hover-bg);
}
.nav-icon {
  width: 1.5rem;
  display: inline-flex;
  align-items: center;
  justify-content: center;
}
.nav-icon i {
  font-size: 1rem;
}


/* ============================================================
   10. REUSABLE TABS (mn-tabs) & PAGES
   ============================================================ */
.mn-tabs {
  display: flex;
  flex-wrap: wrap;
  width: fit-content;
  max-width: calc(100vw - 2.2rem);
  margin: 0 auto;
  gap: 0.35rem;
  padding: 0.25rem;
  border: 1px solid var(--panel-border);
  background: color-mix(in srgb, var(--panel-bg) 70%, transparent);
  border-radius: var(--radius-panel);
  justify-content: center;
}

.mn-tabs-spacer {
  height: 0px;
}

.mn-tabs.is-fixed {
  position: fixed;
  top: calc(var(--mn-tabs-fixed-top) + var(--mn-tabs-gap));
  left: 50%;
  transform: translateX(-50%);
  z-index: 60;
  max-width: calc(100vw - 2.2rem);
  flex-wrap: wrap;
  box-shadow: 0 10px 22px rgba(0, 0, 0, 0.18);
  transition: transform 220ms var(--mn-ease), opacity 220ms var(--mn-ease);
  will-change: transform, opacity;
}
.mn-tabs.is-fixed.is-hidden {
  transform: translateY(-110%);
  opacity: 0;
}

.mn-tab {
  padding: 0.45rem 0.75rem;
  border-radius: calc(var(--radius-panel) - 2px);
  font-family: var(--font-header);
  font-weight: 800;
  letter-spacing: 0.02em;
  opacity: 0.9;
}
.mn-tab:hover,
.mn-tab:focus-visible {
  background: var(--hover-bg);
  outline: none;
}
.mn-tab.is-active {
  background: color-mix(in srgb, var(--color-accent-soft) 35%, transparent);
  opacity: 1;
}
.mn-tabpanel.hidden {
  display: none !important;
}

.mn-page {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
}
.mn-page-wide {
  width: 100%;
  max-width: 1300px;
  margin: 0 auto;
}


/* ============================================================
   11. AUTH BOOTSTRAP / RBAC
   ============================================================ */
.role-hidden,
.topnav-item.role-hidden {
  display: none !important;
}

body.auth-pending .topnav-item {
  visibility: hidden;
}
body.auth-pending .topnav-item[data-section="home"] {
  visibility: visible;
}
body.auth-pending #navOverflowToggle,
body.auth-pending #topnavIndicator {
  display: none !important;
}
body.auth-pending .topnav {
  pointer-events: none;
  opacity: 0.95;
}


/* ============================================================
   12. RESPONSIVE OVERRIDES
   ============================================================ */

/* ---- ≤900px: mobile topbar layout ----
   Logo flows naturally beside the nav (no absolute positioning
   on the left zone). Right zone stays pinned to the edge. */
@media (max-width: 900px) {
  /* Topbar becomes a normal left-aligned flex row */
  .topbar {
    align-items: center;
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }

  .topbar-left {
    position: static;
    transform: none;
    top: auto;
    left: auto;
    bottom: auto;

    display: flex;
    align-items: center;
    justify-content: center;

    flex: 0 0 auto;
    width: auto;
    min-width: 0;
    max-width: max-content;
    height: auto;
    margin: 0;
    padding: 0;
  }

  .brand {
    display: flex;
    align-items: center;
    justify-content: center;
    height: 44px;
    min-width: 44px;
    padding: 0;
    margin: 0;
  }

  .brand-logo {
    display: block;
    height: 27px;   /* explicit instead of 75% */
    width: auto;
  }

  /* Right zone: stays pinned to the right edge */
  .topbar-right {
    right: 1.5rem;
    gap: 0.35rem;
  }

  /* Center zone: takes remaining space, no left padding (logo is in flow now),
     right padding only to clear the absolutely-positioned right zone */
  .topbar-center {
    flex: 1 1 0;
    width: auto;
    min-width: 0;
    padding-left: 0;
    padding-right: calc(var(--topbar-right-reserve) + 2px);
  }
  .topbar-center .topnav {
    justify-content: flex-start;
    width: 100%;
  }

  #topnavInner {
    margin: 0;
    gap: 1px;
    max-width: 100%;
    flex: 1 1 auto;
    justify-content: space-around;   /* ← spread icons evenly */
  }

  .topnav-item {
    min-width: 28px;
    padding: 0.3rem 0.28rem;
  }

  /* Hamburger stays hidden — overflow menu handles overflow */
  #navMobileToggle,
  .nav-hamburger,
  .nav-hamburger-left {
    display: none !important;
  }
  .nav-overflow {
    display: inline-flex;
  }
}

/* ---- ≤760px: drop the redundant Home tab (logo serves as Home) ---- */
@media (max-width: 760px) {
  .topnav-item[data-section="home"] {
    display: none !important;
  }
}

/* ---- ≤740px: news section goes full-bleed ---- */
@media (max-width: 740px) {
  body[data-section="news"] .content {
    padding-left: 0 !important;
    padding-right: 0 !important;
    scrollbar-gutter: auto;
  }
}

/* ---- ≤720px: layout collapses, hide dev label ---- */
@media (max-width: 720px) {
  .layout {
    display: flex;
    flex-direction: column;
  }
  .content {
    margin-left: 0;
  }
  .dev-toolbar-inner {
    gap: 0.5rem;
  }
  .dev-toolbar-label {
    display: none;
  }
}

/* ---- ≤640px: tightest spacing ---- */
@media (max-width: 640px) {
  .topbar-right {
    right: 1.5rem;
  }
  .topbar-center {
    padding-right: calc(var(--topbar-right-reserve) + 4px);
  }
  .topnav-item {
    min-width: 30px;
    padding: 0.3rem 0.3rem;
  }
}