/* ============================================================
   base.css — Reset, root layout shell, typography, utilities
   Owns: *, html/body, #app, #app-header, #app-content,
   #bottom-nav (container), .screen, base type, a11y, keyframes.
   Component & screen visuals live in components.css / screens.css
   ============================================================ */

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

html {
  height: 100%;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  font-size: 16px;
}

body {
  height: 100%;
  overflow: hidden;
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  font-weight: var(--fw-normal);
  line-height: var(--lh-base);
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  transition: background var(--dur-base) var(--ease-out), color var(--dur-base) var(--ease-out);
}

img, svg { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }
ul, ol { list-style: none; }
a { color: inherit; text-decoration: none; }

/* Material Symbols defaults */
.material-symbols-rounded {
  font-variation-settings: 'FILL' 0, 'wght' 400, 'GRAD' 0, 'opsz' 24;
  font-size: 1.25rem;
  line-height: 1;
  user-select: none;
  flex-shrink: 0;
}

/* ── App shell ────────────────────────────────────────────── */
#app {
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100%;
  height: 100dvh;
  overflow: hidden;
  position: relative;
}

/* Top header */
#app-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  height: calc(var(--header-h) + var(--safe-top));
  padding-top: var(--safe-top);
  padding-left: max(var(--safe-left), var(--sp-1));
  padding-right: max(var(--safe-right), var(--sp-1));
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  background: var(--glass);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-bottom: 1px solid var(--border);
  z-index: var(--z-header);
}

/* Scrollable content region */
#app-content {
  flex: 1 1 auto;
  overflow-y: auto;
  overflow-x: hidden;
  -webkit-overflow-scrolling: touch;
  margin-top: calc(var(--header-h) + var(--safe-top));
  padding-bottom: calc(var(--nav-h) + var(--safe-bottom));
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
}

/* Bottom navigation container */
#bottom-nav {
  position: fixed;
  bottom: 0; left: 0; right: 0;
  height: calc(var(--nav-h) + var(--safe-bottom));
  padding-bottom: var(--safe-bottom);
  padding-left: var(--safe-left);
  padding-right: var(--safe-right);
  display: flex;
  align-items: stretch;
  background: var(--glass);
  backdrop-filter: blur(16px) saturate(180%);
  -webkit-backdrop-filter: blur(16px) saturate(180%);
  border-top: 1px solid var(--border);
  z-index: var(--z-nav);
}

/* Screen wrapper (router injects .screen) */
.screen {
  display: block;
  width: 100%;
  min-height: 100%;
  max-width: var(--content-max);
  margin: 0 auto;
}

/* ── Base typography helpers ──────────────────────────────── */
h1, h2, h3, h4 { line-height: var(--lh-snug); font-weight: var(--fw-bold); color: var(--text); }
:lang(ko) { word-break: keep-all; }

/* ── Accessibility ────────────────────────────────────────── */
:focus-visible {
  outline: 2px solid var(--ring);
  outline-offset: 2px;
  border-radius: var(--r-xs);
}
.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;
}

/* ── Scrollbars ───────────────────────────────────────────── */
#app-content::-webkit-scrollbar { width: 8px; }
#app-content::-webkit-scrollbar-thumb { background: var(--border-strong); border-radius: var(--r-full); }
#app-content::-webkit-scrollbar-track { background: transparent; }

/* ── Utilities ────────────────────────────────────────────── */
.hidden { display: none !important; }
.no-scroll { overflow: hidden !important; }
.text-center { text-align: center; }
.full-w { width: 100%; }

/* ── Loading overlay ──────────────────────────────────────── */
#loading-overlay {
  position: fixed; inset: 0;
  background: var(--bg);
  display: flex; align-items: center; justify-content: center;
  z-index: 9999;
  transition: opacity var(--dur-base) var(--ease-out);
}
#loading-overlay.hide { opacity: 0; pointer-events: none; }
.loading-spinner {
  width: 44px; height: 44px;
  border: 3px solid var(--border);
  border-top-color: var(--primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ── Keyframes (shared) ───────────────────────────────────── */
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes fadeIn { from { opacity: 0; } to { opacity: 1; } }
@keyframes fadeInUp { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: none; } }
@keyframes slideDown { from { opacity: 0; transform: translateY(-8px); } to { opacity: 1; transform: none; } }
@keyframes popIn {
  0% { opacity: 0; transform: scale(0.85); }
  60% { opacity: 1; transform: scale(1.04); }
  100% { transform: scale(1); }
}
@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20%, 60% { transform: translateX(-5px); }
  40%, 80% { transform: translateX(5px); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.6; }
}

.animate-fade-in { animation: fadeIn var(--dur-base) var(--ease-out) both; }
.animate-fade-up { animation: fadeInUp var(--dur-base) var(--ease-out) both; }
.animate-pop-in  { animation: popIn var(--dur-slow) var(--ease-spring) both; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* ── Desktop: sidebar nav ─────────────────────────────────── */
@media (min-width: 1024px) {
  #bottom-nav {
    top: 0; bottom: 0; right: auto;
    width: var(--sidebar-w);
    height: auto;
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: var(--sp-1);
    padding-top: calc(var(--header-h) + var(--safe-top) + var(--sp-4));
    padding-left: var(--sp-3);
    padding-right: var(--sp-3);
    border-top: none;
    border-right: 1px solid var(--border);
  }
  #app-content { margin-left: var(--sidebar-w); }
}