*, *::before, *::after { box-sizing: border-box; }
html, body { height: 100%; margin: 0; }
body { background: var(--bg); color: var(--text); font-family: var(--font); font-size: 0.9375rem; line-height: 1.5; overflow: hidden; -webkit-font-smoothing: antialiased; -webkit-tap-highlight-color: transparent; overscroll-behavior: none; }
button, input, select, textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: 0; padding: 0; }
button:disabled { cursor: not-allowed; opacity: 0.45; }
h1, h2, h3, h4, p { margin: 0; }
ul { margin: 0; padding: 0; list-style: none; }
.sr { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
.mono, .ltr { font-family: var(--font-mono); }
.ltr { direction: ltr; unicode-bidi: isolate; display: inline-block; }
.ic { width: 1.25rem; height: 1.25rem; display: block; flex: none; }
[hidden] { display: none !important; }

:focus-visible { outline: 2px solid var(--accent-2); outline-offset: 3px; border-radius: 4px; }
:root[data-contrast='high'] :focus-visible { outline-width: 3px; outline-color: #FFD84D; }
:root[data-theme='light'] :focus-visible { outline-color: #8A5B00; }
::selection { background: var(--accent); color: var(--on-accent); }

.skip { position: fixed; inset-inline-start: 12px; top: -60px; z-index: 200; background: var(--hi-bg); color: var(--hi-text); padding: 10px 16px; border-radius: 8px; font-weight: 700; transition: top 0.2s; }
.skip:focus { top: calc(10px + var(--safe-t)); }

/* progressive disclosure: levels reveal controls, they never lock features */
:root[data-level='beginner'] .lvl-int, :root[data-level='beginner'] .lvl-adv { display: none !important; }
:root[data-level='intermediate'] .lvl-adv { display: none !important; }
:root[data-level='advanced'] .only-beginner { display: none !important; }
:root[data-level='intermediate'] .only-beginner { display: none !important; }

:root[data-motion='reduced'] *, :root[data-motion='reduced'] *::before, :root[data-motion='reduced'] *::after { animation-duration: 0.001ms !important; animation-iteration-count: 1 !important; transition-duration: 0.001ms !important; scroll-behavior: auto !important; }

/* shared controls */
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; min-height: 44px; padding: 0 1.1rem; border: 1px solid var(--line); border-radius: 999px; background: var(--glass); backdrop-filter: blur(var(--blur)); -webkit-backdrop-filter: blur(var(--blur)); color: var(--text); font-weight: 600; letter-spacing: 0.04em; font-size: 0.875rem; transition: background 0.2s, color 0.2s, border-color 0.2s, transform 0.2s; }
.btn:hover { background: var(--glass-hi); }
.btn:active { transform: scale(0.98); }
.btn.primary { background: var(--hi-bg); color: var(--hi-text); border-color: transparent; }
.btn.primary:hover { filter: brightness(0.92); }
.btn.accent { background: var(--accent); color: var(--on-accent); border-color: transparent; }
.btn.ghost { background: transparent; }
.btn.small { min-height: 36px; padding: 0 0.85rem; font-size: 0.8125rem; }
.btn.lg { min-height: 54px; padding: 0 1.6rem; font-size: 1rem; }
.btn[aria-pressed='true'], .btn.on { background: var(--hi-bg); color: var(--hi-text); }
.eyebrow { font-size: 0.6875rem; letter-spacing: 0.22em; text-transform: uppercase; color: var(--muted); font-weight: 600; }
:root[lang='ar'] .eyebrow, :root[lang='ar'] .stat .k, :root[lang='ar'] .lbl, :root[lang='ar'] .ctx button, :root[lang='ar'] .mm-btn { letter-spacing: 0; text-transform: none; }
.chip { display: inline-flex; align-items: center; gap: 0.35rem; padding: 2px 10px; border-radius: 999px; border: 1px solid var(--line-soft); font-size: 0.75rem; color: var(--muted); }
.chip.demo { color: var(--accent-2); border-color: color-mix(in srgb, var(--accent-2) 55%, transparent); }
.chip.real { color: var(--ok); border-color: color-mix(in srgb, var(--ok) 55%, transparent); }
.chip.warn { color: var(--warn); border-color: color-mix(in srgb, var(--warn) 55%, transparent); }
.chip.bad { color: var(--danger); border-color: color-mix(in srgb, var(--danger) 55%, transparent); }

.toasts { position: fixed; inset-inline: 0; bottom: calc(150px + var(--safe-b)); display: flex; flex-direction: column; align-items: center; gap: 8px; z-index: 300; pointer-events: none; }
.toast { background: var(--glass-strong); border: 1px solid var(--line); padding: 10px 16px; border-radius: 12px; box-shadow: var(--shadow); max-width: min(92vw, 460px); animation: toast-in 0.3s var(--ease); font-size: 0.875rem; backdrop-filter: blur(var(--blur)); }
.toast.out { opacity: 0; transition: opacity 0.3s; }
@keyframes toast-in { from { opacity: 0; transform: translateY(10px); } }

.boot { position: fixed; inset: 0; z-index: 500; display: grid; place-content: center; justify-items: center; gap: 14px; background: var(--bg); color: var(--muted); letter-spacing: 0.2em; text-transform: uppercase; font-size: 0.75rem; transition: opacity 0.6s; }
.boot.gone { opacity: 0; pointer-events: none; }
.boot-dot { width: 12px; height: 12px; border-radius: 50%; background: var(--accent-2); box-shadow: 0 0 0 0 var(--accent-2); animation: pulse 1.6s infinite; }
@keyframes pulse { 70% { box-shadow: 0 0 0 20px transparent; } 100% { box-shadow: 0 0 0 0 transparent; } }

.spinner { width: 22px; height: 22px; border-radius: 50%; border: 2px solid var(--line-soft); border-top-color: var(--accent); animation: spin 0.9s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }
.skeleton { background: linear-gradient(90deg, var(--glass-hi), transparent, var(--glass-hi)); background-size: 200% 100%; animation: shimmer 1.4s infinite; border-radius: 8px; }
@keyframes shimmer { to { background-position: -200% 0; } }

.state { display: grid; gap: 8px; justify-items: start; padding: 14px; border: 1px dashed var(--line); border-radius: 12px; color: var(--muted); font-size: 0.875rem; }
.state strong { color: var(--text); font-weight: 700; }
.state.err { border-color: color-mix(in srgb, var(--danger) 60%, transparent); }
.state .ic { color: var(--accent-2); }