/* =========================================================
   QBox Infrastructure – Loading System v5.0
   Deterministic • Token-driven • Motion-safe
========================================================= */


/* =========================================================
   BUTTON LOADING STATE
========================================================= */

.btn.is-loading {
    position: relative;
    pointer-events: none;
    opacity: 0.9;
}

    /* Hide content but preserve layout */
    .btn.is-loading > span,
    .btn.is-loading > .btn-text {
        visibility: hidden;
    }

    /* Spinner centered absolutely */
    .btn.is-loading::after {
        content: "";
        position: absolute;
        width: 18px;
        height: 18px;
        top: 50%;
        left: 50%;
        transform: translate(-50%, -50%);
        border-radius: 50%;
        border: 2px solid rgba(255, 255, 255, 0.4);
        border-top-color: #ffffff;
        animation: qbox-spin 0.7s linear infinite;
    }

/* Secondary / Outline variants */
.btn-secondary.is-loading::after,
.btn-outline.is-loading::after {
    border: 2px solid var(--border-strong);
    border-top-color: var(--brand-primary);
}


/* =========================================================
   INLINE SPINNER
========================================================= */

.spinner {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    border: 2px solid var(--border-default);
    border-top-color: var(--brand-primary);
    animation: qbox-spin 0.7s linear infinite;
    will-change: transform;
}


/* =========================================================
   FULL PAGE LOADER
========================================================= */

.page-loader {
    position: fixed;
    inset: 0;
    z-index: var(--z-overlay, 9999);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.35);
    backdrop-filter: blur(6px);
    opacity: 0;
    pointer-events: none;
    transition: opacity 180ms ease;
    /* Prevent accidental focus */
    isolation: isolate;
}

    .page-loader.active {
        opacity: 1;
        pointer-events: all;
    }

/* Prevent page scroll when active */
body.qbox-loading {
    overflow: hidden;
}


/* =========================================================
   LOADER CARD
========================================================= */

.page-loader-inner {
    background: var(--surface-0);
    padding: var(--space-6);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-4);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-3);
    min-width: 160px;
    text-align: center;
    opacity: 0;
    transform: translateY(6px);
    transition: opacity 150ms ease, transform 150ms ease;
}

.page-loader.active .page-loader-inner {
    opacity: 1;
    transform: translateY(0);
}

.loader-message {
    font-size: var(--text-sm);
    color: var(--text-secondary);
}


/* =========================================================
   ANIMATION
========================================================= */

@keyframes qbox-spin {
    to {
        transform: rotate(360deg);
    }
}


/* =========================================================
   MOTION SAFETY (Accessibility)
========================================================= */

@media (prefers-reduced-motion: reduce) {

    .spinner,
    .btn.is-loading::after {
        animation: none;
    }

    .page-loader {
        transition: none;
    }
}