/* ─────────────────────────────────────────────────────────────────────
   Science4Data shared loader overlay.
   Reusable on any page — pair with /scripts/loader.js.

   Usage (HTML):
     <link rel="stylesheet" href="/styles/loader.css">
     <script src="/scripts/loader.js" defer></script>
     <a href="/somewhere" data-s4d-loader="Loading case study…">Go</a>

   Usage (JS):
     S4DLoader.show('Generating report…');
     S4DLoader.hide();
   ───────────────────────────────────────────────────────────────────── */

.s4d-loader-overlay {
    position: fixed;
    inset: 0;
    background: rgba(20, 8, 40, 0.55);
    backdrop-filter: blur(6px);
    -webkit-backdrop-filter: blur(6px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 99999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
}

.s4d-loader-overlay.s4d-loader-visible {
    opacity: 1;
    pointer-events: auto;
}

.s4d-loader-card {
    background: #ffffff;
    border-radius: 18px;
    padding: 2rem 2.5rem 1.75rem;
    box-shadow:
        0 20px 60px rgba(75, 0, 110, 0.28),
        0 4px 12px rgba(75, 0, 110, 0.12);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    min-width: 260px;
    max-width: 360px;
    transform: translateY(10px) scale(0.96);
    transition: transform 0.28s cubic-bezier(0.16, 1, 0.3, 1);
}

.s4d-loader-overlay.s4d-loader-visible .s4d-loader-card {
    transform: translateY(0) scale(1);
}

.s4d-loader-spinner {
    width: 56px;
    height: 56px;
    position: relative;
}

.s4d-loader-spinner::before,
.s4d-loader-spinner::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: 50%;
    border: 4px solid transparent;
    border-top-color: #4B006E;
    border-right-color: #00acb3;
    animation: s4dLoaderSpin 0.9s linear infinite;
}

.s4d-loader-spinner::after {
    inset: 9px;
    border-top-color: #00acb3;
    border-right-color: #4B006E;
    animation-direction: reverse;
    animation-duration: 0.7s;
}

@keyframes s4dLoaderSpin {
    to { transform: rotate(360deg); }
}

.s4d-loader-text {
    font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: #2d1b4e;
    letter-spacing: 0.005em;
    text-align: center;
    margin: 0;
}

.s4d-loader-subtext {
    font-family: 'Plus Jakarta Sans', system-ui, -apple-system, sans-serif;
    font-size: 0.78rem;
    font-weight: 500;
    color: #6c757d;
    text-align: center;
    margin: -0.25rem 0 0;
    letter-spacing: 0.01em;
}

/* Respect reduced-motion preferences. */
@media (prefers-reduced-motion: reduce) {
    .s4d-loader-overlay,
    .s4d-loader-card,
    .s4d-loader-spinner::before,
    .s4d-loader-spinner::after {
        transition: none !important;
        animation-duration: 1.6s !important;
    }
}