/* ==========================================================================
   Mr. Maths LMS - Quantum Mathematical Preloader System
   Universal Dual-Theme (Light Theme Default | Ultra-Dark Cinematic Theme)
   ========================================================================== */

#preloader,
#loader.preloader-dark,
.preloader-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 9999999;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    opacity: 1;
    visibility: visible;
    transition: opacity 0.5s cubic-bezier(0.4, 0, 0.2, 1), visibility 0.5s ease;
    pointer-events: all;
    user-select: none;
    overflow: hidden;
}

#preloader.fade-out,
#loader.fade-out {
    opacity: 0 !important;
    visibility: hidden !important;
    pointer-events: none !important;
}

/* Ensure dialogs, SweetAlert2 alerts, and modals are ALWAYS rendered above the preloader */
.swal2-container {
    z-index: 100000000 !important;
}
.modal {
    z-index: 10000000 !important;
}
.modal-backdrop {
    z-index: 9999998 !important;
}
.crop-modal-overlay {
    z-index: 10000000 !important;
}

/* ==========================================================================
   1. DEFAULT THEME: Modern Frosted Light Theme
   (Matches current Light Theme LMS: clean slate/white, royal blue, cyan)
   ========================================================================== */

#preloader {
    background: radial-gradient(circle at center, rgba(255, 255, 255, 0.98) 0%, rgba(241, 245, 249, 0.98) 100%);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
}

/* Light Ambient Radial Glow */
#preloader .preloader-ambient-glow {
    position: absolute;
    width: 380px;
    height: 380px;
    background: radial-gradient(circle, rgba(0, 123, 255, 0.12) 0%, rgba(56, 189, 248, 0.08) 45%, transparent 70%);
    filter: blur(45px);
    pointer-events: none;
    z-index: 1;
    animation: preloaderPulseAmbient 4s ease-in-out infinite alternate;
}

/* Preloader Content Wrapper */
.preloader-inner {
    position: relative;
    z-index: 10;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

/* Concentric Orbital Rings Container */
.preloader-orbital {
    position: relative;
    width: 140px;
    height: 140px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.orbit-ring {
    position: absolute;
    border-radius: 50%;
    pointer-events: none;
}

/* Outer Ring (Royal Blue & Soft Cyan Dashed) */
#preloader .orbit-ring-1 {
    width: 140px;
    height: 140px;
    border: 2px dashed rgba(0, 123, 255, 0.55);
    border-top-color: #0056b3;
    border-bottom-color: rgba(56, 189, 248, 0.35);
    animation: preloaderOrbitClockwise 3.2s linear infinite;
    box-shadow: 0 0 16px rgba(0, 123, 255, 0.12);
}

#preloader .orbit-ring-1::before {
    content: '';
    position: absolute;
    top: 5px;
    left: 20px;
    width: 8px;
    height: 8px;
    background: #007bff;
    border-radius: 50%;
    box-shadow: 0 0 10px rgba(0, 123, 255, 0.7);
}

/* Middle Ring (Sky Cyan & Royal Blue) */
#preloader .orbit-ring-2 {
    width: 114px;
    height: 114px;
    border: 2px solid transparent;
    border-right-color: #007bff;
    border-left-color: #0284c7;
    animation: preloaderOrbitCounter 2.2s cubic-bezier(0.4, 0, 0.2, 1) infinite;
    filter: drop-shadow(0 0 6px rgba(0, 123, 255, 0.25));
}

#preloader .orbit-ring-2::after {
    content: '';
    position: absolute;
    bottom: 8px;
    right: 12px;
    width: 6px;
    height: 6px;
    background: #004fe1;
    border-radius: 50%;
    box-shadow: 0 0 8px rgba(0, 79, 225, 0.6);
}

/* Inner Accent Ring (Subtle Gold Ring for Mathematical Distinction) */
#preloader .orbit-ring-3 {
    width: 92px;
    height: 92px;
    border: 1.5px solid rgba(217, 119, 6, 0.45);
    border-top-color: transparent;
    border-bottom-color: transparent;
    animation: preloaderOrbitClockwise 4.8s linear infinite;
}

/* Central Logo Badge */
#preloader .preloader-logo-wrap {
    position: relative;
    width: 68px;
    height: 68px;
    border-radius: 50%;
    background: #ffffff;
    padding: 3px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 
        0 8px 25px rgba(0, 123, 255, 0.2),
        0 2px 8px rgba(0, 0, 0, 0.06),
        inset 0 0 8px rgba(0, 123, 255, 0.1);
    border: 2px solid rgba(0, 123, 255, 0.22);
    animation: preloaderLogoBreatheLight 2.6s ease-in-out infinite;
    z-index: 5;
}

.preloader-logo {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: 50%;
    display: block;
}

/* Brand Typography */
.preloader-brand {
    margin-bottom: 20px;
}

#preloader .preloader-title {
    font-family: 'Outfit', 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 1.35rem;
    font-weight: 800;
    letter-spacing: 0.8px;
    margin: 0 0 4px 0;
    background: linear-gradient(135deg, #0b1e48 20%, #0056b3 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

#preloader .preloader-sub {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: #0284c7;
    margin: 0;
}

/* Light Indeterminate Progress Bar */
#preloader .preloader-progress {
    width: 160px;
    height: 3.5px;
    background: rgba(0, 123, 255, 0.12);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.05);
}

#preloader .preloader-progress-bar {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 45%;
    background: linear-gradient(90deg, #0056b3, #007bff, #38bdf8, #007bff);
    background-size: 200% 100%;
    border-radius: 10px;
    box-shadow: 0 0 10px rgba(0, 123, 255, 0.4);
    animation: preloaderTrackSlide 1.6s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

/* Legacy fallback for simple <div id="preloader"><img class="loader-logo"></div> */
#preloader:not(:has(.preloader-inner)) {
    background: radial-gradient(circle at center, #ffffff 0%, #f1f5f9 100%) !important;
}

#preloader > .loader-logo,
#preloader > img:not(.preloader-logo) {
    width: 76px !important;
    height: 76px !important;
    object-fit: contain !important;
    border-radius: 50% !important;
    padding: 3px !important;
    background: #ffffff !important;
    box-shadow: 0 8px 30px rgba(0, 123, 255, 0.25) !important;
    border: 2px solid rgba(0, 123, 255, 0.2) !important;
    animation: preloaderLogoBreatheLight 2s ease-in-out infinite !important;
}


/* ==========================================================================
   2. DARK THEME PRELOADER
   (Saved for Future Dark Mode AND actively used for Admin Panel)
   Activated by: .preloader-dark, #preloader.dark-theme, #loader.preloader-dark,
                 body.dark-mode #preloader, [data-theme="dark"] #preloader, .dark #preloader
   ========================================================================== */

.preloader-dark,
#preloader.dark-theme,
#loader.preloader-dark,
body.dark-mode #preloader,
[data-theme="dark"] #preloader,
.dark #preloader {
    background: radial-gradient(circle at center, rgba(12, 26, 61, 0.6) 0%, rgba(6, 11, 24, 0.72) 100%) !important;
    backdrop-filter: blur(12px) saturate(180%) !important;
    -webkit-backdrop-filter: blur(12px) saturate(180%) !important;
}

.preloader-dark .preloader-ambient-glow,
#preloader.dark-theme .preloader-ambient-glow,
#loader.preloader-dark .preloader-ambient-glow,
body.dark-mode #preloader .preloader-ambient-glow,
[data-theme="dark"] #preloader .preloader-ambient-glow {
    position: absolute;
    width: 380px;
    height: 380px;
    background: radial-gradient(circle, rgba(0, 123, 255, 0.28) 0%, rgba(56, 189, 248, 0.12) 40%, transparent 70%) !important;
    filter: blur(50px) !important;
    pointer-events: none;
    z-index: 1;
    animation: preloaderPulseAmbient 4s ease-in-out infinite alternate;
}

.preloader-dark .orbit-ring-1,
#preloader.dark-theme .orbit-ring-1,
#loader.preloader-dark .orbit-ring-1,
body.dark-mode #preloader .orbit-ring-1,
[data-theme="dark"] #preloader .orbit-ring-1 {
    width: 140px;
    height: 140px;
    border: 2px dashed rgba(56, 189, 248, 0.7) !important;
    border-top-color: #007bff !important;
    border-bottom-color: rgba(0, 123, 255, 0.25) !important;
    animation: preloaderOrbitClockwise 3.2s linear infinite;
    box-shadow: 0 0 20px rgba(0, 123, 255, 0.25) !important;
}

.preloader-dark .orbit-ring-1::before,
#preloader.dark-theme .orbit-ring-1::before,
#loader.preloader-dark .orbit-ring-1::before,
body.dark-mode #preloader .orbit-ring-1::before,
[data-theme="dark"] #preloader .orbit-ring-1::before {
    content: '';
    position: absolute;
    top: 5px;
    left: 20px;
    width: 8px;
    height: 8px;
    background: #38bdf8 !important;
    border-radius: 50%;
    box-shadow: 0 0 12px #38bdf8, 0 0 20px #007bff !important;
}

.preloader-dark .orbit-ring-2,
#preloader.dark-theme .orbit-ring-2,
#loader.preloader-dark .orbit-ring-2,
body.dark-mode #preloader .orbit-ring-2,
[data-theme="dark"] #preloader .orbit-ring-2 {
    width: 114px;
    height: 114px;
    border: 2px solid transparent !important;
    border-right-color: #38bdf8 !important;
    border-left-color: rgba(0, 229, 255, 0.9) !important;
    animation: preloaderOrbitCounter 2.2s cubic-bezier(0.4, 0, 0.2, 1) infinite;
    filter: drop-shadow(0 0 8px rgba(56, 189, 248, 0.5)) !important;
}

.preloader-dark .orbit-ring-2::after,
#preloader.dark-theme .orbit-ring-2::after,
#loader.preloader-dark .orbit-ring-2::after,
body.dark-mode #preloader .orbit-ring-2::after,
[data-theme="dark"] #preloader .orbit-ring-2::after {
    content: '';
    position: absolute;
    bottom: 8px;
    right: 12px;
    width: 6px;
    height: 6px;
    background: #ffffff !important;
    border-radius: 50%;
    box-shadow: 0 0 10px #ffffff, 0 0 16px #38bdf8 !important;
}

.preloader-dark .orbit-ring-3,
#preloader.dark-theme .orbit-ring-3,
#loader.preloader-dark .orbit-ring-3,
body.dark-mode #preloader .orbit-ring-3,
[data-theme="dark"] #preloader .orbit-ring-3 {
    width: 92px;
    height: 92px;
    border: 1.5px solid rgba(245, 158, 11, 0.5) !important;
    border-top-color: transparent !important;
    border-bottom-color: transparent !important;
    animation: preloaderOrbitClockwise 4.8s linear infinite;
}

.preloader-dark .preloader-logo-wrap,
#preloader.dark-theme .preloader-logo-wrap,
#loader.preloader-dark .preloader-logo-wrap,
body.dark-mode #preloader .preloader-logo-wrap,
[data-theme="dark"] #preloader .preloader-logo-wrap {
    position: relative;
    width: 68px;
    height: 68px;
    border-radius: 50%;
    background: #0b1633 !important;
    padding: 3px;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 
        0 0 25px rgba(0, 123, 255, 0.55),
        0 0 50px rgba(56, 189, 248, 0.3),
        inset 0 0 12px rgba(0, 123, 255, 0.4) !important;
    border: none !important;
    animation: preloaderLogoBreatheDark 2.6s ease-in-out infinite;
    z-index: 5;
}

.preloader-dark .preloader-title,
#preloader.dark-theme .preloader-title,
#loader.preloader-dark .preloader-title,
body.dark-mode #preloader .preloader-title,
[data-theme="dark"] #preloader .preloader-title {
    font-family: 'Outfit', 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 1.35rem;
    font-weight: 800;
    letter-spacing: 0.8px;
    margin: 0 0 4px 0;
    background: linear-gradient(135deg, #ffffff 30%, #93c5fd 100%) !important;
    -webkit-background-clip: text !important;
    -webkit-text-fill-color: transparent !important;
    text-shadow: 0 2px 10px rgba(0, 123, 255, 0.3) !important;
}

.preloader-dark .preloader-sub,
#preloader.dark-theme .preloader-sub,
#loader.preloader-dark .preloader-sub,
body.dark-mode #preloader .preloader-sub,
[data-theme="dark"] #preloader .preloader-sub {
    font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, sans-serif;
    font-size: 0.72rem;
    font-weight: 700;
    letter-spacing: 2px;
    text-transform: uppercase;
    color: #38bdf8 !important;
    margin: 0;
    opacity: 0.95;
}

.preloader-dark .preloader-progress,
#preloader.dark-theme .preloader-progress,
#loader.preloader-dark .preloader-progress,
body.dark-mode #preloader .preloader-progress,
[data-theme="dark"] #preloader .preloader-progress {
    width: 160px;
    height: 3.5px;
    background: rgba(255, 255, 255, 0.12) !important;
    border-radius: 10px;
    overflow: hidden;
    position: relative;
    box-shadow: inset 0 1px 2px rgba(0, 0, 0, 0.4) !important;
}

.preloader-dark .preloader-progress-bar,
#preloader.dark-theme .preloader-progress-bar,
#loader.preloader-dark .preloader-progress-bar,
body.dark-mode #preloader .preloader-progress-bar,
[data-theme="dark"] #preloader .preloader-progress-bar {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    width: 45%;
    background: linear-gradient(90deg, #007bff, #38bdf8, #60a5fa, #38bdf8, #007bff) !important;
    background-size: 200% 100% !important;
    border-radius: 10px;
    box-shadow: 0 0 12px rgba(56, 189, 248, 0.8), 0 0 20px rgba(0, 123, 255, 0.6) !important;
    animation: preloaderTrackSlide 1.6s cubic-bezier(0.4, 0, 0.2, 1) infinite;
}

/* Legacy fallback under dark theme */
.preloader-dark:not(:has(.preloader-inner)),
#preloader.dark-theme:not(:has(.preloader-inner)),
#loader.preloader-dark:not(:has(.preloader-inner)),
body.dark-mode #preloader:not(:has(.preloader-inner)),
[data-theme="dark"] #preloader:not(:has(.preloader-inner)) {
    background: radial-gradient(circle at center, #0c1a3d 0%, #060b18 100%) !important;
}

.preloader-dark > .loader-logo,
#preloader.dark-theme > .loader-logo,
#loader.preloader-dark > .loader-logo,
body.dark-mode #preloader > .loader-logo,
[data-theme="dark"] #preloader > .loader-logo {
    background: #0b1633 !important;
    box-shadow: 0 0 35px rgba(0, 123, 255, 0.6), 0 0 70px rgba(56, 189, 248, 0.35) !important;
    border: none !important;
}


/* ==========================================================================
   3. KEYFRAME ANIMATIONS
   ========================================================================== */

@keyframes preloaderOrbitClockwise {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes preloaderOrbitCounter {
    0% { transform: rotate(360deg); }
    100% { transform: rotate(0deg); }
}

@keyframes preloaderLogoBreatheLight {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 8px 25px rgba(0, 123, 255, 0.2), 0 2px 8px rgba(0, 0, 0, 0.06);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 12px 35px rgba(0, 123, 255, 0.32), 0 4px 12px rgba(0, 0, 0, 0.08);
    }
}

@keyframes preloaderLogoBreatheDark {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 0 25px rgba(0, 123, 255, 0.55), 0 0 50px rgba(56, 189, 248, 0.3);
    }
    50% {
        transform: scale(1.06);
        box-shadow: 0 0 35px rgba(0, 123, 255, 0.8), 0 0 70px rgba(56, 189, 248, 0.5);
    }
}

@keyframes preloaderPulseAmbient {
    0% {
        transform: scale(0.92);
        opacity: 0.5;
    }
    100% {
        transform: scale(1.15);
        opacity: 0.85;
    }
}

@keyframes preloaderTrackSlide {
    0% {
        left: -45%;
        width: 30%;
    }
    50% {
        left: 35%;
        width: 55%;
    }
    100% {
        left: 105%;
        width: 30%;
    }
}