/* ============================================================================
   SIKKHALAY UNIFIED NOTIFICATION SYSTEM — MODERN DESIGN SYSTEM STYLESHEET
   Supports Light & Dark themes, responsive layout, toasts, and mobile drawers.
   ============================================================================ */

:root {
    --sn-primary: #059669;
    --sn-primary-hover: #047857;
    --sn-bg-surface: #FFFFFF;
    --sn-bg-hover: #F8FAFC;
    --sn-border: #E2E8F0;
    --sn-text-main: #0F172A;
    --sn-text-muted: #64748B;
    --sn-text-subtle: #94A3B8;
    --sn-unread-bg: #F0FDF4;
    --sn-unread-border: #BBF7D0;
    --sn-shadow-dropdown: 0 16px 36px -4px rgba(15, 23, 42, 0.16), 0 0 0 1px rgba(15, 23, 42, 0.06);
    --sn-shadow-toast: 0 12px 28px -4px rgba(15, 23, 42, 0.2), 0 0 0 1px rgba(15, 23, 42, 0.08);
}

[data-theme="dark"] {
    --sn-primary: #10B981;
    --sn-primary-hover: #059669;
    --sn-bg-surface: #1E293B;
    --sn-bg-hover: #334155;
    --sn-border: #334155;
    --sn-text-main: #F8FAFC;
    --sn-text-muted: #94A3B8;
    --sn-text-subtle: #64748B;
    --sn-unread-bg: rgba(16, 185, 129, 0.08);
    --sn-unread-border: rgba(16, 185, 129, 0.25);
    --sn-shadow-dropdown: 0 20px 40px -4px rgba(0, 0, 0, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.08);
    --sn-shadow-toast: 0 16px 32px -4px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.1);
}

/* 1. BELL BUTTON BADGE PULSE */
.sn-bell-btn {
    position: relative !important;
    cursor: pointer !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    transition: transform 0.15s ease, opacity 0.15s ease;
}

.sn-bell-btn:hover {
    transform: scale(1.06);
}

.sn-badge {
    position: absolute !important;
    top: -4px !important;
    right: -6px !important;
    min-width: 18px !important;
    height: 18px !important;
    padding: 0 5px !important;
    background: #E11D48 !important;
    color: #FFFFFF !important;
    font-size: 11px !important;
    font-weight: 700 !important;
    line-height: 18px !important;
    text-align: center !important;
    border-radius: 9999px !important;
    box-shadow: 0 2px 6px rgba(225, 29, 72, 0.4) !important;
    border: 2px solid var(--sn-bg-surface) !important;
    pointer-events: none !important;
    display: inline-flex !important;
    align-items: center !important;
    justify-content: center !important;
    z-index: 10 !important;
    animation: sn-badge-pop 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.sn-badge.hidden {
    display: none !important;
}

@keyframes sn-badge-pop {
    0% { transform: scale(0.5); opacity: 0; }
    100% { transform: scale(1); opacity: 1; }
}

/* 2. DROPDOWN WRAPPER & CONTAINER */
.sn-dropdown-backdrop {
    position: fixed !important;
    inset: 0 !important;
    top: 0 !important;
    left: 0 !important;
    right: 0 !important;
    bottom: 0 !important;
    width: 100vw !important;
    height: 100vh !important;
    background: rgba(15, 23, 42, 0.35) !important;
    backdrop-filter: blur(2px) !important;
    -webkit-backdrop-filter: blur(2px) !important;
    z-index: 2147483646 !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transition: opacity 0.15s ease, visibility 0.15s ease;
}

.sn-dropdown-backdrop.active {
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
}

.sn-dropdown-panel {
    position: fixed !important;
    top: 65px;
    right: 20px;
    width: 380px !important;
    max-width: calc(100vw - 24px) !important;
    background: var(--sn-bg-surface) !important;
    border-radius: 16px !important;
    border: 1px solid var(--sn-border) !important;
    box-shadow: var(--sn-shadow-dropdown) !important;
    z-index: 2147483647 !important;
    display: flex !important;
    flex-direction: column !important;
    overflow: hidden !important;
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-8px) scale(0.98);
    transition: opacity 0.15s ease, transform 0.15s ease;
    font-family: inherit !important;
}

.sn-dropdown-panel.open {
    display: flex !important;
    opacity: 1 !important;
    visibility: visible !important;
    pointer-events: auto !important;
    transform: translateY(0) scale(1) !important;
}

/* 3. DROPDOWN HEADER */
.sn-header {
    padding: 14px 18px;
    border-bottom: 1px solid var(--sn-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    background: var(--sn-bg-surface);
}

.sn-header-left {
    display: flex;
    align-items: center;
    gap: 8px;
}

.sn-header-title {
    font-size: 15px;
    font-weight: 700;
    color: var(--sn-text-main);
    margin: 0;
}

.sn-unread-pill {
    background: rgba(5, 150, 105, 0.12);
    color: var(--sn-primary);
    font-size: 11px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 9999px;
}

.sn-header-actions {
    display: flex;
    align-items: center;
    gap: 10px;
}

.sn-btn-text {
    background: none;
    border: none;
    padding: 0;
    font-size: 12px;
    font-weight: 600;
    color: var(--sn-primary);
    cursor: pointer;
    transition: opacity 0.15s ease;
}

.sn-btn-text:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.sn-sound-toggle {
    background: none;
    border: none;
    color: var(--sn-text-muted);
    cursor: pointer;
    font-size: 13px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 4px;
    border-radius: 6px;
    transition: all 0.15s ease;
}

.sn-sound-toggle:hover {
    color: var(--sn-text-main);
    background: var(--sn-bg-hover);
}

/* 4. FILTER TABS */
.sn-filter-strip {
    display: flex;
    gap: 6px;
    padding: 10px 16px;
    background: var(--sn-bg-hover);
    border-bottom: 1px solid var(--sn-border);
    overflow-x: auto;
    scrollbar-width: none;
}

.sn-filter-strip::-webkit-scrollbar {
    display: none;
}

.sn-filter-chip {
    padding: 4px 12px;
    border-radius: 9999px;
    font-size: 11.5px;
    font-weight: 600;
    color: var(--sn-text-muted);
    background: var(--sn-bg-surface);
    border: 1px solid var(--sn-border);
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.15s ease;
}

.sn-filter-chip:hover {
    color: var(--sn-text-main);
    border-color: var(--sn-primary);
}

.sn-filter-chip.active {
    background: var(--sn-primary);
    color: #FFFFFF;
    border-color: var(--sn-primary);
}

/* 5. NOTIFICATION LIST CONTAINER */
.sn-list {
    max-height: 400px;
    overflow-y: auto;
    overscroll-behavior: contain;
    display: flex;
    flex-direction: column;
}

.sn-list::-webkit-scrollbar {
    width: 5px;
}

.sn-list::-webkit-scrollbar-thumb {
    background: var(--sn-border);
    border-radius: 4px;
}

/* 6. NOTIFICATION ITEM CARD */
.sn-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 12px 16px;
    border-bottom: 1px solid var(--sn-border);
    background: var(--sn-bg-surface);
    transition: background 0.15s ease;
    cursor: pointer;
    position: relative;
    text-decoration: none;
    color: inherit;
}

.sn-item:hover {
    background: var(--sn-bg-hover);
}

.sn-item.unread {
    background: var(--sn-unread-bg);
}

.sn-item.unread::before {
    content: '';
    position: absolute;
    left: 4px;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    border-radius: 9999px;
    background: var(--sn-primary);
}

.sn-icon-box {
    width: 36px;
    height: 36px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 15px;
    flex-shrink: 0;
    color: #FFFFFF;
}

.sn-icon-box.sn-cat-exam { background: linear-gradient(135deg, #F59E0B, #EA580C); }
.sn-icon-box.sn-cat-fee { background: linear-gradient(135deg, #059669, #0D9488); }
.sn-icon-box.sn-cat-academic { background: linear-gradient(135deg, #4F46E5, #3B82F6); }
.sn-icon-box.sn-cat-attendance { background: linear-gradient(135deg, #8B5CF6, #6366F1); }
.sn-icon-box.sn-cat-notice { background: linear-gradient(135deg, #0284C7, #06B6D4); }
.sn-icon-box.sn-cat-system { background: linear-gradient(135deg, #64748B, #475569); }
.sn-icon-box.sn-cat-tuition { background: linear-gradient(135deg, #10B981, #047857); }
.sn-icon-box.sn-cat-admission { background: linear-gradient(135deg, #D97706, #B45309); }
.sn-icon-box.sn-cat-staff { background: linear-gradient(135deg, #E11D48, #BE123C); }
.sn-icon-box.sn-cat-subscriptions { background: linear-gradient(135deg, #7C3AED, #9333EA); }
.sn-icon-box.sn-cat-institutions { background: linear-gradient(135deg, #2563EB, #1D4ED8); }
.sn-icon-box.sn-cat-teachers { background: linear-gradient(135deg, #059669, #10B981); }

.sn-content {
    flex: 1;
    min-width: 0;
}

.sn-title-row {
    display: flex;
    align-items: baseline;
    justify-content: space-between;
    gap: 8px;
    margin-bottom: 3px;
}

.sn-item-title {
    font-size: 13.5px;
    font-weight: 600;
    color: var(--sn-text-main);
    line-height: 1.35;
    margin: 0;
}

.sn-item-time {
    font-size: 11px;
    color: var(--sn-text-subtle);
    white-space: nowrap;
    flex-shrink: 0;
}

.sn-item-msg {
    font-size: 12.5px;
    color: var(--sn-text-muted);
    line-height: 1.45;
    margin: 0;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.sn-item-del {
    background: none;
    border: none;
    color: var(--sn-text-subtle);
    font-size: 12px;
    cursor: pointer;
    padding: 4px;
    border-radius: 4px;
    opacity: 0;
    transition: all 0.15s ease;
    align-self: flex-start;
}

.sn-item:hover .sn-item-del {
    opacity: 1;
}

.sn-item-del:hover {
    color: #E11D48;
    background: rgba(225, 29, 72, 0.1);
}

/* 7. EMPTY STATE */
.sn-empty-state {
    padding: 40px 20px;
    text-align: center;
    color: var(--sn-text-muted);
}

.sn-empty-icon {
    font-size: 36px;
    color: var(--sn-text-subtle);
    margin-bottom: 10px;
    opacity: 0.6;
}

.sn-empty-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--sn-text-main);
    margin-bottom: 4px;
}

.sn-empty-subtitle {
    font-size: 12px;
}

/* 8. FOOTER */
.sn-footer {
    padding: 10px 16px;
    border-top: 1px solid var(--sn-border);
    background: var(--sn-bg-surface);
    display: flex;
    align-items: center;
    justify-content: center;
}

.sn-footer-link {
    font-size: 12px;
    font-weight: 600;
    color: var(--sn-primary);
    text-decoration: none;
}

.sn-footer-link:hover {
    text-decoration: underline;
}

/* 9. FLOATING TOAST NOTIFICATION POPUP */
.sn-toast-container {
    position: fixed !important;
    bottom: 24px !important;
    right: 24px !important;
    z-index: 2147483647 !important;
    display: flex !important;
    flex-direction: column !important;
    gap: 12px !important;
    pointer-events: none !important;
    max-width: 380px !important;
    width: calc(100% - 48px) !important;
}

.sn-toast {
    background: var(--sn-bg-surface);
    border: 1px solid var(--sn-border);
    border-radius: 14px;
    padding: 14px 16px;
    box-shadow: var(--sn-shadow-toast);
    display: flex;
    align-items: flex-start;
    gap: 12px;
    pointer-events: auto;
    cursor: pointer;
    animation: sn-toast-in 0.35s cubic-bezier(0.16, 1, 0.3, 1);
    transition: transform 0.2s ease, opacity 0.2s ease;
    position: relative;
    overflow: hidden;
}

.sn-toast.sn-toast-hiding {
    opacity: 0;
    transform: translateY(10px) scale(0.95);
}

.sn-toast-progress {
    position: absolute;
    bottom: 0;
    left: 0;
    height: 3px;
    background: var(--sn-primary);
    width: 100%;
    animation: sn-progress-drain 5.5s linear forwards;
}

@keyframes sn-toast-in {
    0% { transform: translateY(20px) scale(0.92); opacity: 0; }
    100% { transform: translateY(0) scale(1); opacity: 1; }
}

@keyframes sn-progress-drain {
    0% { width: 100%; }
    100% { width: 0%; }
}

/* 10. RESPONSIVE MOBILE ADJUSTMENT */
@media (max-width: 640px) {
    .sn-dropdown-panel {
        position: fixed !important;
        top: auto !important;
        bottom: 0 !important;
        left: 0 !important;
        right: 0 !important;
        width: 100% !important;
        max-width: 100% !important;
        border-radius: 20px 20px 0 0 !important;
        transform: translateY(100%) !important;
    }

    .sn-dropdown-panel.open {
        transform: translateY(0) !important;
    }

    .sn-toast-container {
        bottom: 16px !important;
        right: 16px !important;
        left: 16px !important;
        width: auto !important;
        max-width: 100% !important;
    }
}