/* =====================================================
   THEME - Visual improvements, Dark Mode, Loading
   ===================================================== */

/* ---------- CSS VARIABLES ---------- */

:root {
    --brand-gradient: linear-gradient(135deg, #2563eb 0%, #7c3aed 100%);
    --transition-fast: 0.15s ease;
    --transition-medium: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ---------- SVG LOGO ---------- */

.brand-icon-svg {
    width: 60px;
    height: 60px;
    flex-shrink: 0;
    border-radius: 16px;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
    transition: transform var(--transition-medium);
}

.brand-icon-svg:hover {
    transform: scale(1.05) rotate(-3deg);
}

.dashboard-logo-svg {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.25);
}

/* ---------- LOADING SCREEN ---------- */

#appLoader {
    position: fixed;
    inset: 0;
    background: linear-gradient(135deg, #f8fafc 0%, #eff6ff 100%);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 24px;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

#appLoader.hidden {
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
}

.app-loader-spinner {
    width: 64px;
    height: 64px;
    border: 4px solid rgba(37, 99, 235, 0.15);
    border-top-color: #2563eb;
    border-radius: 50%;
    animation: appLoaderSpin 0.9s linear infinite;
}

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

.app-loader-text {
    color: #1d4ed8;
    font-size: 15px;
    font-weight: 600;
    letter-spacing: 0.5px;
    animation: appLoaderPulse 1.5s ease-in-out infinite;
}

@keyframes appLoaderPulse {
    0%, 100% { opacity: 0.6; }
    50%      { opacity: 1; }
}

.app-loader-logo {
    width: 80px;
    height: 80px;
    border-radius: 20px;
    margin-bottom: 8px;
    animation: appLoaderFloat 2s ease-in-out infinite;
}

@keyframes appLoaderFloat {
    0%, 100% { transform: translateY(0); }
    50%      { transform: translateY(-8px); }
}

/* ---------- DARK MODE TOGGLE BUTTON ---------- */

.theme-toggle-btn {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    border: 1px solid #e5e7eb;
    background: #ffffff;
    color: #374151;
    font-size: 20px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.theme-toggle-btn:hover {
    background: #f9fafb;
    border-color: #d1d5db;
    transform: scale(1.05);
}

.theme-toggle-btn:active {
    transform: scale(0.95);
}

/* ---------- SMOOTH TRANSITIONS ---------- */

.management-section,
.dashboard-card,
.class-card,
.lesson-item,
.assignment-item,
.announcement-item,
.note-item,
.notification-item,
.grade-item,
.student-item,
.conversation-card {
    transition: transform var(--transition-medium), 
                box-shadow var(--transition-medium), 
                background-color var(--transition-medium),
                border-color var(--transition-medium) !important;
}

.modal {
    transition: transform var(--transition-medium), 
                opacity var(--transition-medium);
}

body {
    transition: background-color var(--transition-slow), 
                color var(--transition-slow);
}

/* Fade-in animation for loaded content */

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(12px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.management-section,
.class-card,
.lesson-item,
.assignment-item {
    animation: fadeInUp 0.4s ease-out;
}

/* =====================================================
   DARK MODE
   ===================================================== */

body.dark {
    background: #0f172a;
    color: #f1f5f9;
}

body.dark .dashboard-page,
body.dark .auth-page {
    background: #0f172a;
}

/* --- Cards & Panels --- */

body.dark .dashboard-header,
body.dark .dashboard-welcome,
body.dark .section-header,
body.dark .form-panel,
body.dark .class-card,
body.dark .modal,
body.dark .dashboard-card,
body.dark .empty-box,
body.dark .loading-box,
body.dark .student-item,
body.dark .lesson-item,
body.dark .assignment-item,
body.dark .announcement-item,
body.dark .note-item,
body.dark .notification-item,
body.dark .grade-item,
body.dark .submission-card,
body.dark .conversation-card,
body.dark .gradebook-wrap,
body.dark .gradebook-stat,
body.dark .grade-stat-card,
body.dark .auth-card,
body.dark .selection-card {
    background: #1e293b;
    border-color: #334155;
    color: #f1f5f9;
}

body.dark .class-info {
    border-color: #334155;
}

body.dark .class-info-row,
body.dark .class-actions,
body.dark .lesson-actions,
body.dark .assignment-actions,
body.dark .announcement-actions,
body.dark .note-actions,
body.dark .notification-actions,
body.dark .note-meta,
body.dark .notification-meta,
body.dark .announcement-meta {
    border-color: #334155;
}

/* --- Text --- */

body.dark h1,
body.dark h2,
body.dark h3,
body.dark h4,
body.dark .dashboard-title,
body.dark .class-title-area h3,
body.dark .student-name,
body.dark .lesson-title,
body.dark .assignment-title,
body.dark .announcement-title,
body.dark .note-title,
body.dark .notification-title,
body.dark .grade-item-title,
body.dark .conversation-name,
body.dark .gradebook-student-name,
body.dark .gradebook-stat-value,
body.dark .modal-header h2 {
    color: #f1f5f9;
}

body.dark p,
body.dark span,
body.dark .dashboard-subtitle,
body.dark .muted,
body.dark .class-info-row span,
body.dark .student-username,
body.dark .student-date,
body.dark .lesson-date,
body.dark .lesson-description,
body.dark .assignment-description,
body.dark .assignment-meta,
body.dark .announcement-content,
body.dark .note-content,
body.dark .notification-content,
body.dark .conversation-last,
body.dark .modal-subtitle,
body.dark .gradebook-stat-label,
body.dark .class-title-area span,
body.dark .section-header p,
body.dark .dashboard-welcome p {
    color: #94a3b8;
}

body.dark .gradebook-stat-value {
    color: #f1f5f9;
}

/* --- Inputs --- */

body.dark input,
body.dark textarea,
body.dark select,
body.dark .chat-input {
    background: #334155;
    border-color: #475569;
    color: #f1f5f9;
}

body.dark input:focus,
body.dark textarea:focus,
body.dark select:focus,
body.dark .chat-input:focus {
    background: #334155;
    border-color: #60a5fa;
    box-shadow: 0 0 0 3px rgba(96, 165, 250, 0.2);
}

body.dark input::placeholder,
body.dark textarea::placeholder {
    color: #64748b;
}

body.dark label,
body.dark .form-panel label,
body.dark .assignment-form label,
body.dark .note-form label,
body.dark .announcement-form label,
body.dark .notification-form label,
body.dark .lesson-form label {
    color: #cbd5e1;
}

/* --- Secondary Buttons --- */

body.dark .secondary-btn,
body.dark .theme-toggle-btn,
body.dark .modal-close-btn,
body.dark .student-action-btn,
body.dark .lesson-actions button,
body.dark .assignment-actions button,
body.dark .announcement-actions button,
body.dark .note-actions button,
body.dark .notification-actions button {
    background: #334155;
    border-color: #475569;
    color: #cbd5e1;
}

body.dark .secondary-btn:hover,
body.dark .theme-toggle-btn:hover,
body.dark .modal-close-btn:hover,
body.dark .student-action-btn:hover,
body.dark .lesson-actions button:hover,
body.dark .assignment-actions button:hover,
body.dark .announcement-actions button:hover,
body.dark .note-actions button:hover,
body.dark .notification-actions button:hover {
    background: #475569;
    border-color: #64748b;
}

body.dark .bell-btn {
    background: #334155;
    border-color: #475569;
    color: #cbd5e1;
}

body.dark .bell-btn:hover {
    background: #475569;
}

/* --- Hover states --- */

body.dark .student-item:hover,
body.dark .lesson-item:hover,
body.dark .assignment-item:hover,
body.dark .announcement-item:hover,
body.dark .note-item:hover,
body.dark .notification-item:hover,
body.dark .grade-item:hover,
body.dark .conversation-card:hover {
    background: #334155;
    border-color: #475569;
}

body.dark .class-card:hover {
    box-shadow: 0 10px 28px rgba(0, 0, 0, 0.4);
}

body.dark .dashboard-card:hover {
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.4);
}

/* --- Table (Gradebook) --- */

body.dark .gradebook-table thead th {
    background: #1e293b;
    color: #cbd5e1;
    border-bottom-color: #334155;
}

body.dark .gradebook-table th,
body.dark .gradebook-table td {
    border-bottom-color: #334155;
}

body.dark .gradebook-student-col,
body.dark .gradebook-table thead .gradebook-student-col,
body.dark .gradebook-table tfoot .gradebook-student-col,
body.dark .gradebook-table tfoot td,
body.dark .gradebook-avg-col,
body.dark .gradebook-table thead .gradebook-avg-col {
    background: #1e293b;
    color: #cbd5e1;
    border-color: #334155;
}

body.dark .gradebook-cell.empty,
body.dark .gradebook-cell.avg-cell {
    background: #334155;
    color: #94a3b8;
    border-color: #475569;
}

body.dark .gradebook-col-num {
    background: #334155;
    color: #94a3b8;
}

/* --- Chat --- */

body.dark .chat-messages {
    background: #0f172a;
}

body.dark .chat-bubble-row.theirs .chat-bubble {
    background: #334155;
    color: #f1f5f9;
    border-color: #475569;
}

body.dark .chat-form {
    background: #1e293b;
    border-color: #334155;
}

body.dark .chat-empty {
    background: #0f172a;
    color: #94a3b8;
}

body.dark .chat-empty p {
    color: #cbd5e1;
}

/* --- Modals overlay --- */

body.dark .modal-overlay {
    background: rgba(0, 0, 0, 0.75);
}

/* --- Loading screen dark mode --- */

body.dark #appLoader {
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
}

body.dark .app-loader-text {
    color: #60a5fa;
}

body.dark .app-loader-spinner {
    border-color: rgba(96, 165, 250, 0.2);
    border-top-color: #60a5fa;
}

/* --- Grade stat card dark --- */

body.dark .grade-stat-card.neutral {
    background: #1e293b;
    border-color: #334155;
}

body.dark .grade-stat-card.excellent {
    background: rgba(22, 163, 74, 0.15);
    border-color: rgba(34, 197, 94, 0.4);
}

body.dark .grade-stat-card.good {
    background: rgba(37, 99, 235, 0.15);
    border-color: rgba(59, 130, 246, 0.4);
}

body.dark .grade-stat-card.average {
    background: rgba(217, 119, 6, 0.15);
    border-color: rgba(245, 158, 11, 0.4);
}

body.dark .grade-stat-card.fail {
    background: rgba(220, 38, 38, 0.15);
    border-color: rgba(239, 68, 68, 0.4);
}

body.dark .grade-stat-value {
    color: #f1f5f9;
}

/* --- Auth pages dark --- */

body.dark .auth-card h2 {
    color: #f1f5f9;
}

body.dark .brand h1 {
    color: #60a5fa;
}

body.dark .role-tabs {
    background: #334155;
}

body.dark .role-tab {
    color: #94a3b8;
}

body.dark .role-tab.active {
    background: #1e293b;
    color: #60a5fa;
}

body.dark .back-btn,
body.dark .link-btn {
    color: #60a5fa;
}

/* --- Badges dark --- */

body.dark .assignment-status-badge.not-submitted {
    background: rgba(220, 38, 38, 0.2);
    color: #fca5a5;
    border-color: rgba(220, 38, 38, 0.4);
}

body.dark .assignment-status-badge.waiting {
    background: rgba(217, 119, 6, 0.2);
    color: #fcd34d;
    border-color: rgba(217, 119, 6, 0.4);
}

body.dark .assignment-status-badge.graded {
    background: rgba(22, 163, 74, 0.2);
    color: #86efac;
    border-color: rgba(22, 163, 74, 0.4);
}

body.dark .assignment-status-badge.overdue {
    background: #334155;
    color: #94a3b8;
    border-color: #475569;
}

/* --- Notes / Announcements / Notifications dark --- */

body.dark .note-item.type-praise {
    background: rgba(22, 163, 74, 0.1);
}

body.dark .note-item.type-warning {
    background: rgba(220, 38, 38, 0.1);
}

body.dark .note-item.type-info {
    background: #1e293b;
}

body.dark .announcement-item.priority-important {
    background: rgba(217, 119, 6, 0.1);
}

body.dark .announcement-item.priority-urgent {
    background: rgba(220, 38, 38, 0.1);
}

body.dark .notification-item.type-success {
    background: rgba(22, 163, 74, 0.1);
}

body.dark .notification-item.type-warning {
    background: rgba(217, 119, 6, 0.1);
}

/* --- Scrollbar dark --- */

body.dark ::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}

body.dark ::-webkit-scrollbar-track {
    background: #0f172a;
}

body.dark ::-webkit-scrollbar-thumb {
    background: #334155;
    border-radius: 5px;
}

body.dark ::-webkit-scrollbar-thumb:hover {
    background: #475569;
}

/* --- Responsive tweak for theme toggle --- */

@media (max-width: 600px) {
    .theme-toggle-btn {
        width: 42px;
        height: 42px;
    }
}
/* =====================================================
   PWA — Install Button + iOS Hint
   ===================================================== */

.pwa-install-btn {
    height: 44px;
    padding: 0 16px;
    border: none;
    border-radius: 12px;
    background: linear-gradient(135deg, #2563eb, #7c3aed);
    color: #ffffff;
    font-size: 14px;
    font-weight: 700;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.2s;
    font-family: inherit;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
    animation: pwaBtnPulse 2.5s ease-in-out infinite;
}

.pwa-install-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(37, 99, 235, 0.4);
}

.pwa-install-btn:active {
    transform: translateY(0) scale(0.97);
}

@keyframes pwaBtnPulse {
    0%, 100% { box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3); }
    50%      { box-shadow: 0 6px 18px rgba(124, 58, 237, 0.4); }
}


/* ===== iOS Hint ===== */

.pwa-ios-hint {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    display: flex;
    align-items: flex-end;
    justify-content: center;
    padding: 20px;
    z-index: 10000;
    animation: modalFadeIn 0.25s ease-out;
}

.pwa-ios-hint-content {
    background: #ffffff;
    border-radius: 20px;
    padding: 24px 22px;
    max-width: 400px;
    width: 100%;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    animation: slideUpIos 0.3s ease-out;
    margin-bottom: 20px;
}

@keyframes slideUpIos {
    from { transform: translateY(30px); opacity: 0; }
    to   { transform: translateY(0);    opacity: 1; }
}

.pwa-ios-hint-content h3 {
    margin: 0 0 12px;
    font-size: 19px;
    color: #111827;
}

.pwa-ios-hint-content p {
    margin: 0 0 18px;
    color: #4b5563;
    font-size: 14.5px;
    line-height: 1.8;
}

.pwa-ios-hint-content p strong {
    color: #1d4ed8;
}

.pwa-ios-hint-content button {
    width: 100%;
    height: 46px;
    border: none;
    border-radius: 10px;
    background: #2563eb;
    color: #ffffff;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    font-family: inherit;
    transition: background 0.15s;
}

.pwa-ios-hint-content button:hover {
    background: #1d4ed8;
}

body.dark .pwa-ios-hint-content {
    background: #1e293b;
}

body.dark .pwa-ios-hint-content h3 {
    color: #f1f5f9;
}

body.dark .pwa-ios-hint-content p {
    color: #cbd5e1;
}


/* ===== Responsive ===== */

@media (max-width: 600px) {

    .pwa-install-btn {
        height: 42px;
        padding: 0 12px;
        font-size: 13px;
        flex: 1;
    }
}