/* ================================================================
   Fee Reminder Generator – Custom Styles
   EduGenz | Professional School Management Tools
   ================================================================ */

/* ----------------------------------------------------------------
   CSS Custom Properties – Light Theme (Default)
   ---------------------------------------------------------------- */
:root {
    --primary:        #4f46e5;
    --primary-dark:   #3730a3;
    --primary-light:  #e0e7ff;
    --secondary:      #0ea5e9;
    --success:        #10b981;
    --warning:        #f59e0b;
    --danger:         #ef4444;

    --bg:             #f1f5f9;
    --card-bg:        #ffffff;
    --input-bg:       #ffffff;

    --text:           #1e293b;
    --text-muted:     #64748b;
    --border:         #e2e8f0;

    --header-bg:      linear-gradient(135deg, #4f46e5 0%, #0ea5e9 100%);
    --hero-bg:        linear-gradient(135deg, #e0e7ff 0%, #bfdbfe 100%);

    --shadow:         0 4px 24px rgba(79, 70, 229, 0.09);
    --shadow-sm:      0 2px 10px rgba(0, 0, 0, 0.07);
    --shadow-hover:   0 8px 30px rgba(79, 70, 229, 0.18);

    --radius:         14px;
    --radius-sm:      9px;
    --transition:     0.25s ease;
}

/* ----------------------------------------------------------------
   Dark Theme Override
   ---------------------------------------------------------------- */
[data-theme="dark"] {
    --bg:          #0f172a;
    --card-bg:     #1e293b;
    --input-bg:    #1e293b;
    --text:        #f1f5f9;
    --text-muted:  #94a3b8;
    --border:      #334155;
    --hero-bg:     linear-gradient(135deg, #1e293b 0%, #0f172a 100%);
    --shadow:      0 4px 24px rgba(0, 0, 0, 0.35);
    --shadow-sm:   0 2px 10px rgba(0, 0, 0, 0.25);
    --shadow-hover:0 8px 30px rgba(0, 0, 0, 0.45);
}

/* ----------------------------------------------------------------
   Reset & Base
   ---------------------------------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background: var(--bg);
    color: var(--text);
    transition: background var(--transition), color var(--transition);
    min-height: 100vh;
    font-size: 0.9rem;
    line-height: 1.6;
}

/* ----------------------------------------------------------------
   Header
   ---------------------------------------------------------------- */
.app-header {
    background: var(--header-bg);
    color: white;
    position: sticky;
    top: 0;
    z-index: 200;
    box-shadow: 0 4px 20px rgba(79, 70, 229, 0.35);
}

.brand-icon {
    width: 46px;
    height: 46px;
    min-width: 46px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 21px;
    color: white;
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.app-title {
    font-size: 1.25rem;
    font-weight: 800;
    color: white;
    letter-spacing: -0.3px;
    line-height: 1.2;
}

.app-subtitle {
    font-size: 0.75rem;
    color: rgba(255, 255, 255, 0.82);
    font-weight: 400;
}

.built-by-badge {
    display: inline-flex;
    align-items: center;
    gap: 5px;
    background: rgba(255, 255, 255, 0.18);
    color: white;
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 0.78rem;
    font-weight: 600;
    backdrop-filter: blur(8px);
    border: 1px solid rgba(255, 255, 255, 0.28);
    white-space: nowrap;
    letter-spacing: 0.2px;
}

/* Theme Toggle Button */
.theme-toggle {
    width: 40px;
    height: 40px;
    min-width: 40px;
    background: rgba(255, 255, 255, 0.18);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    font-size: 17px;
    color: white;
    transition: background var(--transition), transform var(--transition);
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.32);
    transform: scale(1.1) rotate(15deg);
}

.theme-toggle:focus-visible {
    outline: 2px solid white;
    outline-offset: 2px;
}

/* ----------------------------------------------------------------
   Hero Banner
   ---------------------------------------------------------------- */
.hero-banner {
    background: var(--hero-bg);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition), border-color var(--transition);
}

.stat-card {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 9px 12px;
    background: var(--card-bg);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-sm);
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text);
    transition: background var(--transition), color var(--transition), box-shadow var(--transition);
    border: 1px solid var(--border);
}

.stat-card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-1px);
}

/* ----------------------------------------------------------------
   Section Cards
   ---------------------------------------------------------------- */
.section-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    transition: background var(--transition), border-color var(--transition), box-shadow var(--transition);
    overflow: hidden;
}

.section-card:hover {
    box-shadow: var(--shadow-hover);
}

.section-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 0;
}

.section-label-sm {
    font-size: 0.72rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-muted);
}

/* ----------------------------------------------------------------
   Mode Toggle (Radio Buttons)
   ---------------------------------------------------------------- */
.mode-toggle-group {
    display: flex;
    gap: 10px;
}

.mode-btn {
    flex: 1;
    padding: 9px 16px;
    border-radius: var(--radius-sm) !important;
    font-weight: 600;
    font-size: 0.85rem;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
}

.btn-check:checked + .mode-btn {
    background: var(--primary);
    border-color: var(--primary);
    color: white;
    box-shadow: 0 4px 14px rgba(79, 70, 229, 0.38);
}

.btn-check:focus + .mode-btn {
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.25);
}

/* ----------------------------------------------------------------
   Form Controls
   ---------------------------------------------------------------- */
.form-control,
.form-select {
    background: var(--input-bg);
    border: 1.5px solid var(--border);
    color: var(--text);
    border-radius: var(--radius-sm);
    font-size: 0.86rem;
    transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
    padding: 8px 12px;
}

.form-control:focus,
.form-select:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.14);
    background: var(--input-bg);
    color: var(--text);
    outline: none;
}

.form-control::placeholder {
    color: var(--text-muted);
    opacity: 0.75;
}

[data-theme="dark"] .form-control,
[data-theme="dark"] .form-select {
    color: var(--text);
    background-color: var(--input-bg);
    border-color: var(--border);
}

[data-theme="dark"] .form-select option {
    background: #1e293b;
    color: var(--text);
}

.input-group-text {
    background: var(--primary-light);
    border: 1.5px solid var(--border);
    border-right: none;
    color: var(--primary);
    font-size: 0.9rem;
    transition: background var(--transition), border-color var(--transition);
}

[data-theme="dark"] .input-group-text {
    background: #2d3748;
    color: #818cf8;
    border-color: var(--border);
}

.form-label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 5px;
    transition: color var(--transition);
}

.form-text.counter-text {
    font-size: 0.75rem;
    color: var(--primary);
    font-weight: 500;
}

/* Validation States */
.form-control.is-invalid,
.form-select.is-invalid {
    border-color: var(--danger);
    box-shadow: 0 0 0 3px rgba(239, 68, 68, 0.12);
}

.invalid-feedback {
    font-size: 0.75rem;
    color: var(--danger);
}

/* ----------------------------------------------------------------
   Generate Button
   ---------------------------------------------------------------- */
.btn-generate {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    border: none;
    color: white;
    padding: 13px 24px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 700;
    letter-spacing: 0.3px;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 4px 16px rgba(79, 70, 229, 0.42);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-generate:hover:not(:disabled) {
    transform: translateY(-2px);
    box-shadow: 0 8px 28px rgba(79, 70, 229, 0.52);
    color: white;
}

.btn-generate:active:not(:disabled) {
    transform: translateY(0);
}

.btn-generate:disabled {
    opacity: 0.75;
    cursor: not-allowed;
}

/* Reset Button */
.btn-reset {
    background: transparent;
    border: 1.5px solid var(--border);
    color: var(--text-muted);
    padding: 10px 24px;
    border-radius: var(--radius-sm);
    font-size: 0.86rem;
    font-weight: 500;
    transition: all var(--transition);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 7px;
}

.btn-reset:hover {
    border-color: var(--danger);
    color: var(--danger);
    background: rgba(239, 68, 68, 0.06);
}

/* ----------------------------------------------------------------
   Message Preview Boxes
   ---------------------------------------------------------------- */
.message-preview {
    background: var(--bg);
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 14px 16px;
    font-size: 0.85rem;
    line-height: 1.75;
    white-space: pre-line;
    color: var(--text);
    min-height: 130px;
    max-height: 280px;
    overflow-y: auto;
    transition: background var(--transition), border-color var(--transition);
    word-break: break-word;
}

.email-subject {
    background: var(--bg);
    border: 1.5px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
    font-size: 0.84rem;
    font-weight: 600;
    color: var(--text);
    transition: background var(--transition), border-color var(--transition);
    word-break: break-word;
}

/* ----------------------------------------------------------------
   Action Buttons (Copy / WhatsApp / Email)
   ---------------------------------------------------------------- */
.btn-copy {
    background: var(--primary-light);
    color: var(--primary);
    border: 1.5px solid var(--primary);
    border-radius: 7px;
    font-weight: 600;
    font-size: 0.8rem;
    padding: 5px 13px;
    transition: all var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-copy:hover {
    background: var(--primary);
    color: white;
}

[data-theme="dark"] .btn-copy {
    background: rgba(79, 70, 229, 0.18);
    color: #818cf8;
    border-color: #4f46e5;
}

[data-theme="dark"] .btn-copy:hover {
    background: var(--primary);
    color: white;
}

.btn-whatsapp {
    background: #25D366;
    color: white;
    border: none;
    border-radius: 7px;
    font-weight: 600;
    font-size: 0.8rem;
    padding: 5px 13px;
    transition: background var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.btn-whatsapp:hover {
    background: #1db954;
    color: white;
}

/* Export Action Buttons */
.btn-action {
    background: var(--card-bg);
    border: 1.5px solid var(--border);
    color: var(--text);
    border-radius: var(--radius-sm);
    padding: 11px 6px;
    font-size: 0.78rem;
    font-weight: 600;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
    transition: all var(--transition);
    cursor: pointer;
}

.btn-action i {
    font-size: 1.35rem;
    color: var(--primary);
    transition: color var(--transition);
}

.btn-action:hover {
    background: var(--primary-light);
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.btn-action:hover i {
    color: var(--primary);
}

[data-theme="dark"] .btn-action {
    background: #2d3748;
    border-color: var(--border);
    color: var(--text);
}

[data-theme="dark"] .btn-action:hover {
    background: rgba(79, 70, 229, 0.22);
    border-color: #4f46e5;
    color: #818cf8;
}

[data-theme="dark"] .btn-action:hover i {
    color: #818cf8;
}

/* ----------------------------------------------------------------
   Card Header / Nav Tabs
   ---------------------------------------------------------------- */
.card-header {
    background: var(--card-bg);
    border-bottom: 1px solid var(--border);
    transition: background var(--transition), border-color var(--transition);
}

.nav-tabs {
    border-bottom: 2px solid var(--border);
    padding: 0 4px;
    gap: 0;
    flex-wrap: nowrap;
    overflow-x: auto;
    scrollbar-width: none;
}

.nav-tabs::-webkit-scrollbar { display: none; }

.nav-tabs .nav-link {
    color: var(--text-muted);
    font-size: 0.82rem;
    font-weight: 600;
    border: none;
    border-bottom: 3px solid transparent;
    padding: 11px 14px;
    transition: all var(--transition);
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 5px;
    background: transparent;
    margin-bottom: -2px;
}

.nav-tabs .nav-link.active {
    color: var(--primary);
    border-bottom-color: var(--primary);
    background: transparent;
}

.nav-tabs .nav-link:hover:not(.active) {
    color: var(--primary);
    border-bottom-color: rgba(79, 70, 229, 0.3);
}

/* ----------------------------------------------------------------
   SMS Counter
   ---------------------------------------------------------------- */
.sms-counter {
    display: inline-block;
    padding: 3px 10px;
    background: var(--bg);
    border-radius: 20px;
    color: var(--text-muted);
    border: 1px solid var(--border);
    font-size: 0.75rem;
}

/* ----------------------------------------------------------------
   Bulk Stats Bar
   ---------------------------------------------------------------- */
.stats-bar {
    background: linear-gradient(135deg, #e0f2fe 0%, #bfdbfe 100%);
    border: 1px solid #bae6fd;
    border-radius: var(--radius-sm);
    padding: 12px 16px;
    color: #1e40af;
    font-size: 0.83rem;
    font-weight: 500;
}

[data-theme="dark"] .stats-bar {
    background: rgba(14, 165, 233, 0.12);
    border-color: rgba(14, 165, 233, 0.25);
    color: #7dd3fc;
}

/* ----------------------------------------------------------------
   Bulk WhatsApp Links Container
   ---------------------------------------------------------------- */
.bulk-links-container {
    display: flex;
    flex-direction: column;
    gap: 6px;
    max-height: 220px;
    overflow-y: auto;
    padding: 10px;
    background: var(--bg);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
}

.bulk-link-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    padding: 7px 12px;
    background: var(--card-bg);
    border-radius: 7px;
    font-size: 0.8rem;
    border: 1px solid var(--border);
    transition: background var(--transition);
}

.bulk-link-item:hover {
    background: var(--primary-light);
    border-color: rgba(79, 70, 229, 0.3);
}

[data-theme="dark"] .bulk-link-item:hover {
    background: rgba(79, 70, 229, 0.15);
}

.bulk-link-item a {
    color: #1da851;
    text-decoration: none;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 4px;
    white-space: nowrap;
}

.bulk-link-item a:hover {
    text-decoration: underline;
}

.bulk-link-item .phone-label {
    color: var(--text);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

/* ----------------------------------------------------------------
   Empty State
   ---------------------------------------------------------------- */
.empty-state-card {
    background: var(--card-bg);
    border: 2px dashed var(--border);
    border-radius: var(--radius);
    padding: 52px 28px;
    text-align: center;
    color: var(--text);
    min-height: 420px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 10px;
    transition: background var(--transition), border-color var(--transition);
}

.empty-state-icon {
    width: 78px;
    height: 78px;
    background: var(--primary-light);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 34px;
    color: var(--primary);
    margin-bottom: 6px;
}

[data-theme="dark"] .empty-state-icon {
    background: rgba(79, 70, 229, 0.2);
    color: #818cf8;
}

.fw-700 { font-weight: 700; }

.feature-pills {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    justify-content: center;
    margin-top: 8px;
}

.pill {
    background: var(--bg);
    border: 1.5px solid var(--border);
    color: var(--text);
    padding: 5px 14px;
    border-radius: 20px;
    font-size: 0.78rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    gap: 5px;
    transition: all var(--transition);
}

.pill:hover {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}

/* ----------------------------------------------------------------
   Footer
   ---------------------------------------------------------------- */
.app-footer {
    background: var(--card-bg);
    border-top: 1px solid var(--border);
    color: var(--text);
    font-size: 0.86rem;
    transition: background var(--transition), border-color var(--transition);
}

/* ----------------------------------------------------------------
   Toast
   ---------------------------------------------------------------- */
.toast {
    border-radius: 10px;
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.28);
    min-width: 260px;
}

.toast-body {
    font-size: 0.85rem;
    font-weight: 600;
    color: white;
    padding: 12px 16px;
}

/* ----------------------------------------------------------------
   Custom Scrollbar
   ---------------------------------------------------------------- */
::-webkit-scrollbar { width: 5px; height: 5px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--primary); border-radius: 10px; }
::-webkit-scrollbar-thumb:hover { background: var(--primary-dark); }

/* ----------------------------------------------------------------
   Animations
   ---------------------------------------------------------------- */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(22px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes scaleIn {
    from { opacity: 0; transform: scale(0.96); }
    to   { opacity: 1; transform: scale(1); }
}

.animate-in {
    animation: fadeInUp 0.38s ease forwards;
}

.animate-scale {
    animation: scaleIn 0.28s ease forwards;
}

/* ----------------------------------------------------------------
   Responsive – Tablet & Mobile
   ---------------------------------------------------------------- */
@media (max-width: 991.98px) {
    .empty-state-card {
        min-height: 280px;
        padding: 36px 20px;
    }
}

@media (max-width: 767.98px) {
    .app-title {
        font-size: 1.05rem;
    }

    .app-subtitle {
        display: none;
    }

    .brand-icon {
        width: 38px;
        height: 38px;
        min-width: 38px;
        font-size: 17px;
    }

    .nav-tabs .nav-link {
        padding: 9px 10px;
        font-size: 0.78rem;
    }

    .btn-action {
        padding: 10px 4px;
    }
}

@media (max-width: 575.98px) {
    .mode-btn {
        font-size: 0.8rem;
        padding: 8px 10px;
    }

    .stat-card {
        font-size: 0.75rem;
        padding: 8px;
    }

    .stat-card span {
        display: none;
    }
}

/* ================================================================
   Bulk Mode v2 – Generalized / Personalized Components
   ================================================================ */

/* ----------------------------------------------------------------
   Bulk sub-mode helper text banner
   ---------------------------------------------------------------- */
.bulk-helper-text {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    background: rgba(14, 165, 233, 0.09);
    border: 1px solid rgba(14, 165, 233, 0.25);
    border-radius: var(--radius-sm);
    padding: 10px 14px;
    font-size: 0.82rem;
    color: var(--text);
    line-height: 1.5;
}
.bulk-helper-text i { color: #0ea5e9; flex-shrink: 0; margin-top: 1px; }
[data-theme="dark"] .bulk-helper-text {
    background: rgba(14, 165, 233, 0.12);
    border-color: rgba(14, 165, 233, 0.3);
}