/**
 * KTU CGPA Calculator - Mobile-First PWA Stylesheet
 * Ergonomic, Responsive, Touch-Optimized Design System
 */

:root {
    --bg-body: #F8FAFC;
    --bg-card: #FFFFFF;
    
    --text-main: #0F172A;
    --text-secondary: #475569;
    --text-muted: #94A3B8;
    
    --border-light: #E2E8F0;
    --border-hover: #CBD5E1;
    
    --primary: #0F172A;
    --primary-hover: #1E293B;
    
    --brand-emerald: #059669;
    --brand-emerald-dark: #064E3B;
    --brand-emerald-light: #10B981;
    --brand-emerald-bg: #ECFDF5;

    /* Semantic Grade Colors */
    --grade-s-bg: #DCFCE7;  --grade-s-txt: #166534;
    --grade-ap-bg: #D1FAE5; --grade-ap-txt: #065F46;
    --grade-a-bg: #E0F2FE;  --grade-a-txt: #075985;
    --grade-bp-bg: #FEF3C7; --grade-bp-txt: #92400E;
    --grade-b-bg: #FFEDD5;  --grade-b-txt: #9A3412;
    --grade-c-bg: #F1F5F9;  --grade-c-txt: #334155;
    --grade-f-bg: #FEE2E2;  --grade-f-txt: #991B1B;

    --radius-xl: 20px;
    --radius-lg: 14px;
    --radius-md: 10px;
    --radius-sm: 6px;
    
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -1px rgba(0, 0, 0, 0.03);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.06), 0 8px 10px -6px rgba(0, 0, 0, 0.02);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

body {
    background: var(--bg-body);
    font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-main);
    line-height: 1.5;
    min-height: 100vh;
    padding: env(safe-area-inset-top, 16px) clamp(16px, 2.5vw, 44px) env(safe-area-inset-bottom, 32px) clamp(16px, 2.5vw, 44px);
    width: 100%;
    max-width: min(95vw, 1720px);
    margin: 0 auto;
    -webkit-font-smoothing: antialiased;
}

/* App Header & Navigation Bar */
.app-header {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 14px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: var(--shadow-sm);
    margin-bottom: 16px;
    transition: all 0.2s ease;
}

.brand-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-icon {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    object-fit: cover;
    box-shadow: var(--shadow-sm);
}

.brand-title {
    font-size: 17px;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-main);
}

.brand-badge {
    font-size: 11px;
    font-weight: 600;
    color: var(--brand-emerald);
    background: var(--brand-emerald-bg);
    padding: 2px 9px;
    border-radius: 999px;
    display: inline-block;
}

.version-badge {
    font-size: 10px;
    font-weight: 700;
    font-family: var(--font-mono, monospace);
    color: var(--brand-emerald);
    background: rgba(16, 185, 129, 0.12);
    border: 1px solid rgba(16, 185, 129, 0.25);
    padding: 1.5px 6px;
    border-radius: 6px;
    margin-left: 6px;
    letter-spacing: 0.02em;
    vertical-align: middle;
    display: inline-block;
}

.app-footer {
    margin-top: 36px;
    padding: 20px 0 28px;
    text-align: center;
    border-top: 1px solid var(--border-light);
    color: var(--text-muted);
    font-size: 11.5px;
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    flex-wrap: wrap;
}

.footer-dot {
    opacity: 0.4;
}

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

.icon-btn {
    background: #F1F5F9;
    border: 1px solid var(--border-light);
    color: var(--text-secondary);
    width: 40px;
    height: 40px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 16px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.icon-btn:hover, .icon-btn:active {
    background: #E2E8F0;
    color: var(--text-main);
    transform: translateY(-1px);
}

/* Header Menu Action Buttons (PDF Transcript & Export CSV on Menu) */
.header-menu-btn {
    display: inline-flex;
    align-items: center;
    gap: 7px;
    padding: 8px 14px;
    border-radius: var(--radius-md);
    font-size: 13.5px;
    font-weight: 600;
    cursor: pointer;
    border: 1px solid transparent;
    height: 40px;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    white-space: nowrap;
}

.header-menu-btn.primary {
    background: var(--primary);
    color: #FFFFFF;
    box-shadow: var(--shadow-sm);
}

.header-menu-btn.primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.header-menu-btn.primary:active {
    transform: scale(0.97);
}

.header-menu-btn.secondary {
    background: #FFFFFF;
    border-color: var(--border-light);
    color: var(--text-main);
    box-shadow: var(--shadow-sm);
}

.header-menu-btn.secondary:hover {
    background: #F8FAFC;
    border-color: var(--border-hover);
    transform: translateY(-1px);
}

.header-menu-btn.secondary:active {
    transform: scale(0.97);
}

.header-menu-divider {
    width: 1px;
    height: 24px;
    background: var(--border-light);
    margin: 0 4px;
}

/* Top Dashboard Grid (Responsive: Mobile Stack, Desktop/4K Dual Panel) */
.top-dashboard-grid {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 16px;
}

/* Primary Fast-Sync Hero Box */
.hero-sync-box {
    background: linear-gradient(135deg, #064E3B 0%, #047857 100%);
    border-radius: var(--radius-xl);
    padding: 20px 22px;
    color: #FFFFFF;
    box-shadow: 0 10px 25px -5px rgba(5, 150, 105, 0.35);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.hero-sync-box::after {
    content: "";
    position: absolute;
    top: -50%;
    right: -20%;
    width: 260px;
    height: 260px;
    background: radial-gradient(circle, rgba(52, 211, 153, 0.2) 0%, transparent 70%);
    pointer-events: none;
}

.hero-top-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 12px;
}

.hero-active-profile {
    font-size: 13.5px;
    font-weight: 600;
    color: #A7F3D0;
    display: flex;
    align-items: center;
    gap: 6px;
}

.hero-freshness {
    font-size: 11px;
    background: rgba(0, 0, 0, 0.25);
    backdrop-filter: blur(4px);
    padding: 3px 10px;
    border-radius: 999px;
    color: #E2E8F0;
    font-weight: 500;
}

.hero-btn-row {
    display: flex;
    gap: 12px;
    width: 100%;
}

.btn-fast-sync-main {
    flex: 1.2;
    background: #10B981;
    color: #FFFFFF;
    border: none;
    border-radius: var(--radius-md);
    padding: 14px 18px;
    font-size: 15px;
    font-weight: 700;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    box-shadow: 0 4px 14px rgba(16, 185, 129, 0.4);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    min-height: 52px;
}

.btn-fast-sync-main:hover {
    background: #059669;
    box-shadow: 0 6px 20px rgba(16, 185, 129, 0.5);
    transform: translateY(-1px);
}

.btn-fast-sync-main:active {
    transform: scale(0.98);
}

.btn-fast-sync-refresh {
    flex: 1;
    background: rgba(255, 255, 255, 0.12);
    color: #FFFFFF;
    border: 1px solid rgba(255, 255, 255, 0.25);
    border-radius: var(--radius-md);
    padding: 14px 16px;
    font-size: 14.5px;
    font-weight: 600;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    min-height: 52px;
}

.btn-fast-sync-refresh:hover {
    background: rgba(255, 255, 255, 0.22);
    border-color: rgba(255, 255, 255, 0.4);
    transform: translateY(-1px);
}

.btn-fast-sync-refresh:active {
    transform: scale(0.98);
}

.hero-subtext {
    font-size: 12px;
    color: #D1FAE5;
    text-align: center;
    margin-top: 10px;
    font-weight: 500;
}

/* Student Profile Card */
.profile-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: all 0.2s ease;
}

.profile-card-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
}

.profile-name {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
    letter-spacing: -0.01em;
}

.profile-regno {
    font-family: "JetBrains Mono", monospace;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--text-secondary);
    background: #F1F5F9;
    padding: 3px 10px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-light);
}

.profile-institution {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 6px;
}

.profile-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
}

.pill-badge {
    font-size: 11.5px;
    font-weight: 600;
    background: #F1F5F9;
    color: var(--text-secondary);
    border: 1px solid var(--border-light);
    padding: 3px 10px;
    border-radius: 999px;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.pill-badge.active-scheme {
    background: #EFF6FF;
    color: #1D4ED8;
    border-color: #BFDBFE;
}

/* Degree Forecast Active Banner */
.forecast-banner {
    background: #EFF6FF;
    border: 1px solid #BFDBFE;
    border-radius: var(--radius-xl);
    padding: 16px 20px;
    margin-bottom: 16px;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    justify-content: space-between;
    transition: all 0.2s ease;
}

/* Level 1 Completed Degree Notice in Modal */
.forecast-level-notice {
    background: #FEF3C7;
    border: 1px solid #FCD34D;
    color: #92400E;
    border-radius: var(--radius-md);
    padding: 10px 14px;
    font-size: 12px;
    line-height: 1.45;
    margin-bottom: 14px;
}

/* Stats Overview Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 16px;
}

.stat-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    padding: 16px 14px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    position: relative;
    cursor: default;
    transition: all 0.2s ease;
}

.stat-card.featured {
    grid-column: span 2;
    background: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
    border: 1.5px solid #059669;
    padding: 22px 16px;
    cursor: pointer;
    box-shadow: 0 4px 12px -2px rgba(5, 150, 105, 0.12);
}

.stat-card .value {
    font-size: clamp(26px, 2.2vw, 36px);
    font-weight: 800;
    line-height: 1.1;
    font-family: "JetBrains Mono", monospace;
    color: var(--text-main);
    letter-spacing: -0.03em;
}

.stat-card.featured .value {
    font-size: clamp(38px, 3.2vw, 54px);
    color: #059669;
}

.stat-card .label {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 600;
    margin-top: 5px;
}

.stat-card.accent-success {
    border-color: #A7F3D0;
    background: #F0FDF4;
}
.stat-card.accent-success .value { color: #166534; }

.stat-card.accent-danger {
    border-color: #FECACA;
    background: #FEF2F2;
}
.stat-card.accent-danger .value { color: #991B1B; }

.stat-progress-bar {
    width: 100%;
    height: 6px;
    background: #E2E8F0;
    border-radius: 999px;
    margin-top: 8px;
    overflow: hidden;
}

.stat-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #059669, #10B981);
    border-radius: 999px;
    transition: width 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Copy Toast */
.copy-toast {
    position: absolute;
    top: 8px;
    right: 12px;
    background: #059669;
    color: #FFFFFF;
    font-size: 10.5px;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 999px;
    opacity: 0;
    transition: opacity 0.2s ease;
    pointer-events: none;
}
.copy-toast.show { opacity: 1; }

/* Section Headers */
.section-header {
    grid-column: 1 / -1;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin: 20px 0 12px 0;
}

.section-title {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

/* Academic Comeback & Future Degree Projections Grid */
.comeback-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-bottom: 16px;
}

.comeback-grid .stat-card {
    padding: 12px 6px;
    text-align: center;
    border-radius: var(--radius-md);
}

.comeback-grid .stat-card .value {
    font-size: 17px;
    font-weight: 800;
    font-family: "JetBrains Mono", monospace;
    letter-spacing: -0.02em;
}

.comeback-grid .stat-card .label {
    font-size: 11px;
    font-weight: 600;
    margin-top: 4px;
    color: var(--text-secondary);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.featured-comeback-card {
    grid-column: 1 / -1 !important;
    padding: 16px 14px !important;
    background: linear-gradient(180deg, #F0FDF4 0%, #DCFCE7 100%) !important;
    border: 1.5px solid #10B981 !important;
}

.featured-comeback-card .value {
    font-size: clamp(24px, 2.2vw, 32px) !important;
    color: #065F46 !important;
}

.featured-comeback-card .label {
    font-size: 12.5px !important;
    color: #047857 !important;
    white-space: normal !important;
}

/* Semester Breakdown Cards (Mobile Accordion / Desktop Multi-Column Grid) */
#semesterContainer {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.semester-card {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
    transition: all 0.2s ease;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.semester-card.projected {
    border-style: dashed;
    border-color: #93C5FD;
}

.semester-header {
    padding: 14px 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: pointer;
    user-select: none;
    background: #FFFFFF;
    transition: background 0.15s ease;
}

.semester-header:hover {
    background: #F8FAFC;
}

.semester-title {
    font-size: 15px;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.accordion-chevron {
    font-size: 12px;
    color: var(--text-muted);
    transition: transform 0.2s ease;
}

.semester-card.collapsed .accordion-chevron {
    transform: rotate(-90deg);
}

.semester-card.collapsed .semester-body {
    display: none;
}

.semester-sgpa-badge {
    font-size: 13.5px;
    font-weight: 700;
    font-family: "JetBrains Mono", monospace;
    color: var(--text-secondary);
}

.semester-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 0 18px 12px 18px;
    background: #FFFFFF;
}

.semester-body {
    border-top: 1px solid #F1F5F9;
    flex: 1;
    display: flex;
    flex-direction: column;
    max-height: none;
    overflow: visible;
}

/* Checkerboard Highlighting for Subject Rows: Minimal grey shade to distinguish for eyes perfectly */
.subject-row {
    padding: 10px 18px;
    border-bottom: 1px solid rgba(226, 232, 240, 0.65);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-size: 13px;
    transition: background 0.15s ease;
}

.subject-row:nth-child(odd) {
    background: #FFFFFF;
}

.subject-row:nth-child(even) {
    background: #F8FAFC; /* Minimal subtle grey (Slate 50) */
}

.subject-row:hover {
    background: #EEF2F6; /* Clear interactive focus */
}

.subject-row:last-child {
    border-bottom: none;
}

.subject-info {
    max-width: 76%;
}

.subject-code {
    font-family: "JetBrains Mono", monospace;
    font-size: 11px;
    color: var(--text-muted);
    font-weight: 600;
}

.subject-name {
    font-weight: 500;
    color: var(--text-main);
    line-height: 1.35;
}

.subject-right {
    display: flex;
    align-items: center;
    gap: 8px;
}

.subject-credit {
    font-size: 11.5px;
    font-family: "JetBrains Mono", monospace;
    color: var(--text-muted);
}

/* Grade Badges */
.grade-badge {
    font-family: "JetBrains Mono", monospace;
    font-size: 12px;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: var(--radius-sm);
    min-width: 32px;
    text-align: center;
}

.grade-S, .grade-O { background: var(--grade-s-bg); color: var(--grade-s-txt); }
.grade-Aplus { background: var(--grade-ap-bg); color: var(--grade-ap-txt); }
.grade-A { background: var(--grade-a-bg); color: var(--grade-a-txt); }
.grade-Bplus { background: var(--grade-bp-bg); color: var(--grade-bp-txt); }
.grade-B { background: var(--grade-b-bg); color: var(--grade-b-txt); }
.grade-C { background: var(--grade-c-bg); color: var(--grade-c-txt); }
.grade-F { background: var(--grade-f-bg); color: var(--grade-f-txt); }
.grade-planned { background: #EFF6FF; color: #1E40AF; border: 1px dashed #93C5FD; }

/* Bottom Action Bar */
.bottom-actions {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-top: 24px;
    margin-bottom: 24px;
}

.btn-action {
    padding: 13px 18px;
    font-size: 14.5px;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    border: 1px solid transparent;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    min-height: 48px;
}

.btn-action.primary {
    background: var(--primary);
    color: #FFFFFF;
    box-shadow: var(--shadow-sm);
}
.btn-action.primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}
.btn-action.primary:active { transform: scale(0.98); }

.btn-action.secondary {
    background: var(--bg-card);
    border-color: var(--border-light);
    color: var(--text-main);
    box-shadow: var(--shadow-sm);
}
.btn-action.secondary:hover {
    background: #F1F5F9;
    border-color: var(--border-hover);
    transform: translateY(-1px);
}
.btn-action.secondary:active { transform: scale(0.98); }

/* Modal Bottom Sheets & Centered Dialogs */
.modal-overlay {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(15, 23, 42, 0.6);
    backdrop-filter: blur(5px);
    z-index: 9999;
    display: none;
    align-items: flex-end;
    justify-content: center;
}

.modal-sheet {
    background: #FFFFFF;
    width: 100%;
    max-width: 580px;
    border-radius: 24px 24px 0 0;
    padding: 24px 22px 32px 22px;
    max-height: 85vh;
    overflow-y: auto;
    box-shadow: 0 -10px 30px rgba(0, 0, 0, 0.15);
    animation: slideUp 0.25s ease-out;
}

@keyframes slideUp {
    from { transform: translateY(100%); }
    to { transform: translateY(0); }
}

@keyframes scaleUp {
    from { transform: scale(0.95); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.sheet-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-light);
}

.sheet-title {
    font-size: 17px;
    font-weight: 700;
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 8px;
}

.sheet-close-btn {
    background: #F1F5F9;
    border: none;
    font-size: 16px;
    width: 34px;
    height: 34px;
    border-radius: 999px;
    cursor: pointer;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s ease;
}

.sheet-close-btn:hover {
    background: #E2E8F0;
    color: var(--text-main);
}

/* Forms in Modal */
.form-group {
    margin-bottom: 14px;
}

.form-group label {
    display: block;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 6px;
}

.form-control {
    width: 100%;
    padding: 12px 14px;
    font-size: 14px;
    border: 1px solid var(--border-light);
    border-radius: var(--radius-md);
    background: #F8FAFC;
    color: var(--text-main);
    outline: none;
    transition: border-color 0.15s ease, background 0.15s ease;
}

.form-control:focus {
    border-color: #059669;
    background: #FFFFFF;
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.1);
}

/* Status Toasts */
.status-pill {
    padding: 11px 16px;
    border-radius: var(--radius-md);
    font-size: 13.5px;
    margin-top: 12px;
    display: none;
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

.status-pill.loading { background: #EFF6FF; color: #1D4ED8; border: 1px solid #BFDBFE; }
.status-pill.success { background: #ECFDF5; color: #047857; border: 1px solid #A7F3D0; }
.status-pill.error { background: #FEF2F2; color: #991B1B; border: 1px solid #FECACA; }
.status-pill.warning { background: #FFFBEB; color: #B45309; border: 1px solid #FDE68A; }

/* Empty State */
.empty-state {
    background: var(--bg-card);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-xl);
    padding: 40px 24px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    margin-bottom: 16px;
}

.empty-icon { font-size: 48px; margin-bottom: 12px; }
.empty-title { font-size: 19px; font-weight: 700; margin-bottom: 6px; }
.empty-desc { font-size: 13.5px; color: var(--text-secondary); margin-bottom: 20px; line-height: 1.5; }

@media (max-width: 767px) {
    .stats-grid > .stat-card:nth-child(4) {
        grid-column: span 2;
    }
}

@media (max-width: 480px) {
    .hero-btn-row {
        flex-direction: column;
        gap: 8px;
    }
    .btn-fast-sync-main,
    .btn-fast-sync-refresh {
        width: 100%;
        min-height: 48px;
        font-size: 14px;
        padding: 12px 14px;
    }
}

@media (max-width: 400px) {
    .brand-title {
        font-size: 15px;
    }
    .brand-badge {
        display: none;
    }
    .hero-sync-box {
        padding: 16px 16px;
    }
    .stat-card {
        padding: 12px 10px;
    }
    .stat-card .value {
        font-size: 22px;
    }
    .stat-card.featured .value {
        font-size: 34px;
    }
}

/* ========================================================================== */
/* RESPONSIVE BREAKPOINTS: Tablet, Laptop, Desktop & 4K Displays              */
/* ========================================================================== */

/* 1. MOBILE & TABLET COMMON ICON RULES (max-width: 1023px) */
@media (max-width: 1023px) {
    .header-menu-btn,
    .header-menu-divider {
        display: none !important;
    }

    /* On mobile & tablet, bottom action bar transforms into two sleek compact icon buttons */
    .bottom-actions {
        display: flex !important;
        justify-content: center;
        align-items: center;
        gap: 16px;
        margin-top: 22px;
        margin-bottom: 24px;
    }
    .bottom-actions .btn-action.icon-action-btn {
        flex: 0 0 auto;
        width: 54px;
        height: 54px;
        min-height: 54px;
        min-width: 54px;
        padding: 0;
        border-radius: 16px;
        display: flex;
        align-items: center;
        justify-content: center;
        box-shadow: var(--shadow-md);
    }
    .bottom-actions .btn-action.icon-action-btn .btn-icon {
        font-size: 24px;
    }
    .bottom-actions .btn-action.icon-action-btn .action-btn-text {
        display: none;
    }
}

/* 2. TABLET & SMALL LAPTOPS (min-width: 768px) */
@media (min-width: 768px) {
    .modal-overlay {
        align-items: center;
        justify-content: center;
        padding: 24px;
    }

    .modal-sheet {
        border-radius: var(--radius-xl);
        max-width: 540px;
        box-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.25);
        animation: scaleUp 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    }

    /* Keep Fast Sync and Student Profile Card side-by-side with matched heights */
    .top-dashboard-grid {
        display: grid !important;
        grid-template-columns: 1fr 1fr !important;
        gap: 16px;
        align-items: stretch;
    }

    .top-dashboard-grid .hero-sync-box,
    .top-dashboard-grid #profileCard {
        height: 100% !important;
        margin-bottom: 0 !important;
        display: flex !important;
        flex-direction: column !important;
        justify-content: space-between !important;
    }

    .stats-grid {
        grid-template-columns: 1.4fr 1fr 1fr 1.1fr !important;
        gap: 14px;
    }

    .stat-card.featured {
        grid-column: 1 / 2 !important;
    }

    /* 2-Column Semester Layout for Tablets */
    #semesterContainer {
        display: grid;
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
        align-items: stretch;
    }

    .semester-card {
        margin-bottom: 0;
    }
}

/* 3. LAPTOP & PC DESKTOP (min-width: 1024px) */
@media (min-width: 1024px) {
    /* Side-by-side companion panels (50% / 50%) */
    .top-dashboard-grid {
        display: grid !important;
        grid-template-columns: 1fr 1fr !important;
        gap: 20px !important;
        align-items: stretch !important;
        margin-bottom: 20px;
    }

    .top-dashboard-grid .hero-sync-box,
    .top-dashboard-grid #profileCard {
        height: 100% !important;
        margin-bottom: 0 !important;
        display: flex !important;
        flex-direction: column !important;
        justify-content: space-between !important;
    }

    .stats-grid {
        grid-template-columns: 1.5fr 1fr 1fr 1.15fr !important;
        gap: 16px;
        margin-bottom: 20px;
    }

    #semesterContainer {
        gap: 18px;
    }

    /* Academic Comeback Projections: 8 target columns on PC in single row */
    .comeback-grid {
        grid-template-columns: repeat(8, 1fr) !important;
        gap: 12px;
    }

    /* PDF and CSV are in Header Menu, hide redundant bottom bar on PC */
    #bottomActionBar {
        display: none !important;
    }

    /* Subtle hover elevation on pointer devices */
    .stat-card:hover {
        transform: translateY(-2px);
        box-shadow: var(--shadow-md);
        border-color: var(--border-hover);
    }

    .semester-card:hover {
        border-color: #CBD5E1;
        box-shadow: var(--shadow-md);
    }
}

/* 4. ULTRA-WIDE & 4K MONITORS (min-width: 1540px, 27" QHD & 32"+ 4K UHD) */
@media (min-width: 1540px) {
    /* 4-Column Semester Grid: Row 1 = S1–S4, Row 2 = S5–S8 */
    #semesterContainer {
        grid-template-columns: repeat(4, 1fr) !important;
        gap: 20px;
    }

    .top-dashboard-grid {
        display: grid !important;
        grid-template-columns: 1fr 1fr !important;
        gap: 24px !important;
    }

    .top-dashboard-grid .hero-sync-box,
    .top-dashboard-grid #profileCard {
        height: 100% !important;
        margin-bottom: 0 !important;
    }

    .comeback-grid {
        grid-template-columns: repeat(8, 1fr) !important;
        gap: 16px;
    }

    .app-header {
        padding: 16px 26px;
        margin-bottom: 20px;
    }

    .brand-title {
        font-size: 19px;
    }

    .brand-icon {
        width: 44px;
        height: 44px;
    }

    .hero-sync-box {
        padding: 24px 28px;
    }

    .profile-card {
        padding: 24px 26px;
    }

    .profile-name {
        font-size: 19px;
    }

    .stats-grid {
        gap: 20px;
        margin-bottom: 24px;
    }

    .stat-card {
        padding: 22px 20px;
    }

    .semester-header {
        padding: 16px 20px;
    }

    .semester-title {
        font-size: 16px;
    }

    .subject-row {
        padding: 12px 20px;
        font-size: 13.5px;
    }
}

/* 4. EXTREME 4K & ULTRA-WIDE RESOLUTION (min-width: 2560px) */
@media (min-width: 2560px) {
    body {
        max-width: min(94vw, 2560px);
        padding: clamp(24px, 2vw, 44px) clamp(32px, 3vw, 64px);
    }

    .app-header {
        padding: 20px 32px;
        border-radius: 20px;
        margin-bottom: 24px;
    }

    .brand-title {
        font-size: 24px;
    }

    .brand-icon {
        width: 50px;
        height: 50px;
        border-radius: 12px;
    }

    .icon-btn {
        width: 48px;
        height: 48px;
        font-size: 20px;
        border-radius: 12px;
    }

    .top-dashboard-grid {
        gap: 28px;
        margin-bottom: 28px;
    }

    .hero-sync-box {
        padding: 28px 34px;
        border-radius: 24px;
    }

    .hero-active-profile {
        font-size: 16px;
    }

    .btn-fast-sync-main {
        font-size: 19px;
        min-height: 62px;
        border-radius: 14px;
    }

    .btn-fast-sync-refresh {
        font-size: 17px;
        min-height: 62px;
        border-radius: 14px;
    }

    .hero-subtext {
        font-size: 14px;
        margin-top: 14px;
    }

    .profile-card {
        padding: 28px 32px;
        border-radius: 24px;
    }

    .profile-name {
        font-size: 22px;
    }

    .profile-regno {
        font-size: 14px;
        padding: 4px 12px;
    }

    .profile-institution {
        font-size: 15px;
        margin-bottom: 16px;
    }

    .pill-badge {
        font-size: 13px;
        padding: 5px 14px;
    }

    .stats-grid {
        gap: 24px;
        margin-bottom: 28px;
    }

    .stat-card {
        padding: 26px 24px;
        border-radius: 20px;
    }

    .stat-card.featured .value {
        font-size: 64px;
    }

    .stat-card .value {
        font-size: 38px;
    }

    .stat-card .label {
        font-size: 14.5px;
        margin-top: 8px;
    }

    .section-title {
        font-size: 20px;
        margin: 28px 0 16px 0;
    }

    #semesterContainer {
        gap: 24px;
    }

    .semester-card {
        border-radius: 20px;
    }

    .semester-header {
        padding: 18px 24px;
    }

    .semester-title {
        font-size: 18px;
    }

    .semester-sgpa-badge {
        font-size: 16px;
    }

    .subject-row {
        padding: 14px 24px;
        font-size: 15px;
    }

    .subject-code {
        font-size: 12.5px;
    }

    .grade-badge {
        font-size: 14px;
        padding: 4px 12px;
    }

    .modal-sheet {
        max-width: 660px;
        padding: 32px 36px;
        border-radius: 28px;
    }

    .sheet-title {
        font-size: 20px;
    }

    .form-group label {
        font-size: 14.5px;
    }

    .form-control {
        font-size: 16px;
        padding: 14px 18px;
        border-radius: 12px;
    }
}



/* Quick Switcher Dropdown in Header */
.header-profile-select {
    padding: 6px 10px;
    font-size: 12px;
    font-weight: 600;
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.85);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-sm);
    cursor: pointer;
    outline: none;
    max-width: 170px;
    transition: all var(--transition-fast);
}
.header-profile-select:hover {
    border-color: var(--primary);
    background: #FFFFFF;
}
@media (max-width: 640px) {
    .header-profile-select {
        max-width: 120px;
        font-size: 11px;
        padding: 4px 6px;
    }
}