/*
 * G.C.E. A/L Combined Mathematics Progress Tracker
 * Premium Redesigned Vanilla CSS Stylesheet
 * Fully Responsive, Glassmorphic UI with High Contrast & Micro-animations
 */

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+Sinhala:wght@300;400;500;600;700&family=Outfit:wght@300;400;500;600;700&display=swap');

/* CSS Variables for Dark and Light Themes */
:root {
    /* Base Backgrounds */
    --bg-primary: #070a13;
    --bg-secondary: #0f1524;
    --bg-sidebar: rgba(15, 21, 36, 0.8);
    
    /* Card Settings */
    --card-bg: rgba(20, 27, 47, 0.6);
    --card-border: rgba(255, 255, 255, 0.12);
    --card-border-active: rgba(99, 102, 241, 0.4);
    
    /* Typography colors (High Contrast) */
    --text-primary: #ffffff;
    --text-secondary: #cbd5e1;
    --text-muted: #94a3b8;
    
    /* Elegant Accents */
    --accent-indigo: #6366f1;
    --accent-indigo-glow: rgba(99, 102, 241, 0.35);
    --accent-cyan: #06b6d4;
    --accent-cyan-glow: rgba(6, 182, 212, 0.3);
    --accent-emerald: #10b981;
    --accent-emerald-glow: rgba(16, 185, 129, 0.3);
    --accent-orange: #f97316;
    --accent-orange-glow: rgba(249, 115, 22, 0.25);
    --accent-rose: #ef4444;
    
    /* Shadows, Blurs & Animations */
    --shadow-premium: 0 15px 35px -10px rgba(0, 0, 0, 0.6), 0 5px 15px -5px rgba(0, 0, 0, 0.4);
    --glass-blur: blur(16px);
    --transition-smooth: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    
    --font-si: 'Noto Sans Sinhala', sans-serif;
    --font-en: 'Outfit', sans-serif;
}

body.light-theme {
    /* Base Backgrounds */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-sidebar: rgba(255, 255, 255, 0.85);
    
    /* Card Settings */
    --card-bg: rgba(255, 255, 255, 0.8);
    --card-border: rgba(15, 23, 42, 0.15);
    --card-border-active: rgba(99, 102, 241, 0.6);
    
    /* Typography colors (High Contrast) */
    --text-primary: #0f172a;
    --text-secondary: #334155;
    --text-muted: #64748b;
    
    /* Accent adjustments for Light Mode readability */
    --accent-indigo: #4f46e5;
    --accent-indigo-glow: rgba(79, 70, 229, 0.15);
    --accent-cyan: #0891b2;
    --accent-cyan-glow: rgba(8, 145, 178, 0.15);
    --accent-emerald: #059669;
    --accent-emerald-glow: rgba(5, 150, 105, 0.15);
    
    --shadow-premium: 0 15px 30px -10px rgba(15, 23, 42, 0.08), 0 4px 12px -4px rgba(15, 23, 42, 0.04);
    --glass-blur: blur(12px);
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: rgba(99, 102, 241, 0.25);
    border: 2.5px solid var(--bg-primary);
    border-radius: 5px;
    transition: var(--transition-smooth);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--accent-indigo);
}

html {
    scroll-behavior: smooth;
}

/* Global resets */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: var(--bg-primary);
    background-image: radial-gradient(at 0% 0%, var(--accent-indigo-glow) 0, transparent 40%),
                      radial-gradient(at 100% 100%, var(--accent-cyan-glow) 0, transparent 40%);
    background-attachment: fixed;
    color: var(--text-primary);
    font-family: var(--font-en);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    transition: background-color 0.4s ease, color 0.4s ease;
}

.sinhala-text {
    font-family: var(--font-si);
    line-height: 1.6;
}

.english-text {
    font-family: var(--font-en);
}

/* Dashboard App Layout Shell */
.app-container {
    max-width: 1440px;
    margin: 0 auto;
    width: 100%;
    padding: 2rem;
    display: grid;
    grid-template-columns: 300px 1fr;
    gap: 2rem;
    flex-grow: 1;
}

/* ============================================================
   Floating Sidebar Navigation
   ============================================================ */
.sidebar {
    background: var(--bg-sidebar);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 2rem 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 2rem;
    height: calc(100vh - 4rem);
    box-shadow: var(--shadow-premium);
    position: sticky;
    top: 2rem;
    z-index: 100;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    overflow-y: auto;
    overflow-x: hidden;
    align-self: start;
    overscroll-behavior: contain;
    scrollbar-width: thin;
    scrollbar-color: rgba(255, 255, 255, 0.15) transparent;
    scroll-behavior: smooth;
}

body.light-theme .sidebar {
    scrollbar-color: rgba(15, 23, 42, 0.15) transparent;
}

/* Sidebar Custom Scrollbars for WebKit (Chrome, Edge, Safari) */
.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.15);
    border-radius: 10px;
    transition: var(--transition-smooth);
}

.sidebar:hover::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.35);
}

body.light-theme .sidebar::-webkit-scrollbar-thumb {
    background: rgba(15, 23, 42, 0.15);
}

body.light-theme .sidebar:hover::-webkit-scrollbar-thumb {
    background: rgba(15, 23, 42, 0.35);
}


.brand-section {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--card-border);
}

.brand-logo {
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
    width: 48px;
    height: 48px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 1.4rem;
    box-shadow: 0 8px 20px var(--accent-indigo-glow);
}

.brand-title {
    display: flex;
    flex-direction: column;
}

.brand-title .en {
    font-size: 1.05rem;
    font-weight: 800;
    letter-spacing: 0.5px;
}

.brand-title .subtitle {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-top: 1px;
}

/* User Profile Widget inside Sidebar */
.user-panel {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 1.2rem;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

body.light-theme .user-panel {
    background: rgba(15, 23, 42, 0.02);
}

.user-greeting {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-primary);
}

.sync-status {
    font-size: 0.78rem;
    font-weight: 600;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}
/* Sidebar section labels */
.sidebar-section-label {
    font-size: 0.72rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-top: 0.5rem;
    margin-bottom: -0.2rem;
    padding-left: 0.5rem;
}

/* Page Menu Page tabs */
.page-menu {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.page-tab {
    background: none;
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 0.8rem 1.2rem;
    border-radius: 14px;
    text-align: left;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-size: 0.9rem;
    font-weight: 600;
    transition: var(--transition-smooth);
    width: 100%;
}

.page-tab i {
    font-size: 1rem;
    color: var(--text-muted);
    transition: var(--transition-smooth);
}

.page-tab:hover {
    background-color: rgba(255, 255, 255, 0.04);
    border-color: var(--card-border);
    color: var(--text-primary);
    transform: translateX(4px);
}

.page-tab:active {
    transform: scale(0.96) translateX(4px);
}

body.light-theme .page-tab:hover {
    background-color: rgba(15, 23, 42, 0.03);
}

.page-tab.active {
    background: linear-gradient(135deg, var(--accent-indigo-glow), rgba(99, 102, 241, 0.05));
    border-color: var(--card-border-active);
    color: var(--text-primary);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.05);
}

.page-tab.active i {
    color: var(--accent-indigo);
}

/* Views switching */
.app-view {
    display: none;
    flex-direction: column;
    gap: 2rem;
    opacity: 0;
}

.app-view.active {
    display: flex !important;
    animation: viewFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes viewFadeIn {
    0% {
        opacity: 0;
        transform: translateY(12px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Navigation Menu */
.nav-menu {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
    flex-grow: 1;
    padding-right: 2px;
}

.nav-tab {
    background: none;
    border: 1px solid transparent;
    color: var(--text-secondary);
    padding: 1rem 1.2rem;
    border-radius: 16px;
    text-align: left;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    transition: var(--transition-smooth);
    width: 100%;
}

.nav-tab:hover {
    background-color: rgba(255, 255, 255, 0.04);
    border-color: var(--card-border);
    color: var(--text-primary);
    transform: translateX(4px);
}

.nav-tab:active {
    transform: scale(0.96) translateX(4px);
}

body.light-theme .nav-tab:hover {
    background-color: rgba(15, 23, 42, 0.03);
}

.nav-tab.active {
    background: linear-gradient(135deg, var(--accent-indigo-glow), rgba(99, 102, 241, 0.05));
    border-color: var(--card-border-active);
    color: var(--text-primary);
    box-shadow: 0 4px 15px rgba(99, 102, 241, 0.05);
}

.nav-tab .tab-title-en {
    font-size: 0.9rem;
    font-weight: 600;
}

.tab-mini-progress {
    width: 100%;
    height: 5px;
    background-color: rgba(255, 255, 255, 0.08);
    border-radius: 3px;
    margin-top: 0.5rem;
    overflow: hidden;
}

body.light-theme .tab-mini-progress {
    background-color: rgba(15, 23, 42, 0.08);
}

.tab-mini-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent-indigo), var(--accent-cyan));
    border-radius: 3px;
    transition: var(--transition-smooth);
}

/* Logout Button */
.logout-btn {
    background: rgba(239, 68, 68, 0.05);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: #f87171;
    padding: 0.9rem;
    border-radius: 16px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.6rem;
    transition: var(--transition-smooth);
    width: 100%;
}

.logout-btn:hover {
    background-color: rgba(239, 68, 68, 0.15);
    border-color: #ef4444;
    color: #ffffff;
    box-shadow: 0 4px 15px rgba(239, 68, 68, 0.15);
}

.logout-btn:active {
    transform: scale(0.96);
}

/* ============================================================
   Main Content Area
   ============================================================ */
.main-content {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

/* Global Stats Board */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.2rem;
}

.stat-card {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 16px;
    padding: 1rem 1.2rem;
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    position: relative;
    overflow: hidden;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    transition: var(--transition-smooth);
}

.stat-card:hover {
    transform: translateY(-4px);
    border-color: var(--card-border-active);
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-indigo), var(--accent-cyan));
}

.stat-card.theory-card::before {
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-indigo));
}

.stat-card.papers-card::before {
    background: linear-gradient(90deg, var(--accent-emerald), var(--accent-cyan));
}

.stat-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.stat-names {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.stat-label-en {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-primary);
}

.stat-label-muted {
    font-size: 0.72rem;
    color: var(--text-muted);
}

.stat-icon {
    font-size: 1.1rem;
    color: var(--text-muted);
}

.stat-value {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-progress-bar-wrapper {
    background-color: rgba(255, 255, 255, 0.08);
    height: 10px;
    border-radius: 5px;
    width: 100%;
    overflow: hidden;
}

body.light-theme .stat-progress-bar-wrapper {
    background-color: rgba(15, 23, 42, 0.08);
}

.stat-progress-bar {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--accent-indigo), var(--accent-cyan));
    border-radius: 5px;
    transition: var(--transition-smooth);
}

/* Bilingual Study Instructions Banner */
.instruction-banner {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.08), rgba(6, 182, 212, 0.08));
    border: 1px solid rgba(99, 102, 241, 0.2);
    border-left: 6px solid var(--accent-indigo);
    border-radius: 20px;
    padding: 1.5rem;
    display: flex;
    gap: 1.2rem;
    align-items: flex-start;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}

.instruction-icon {
    font-size: 1.8rem;
    color: var(--accent-indigo);
    animation: glowAnimation 1.5s infinite alternate;
}

@keyframes glowAnimation {
    0% { transform: scale(1); filter: drop-shadow(0 0 2px var(--accent-indigo)); }
    100% { transform: scale(1.08); filter: drop-shadow(0 0 8px var(--accent-indigo)); }
}

.instruction-body {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    width: 100%;
}

.instruction-title-si {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--text-primary);
}

.instruction-text-si {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Control Hub Styling */
.controls-hub {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 1.5rem;
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 1.2rem;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}

.search-wrapper {
    position: relative;
    flex-grow: 1;
    min-width: 300px;
}

.search-wrapper i {
    position: absolute;
    left: 1.2rem;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    font-size: 1rem;
}

.search-input {
    background-color: rgba(0, 0, 0, 0.25);
    border: 1.5px solid var(--card-border);
    border-radius: 14px;
    width: 100%;
    padding: 0.9rem 1.2rem 0.9rem 3rem;
    color: var(--text-primary);
    font-family: var(--font-si);
    font-size: 0.95rem;
    outline: none;
    transition: var(--transition-smooth);
}

body.light-theme .search-input {
    background-color: rgba(15, 23, 42, 0.03);
}

.search-input:focus {
    border-color: var(--accent-indigo);
    box-shadow: 0 0 12px var(--accent-indigo-glow);
    background-color: rgba(0, 0, 0, 0.35);
}

body.light-theme .search-input:focus {
    background-color: #ffffff;
}

.filters-wrapper {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.filter-btn {
    background-color: rgba(255, 255, 255, 0.04);
    border: 1.5px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.7rem 1.2rem;
    border-radius: 12px;
    font-size: 0.85rem;
    cursor: pointer;
    font-weight: 600;
    transition: var(--transition-smooth);
}

body.light-theme .filter-btn {
    background-color: rgba(15, 23, 42, 0.02);
}

.filter-btn:hover {
    color: var(--text-primary);
    border-color: var(--text-muted);
    background-color: rgba(255, 255, 255, 0.08);
}

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

.filter-btn.active {
    background-color: var(--accent-indigo);
    border-color: var(--accent-indigo);
    color: white;
    box-shadow: 0 4px 15px var(--accent-indigo-glow);
}

/* Utilities (Theme and database reset) */
.utilities-wrapper {
    display: flex;
    gap: 0.8rem;
}

.util-btn {
    background: none;
    border: 1.5px solid var(--card-border);
    color: var(--text-secondary);
    width: 46px;
    height: 46px;
    border-radius: 12px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    position: relative;
    transition: var(--transition-smooth);
}

.util-btn:hover {
    background-color: rgba(255, 255, 255, 0.06);
    color: var(--text-primary);
    border-color: var(--text-secondary);
}

.util-btn:active {
    transform: scale(0.91);
}

body.light-theme .util-btn:hover {
    background-color: rgba(15, 23, 42, 0.04);
}

.util-btn.danger-btn:hover {
    color: #ef4444;
    border-color: #ef4444;
    background-color: rgba(239, 68, 68, 0.05);
}

.util-btn::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: 125%;
    left: 50%;
    transform: translateX(-50%) scale(0.85);
    background-color: #0f172a;
    border: 1px solid var(--card-border);
    color: #ffffff;
    padding: 0.5rem 0.8rem;
    border-radius: 8px;
    font-size: 0.78rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: var(--transition-smooth);
    box-shadow: var(--shadow-premium);
}

.util-btn:hover::after {
    opacity: 1;
    transform: translateX(-50%) scale(1);
}

/* Dynamic Syllabus Paper Header */
.syllabus-header {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 1.5rem 2rem;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}

.paper-title-en {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--accent-indigo);
    margin-bottom: 0.4rem;
}

.paper-description {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* ============================================================
   Redesigned Question & Lesson Checklist Cards
   ============================================================ */
.cards-container {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

.question-card {
    background: var(--card-bg);
    border: 1.5px solid var(--card-border);
    border-radius: 24px;
    padding: 1.8rem;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    transition: var(--transition-smooth);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    opacity: 0;
    animation: cardFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes cardFadeIn {
    0% {
        opacity: 0;
        transform: translateY(10px);
    }
    100% {
        opacity: 1;
        transform: translateY(0);
    }
}

.question-card:hover {
    transform: translateY(-2px);
    border-color: var(--card-border-active);
    box-shadow: 0 20px 40px -10px rgba(0, 0, 0, 0.5);
}

body.light-theme .question-card:hover {
    box-shadow: 0 15px 30px -8px rgba(15, 23, 42, 0.06);
}

/* Structured card top border highlighting */
.structured-card {
    border-top: 4px solid var(--accent-indigo);
}

.simple-card {
    border-top: 4px solid var(--accent-cyan);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--card-border);
    padding-bottom: 1rem;
}

.card-badge {
    background-color: var(--accent-indigo-glow);
    color: var(--text-primary);
    padding: 0.4rem 1rem;
    border-radius: 10px;
    font-size: 0.82rem;
    font-weight: 700;
    border: 1px solid rgba(99, 102, 241, 0.25);
}

.parts-container {
    display: flex;
    flex-direction: column;
    gap: 1.8rem;
}

/* Each structured question sub-part row */
.part-row {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    padding: 0.5rem 0;
}

.part-row:not(:last-child) {
    border-bottom: 1px dashed var(--card-border);
    padding-bottom: 1.8rem;
}

.part-details {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.part-identifier {
    background-color: var(--bg-primary);
    border: 1.5px solid var(--card-border);
    color: var(--accent-indigo);
    width: 32px;
    height: 32px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 800;
    font-size: 0.95rem;
    flex-shrink: 0;
}

.part-names {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.part-si {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
}

.part-marks-pill {
    background-color: rgba(255, 255, 255, 0.05);
    border: 1.5px solid var(--card-border);
    color: var(--text-secondary);
    padding: 0.35rem 0.8rem;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
    flex-shrink: 0;
}

body.light-theme .part-marks-pill {
    background-color: rgba(15, 23, 42, 0.03);
}

/* Simple Part A question template formatting */
.card-body-simple {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.simple-card-header {
    display: flex;
    align-items: center;
    gap: 1.2rem;
    flex-wrap: wrap;
}

.card-q-number {
    background-color: rgba(6, 182, 212, 0.15);
    border: 1px solid rgba(6, 182, 212, 0.3);
    color: var(--text-primary);
    padding: 0.4rem 1rem;
    border-radius: 10px;
    font-size: 0.82rem;
    font-weight: 700;
}

.simple-card-title {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.simple-title-si {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
}

.card-marks-badge {
    background-color: rgba(6, 182, 212, 0.08);
    border: 1.5px solid rgba(6, 182, 212, 0.25);
    color: var(--text-primary);
    padding: 0.35rem 0.8rem;
    border-radius: 8px;
    font-size: 0.8rem;
    font-weight: 600;
}

/* Action grids containing Theory checks and Past Paper buttons */
.part-action-grid {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: 2rem;
    align-items: center;
    background-color: rgba(0, 0, 0, 0.2);
    border: 1.5px solid var(--card-border);
    border-radius: 16px;
    padding: 1.2rem;
}

body.light-theme .part-action-grid {
    background-color: rgba(15, 23, 42, 0.015);
}

@media (max-width: 960px) {
    .part-action-grid {
        grid-template-columns: 1fr;
        gap: 1.2rem;
    }
}

/* Premium Custom Checkbox */
.custom-checkbox {
    display: flex;
    align-items: center;
    gap: 1rem;
    cursor: pointer;
    position: relative;
    user-select: none;
}

.custom-checkbox input {
    position: absolute;
    opacity: 0;
    cursor: pointer;
    height: 0;
    width: 0;
}

.checkmark {
    position: relative;
    height: 24px;
    width: 24px;
    background-color: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.25);
    border-radius: 8px;
    transition: var(--transition-smooth);
    flex-shrink: 0;
}

body.light-theme .checkmark {
    background-color: rgba(15, 23, 42, 0.03);
    border-color: rgba(15, 23, 42, 0.35);
}

.custom-checkbox:hover input ~ .checkmark {
    border-color: var(--accent-indigo);
    box-shadow: 0 0 10px var(--accent-indigo-glow);
}

.custom-checkbox input:checked ~ .checkmark {
    background-color: var(--accent-indigo);
    border-color: var(--accent-indigo);
    box-shadow: 0 0 12px var(--accent-indigo-glow);
}

.checkmark::after {
    content: "";
    position: absolute;
    left: 8px;
    top: 4px;
    width: 5px;
    height: 10px;
    border: solid white;
    border-width: 0 2.5px 2.5px 0;
    transform: rotate(45deg) scale(0);
    opacity: 0;
    transition: transform 0.22s cubic-bezier(0.34, 1.56, 0.64, 1), opacity 0.15s ease;
}

.custom-checkbox input:checked ~ .checkmark::after {
    transform: rotate(45deg) scale(1);
    opacity: 1;
}

.checkbox-label {
    display: flex;
    flex-direction: column;
}

.label-en {
    font-size: 0.95rem;
    font-weight: 600;
}

/* Past Papers Grid */
.past-papers-wrapper {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    width: 100%;
}

.past-papers-title {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.papers-badge {
    background-color: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--card-border);
    padding: 0.2rem 0.6rem;
    border-radius: 6px;
    font-size: 0.78rem;
    font-weight: 700;
}

body.light-theme .papers-badge {
    background-color: rgba(15, 23, 42, 0.03);
}

.papers-badge.all-done {
    background-color: var(--accent-emerald-glow);
    border-color: var(--accent-emerald);
    color: var(--accent-emerald);
}

.year-badges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
    gap: 0.5rem;
}

/* Redesigned Year Badge Button */
.year-badge {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1.5px solid rgba(255, 255, 255, 0.2);
    color: var(--text-secondary);
    padding: 0.6rem 0.3rem;
    border-radius: 10px;
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    text-align: center;
    outline: none;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.3rem;
}

body.light-theme .year-badge {
    background-color: rgba(15, 23, 42, 0.02);
    border-color: rgba(15, 23, 42, 0.25);
}

.year-badge:hover {
    border-color: var(--text-primary);
    color: var(--text-primary);
    transform: translateY(-2px);
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.2);
}

.year-badge:active {
    transform: translateY(0) scale(0.91);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* Checked/Completed state of year badges */
.year-badge.completed {
    background-color: var(--accent-emerald) !important;
    border-color: var(--accent-emerald) !important;
    color: white !important;
    box-shadow: 0 4px 12px var(--accent-emerald-glow) !important;
}

.year-badge.completed:hover {
    filter: brightness(1.15);
    transform: translateY(-2px);
}

.year-badge.completed:active {
    transform: translateY(0) scale(0.91);
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.check-tick {
    font-size: 0.78rem;
    display: inline-block;
    animation: tickPopIn 0.25s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

@keyframes tickPopIn {
    0% {
        transform: scale(0);
        opacity: 0;
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

/* Yearly Progress Card Grid */
.yearly-progress-section {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 2rem;
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    margin-top: 1.5rem;
}

.yearly-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}

.year-progress-card {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1.5px solid var(--card-border);
    border-radius: 20px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    transition: var(--transition-smooth);
    position: relative;
    overflow: hidden;
    opacity: 0;
    animation: cardFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

body.light-theme .year-progress-card {
    background-color: rgba(15, 23, 42, 0.01);
}

.year-progress-card:hover {
    transform: translateY(-4px);
    border-color: var(--card-border-active);
    box-shadow: var(--shadow-premium);
}

/* Glowing borders/accents based on completion */
.year-progress-card.perfect-score {
    border-color: var(--accent-emerald);
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.2), var(--shadow-premium);
}
.year-progress-card.perfect-score::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-emerald), #34d399);
}

.year-progress-card.high-score {
    border-color: var(--accent-cyan);
    box-shadow: 0 0 12px rgba(6, 182, 212, 0.15), var(--shadow-premium);
}
.year-progress-card.high-score::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: linear-gradient(90deg, var(--accent-cyan), var(--accent-indigo));
}

.year-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.year-card-title {
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--text-primary);
}

.year-card-percent {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--accent-indigo);
}
.year-progress-card.perfect-score .year-card-percent {
    color: var(--accent-emerald);
}
.year-progress-card.high-score .year-card-percent {
    color: var(--accent-cyan);
}

.year-card-metrics {
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.year-metric-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.88rem;
    color: var(--text-secondary);
}

.year-metric-val {
    font-weight: 700;
    color: var(--text-primary);
}

.year-metric-row.total-row {
    border-top: 1px solid var(--card-border);
    padding-top: 0.6rem;
    margin-top: 0.2rem;
    font-weight: 700;
}

.year-metric-valHighlight {
    font-weight: 800;
    color: var(--accent-indigo);
    font-size: 0.95rem;
}
.year-progress-card.perfect-score .year-metric-valHighlight {
    color: var(--accent-emerald);
}
.year-progress-card.high-score .year-metric-valHighlight {
    color: var(--accent-cyan);
}

.year-progress-wrapper {
    height: 8px;
    background-color: rgba(255, 255, 255, 0.08);
    border-radius: 4px;
    width: 100%;
    overflow: hidden;
}

body.light-theme .year-progress-wrapper {
    background-color: rgba(15, 23, 42, 0.08);
}

.year-progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-indigo), var(--accent-cyan));
    border-radius: 4px;
    transition: var(--transition-smooth);
}
.year-progress-card.perfect-score .year-progress-bar {
    background: linear-gradient(90deg, var(--accent-emerald), #34d399);
}

/* Detail Breakdown Grid Panel */
.stats-breakdown-section {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 24px;
    padding: 2rem;
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}

.breakdown-title-en {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
}

.breakdown-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
    gap: 1.5rem;
}

.breakdown-card {
    background-color: rgba(255, 255, 255, 0.02);
    border: 1.5px solid var(--card-border);
    border-radius: 18px;
    padding: 1.2rem;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    transition: var(--transition-smooth);
    opacity: 0;
    animation: cardFadeIn 0.35s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

.breakdown-card:nth-child(1) { animation-delay: 0.04s; }
.breakdown-card:nth-child(2) { animation-delay: 0.08s; }
.breakdown-card:nth-child(3) { animation-delay: 0.12s; }
.breakdown-card:nth-child(4) { animation-delay: 0.16s; }

body.light-theme .breakdown-card {
    background-color: rgba(15, 23, 42, 0.01);
}

.breakdown-card:hover {
    border-color: var(--card-border-active);
}

.breakdown-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.breakdown-card-title-en {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
}

.breakdown-percent {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--accent-indigo);
}

.breakdown-metrics {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.breakdown-metric-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.82rem;
    color: var(--text-secondary);
}

.breakdown-metric-val {
    font-weight: 700;
    color: var(--text-primary);
}

.breakdown-progress-wrapper {
    height: 6px;
    background-color: rgba(255, 255, 255, 0.08);
    border-radius: 3px;
    width: 100%;
    overflow: hidden;
}

body.light-theme .breakdown-progress-wrapper {
    background-color: rgba(15, 23, 42, 0.08);
}

/* Empty Search Results Container */
.no-results-state {
    text-align: center;
    padding: 4rem 2rem;
    background-color: rgba(0, 0, 0, 0.15);
    border: 2px dashed var(--card-border);
    border-radius: 24px;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 1rem;
}

.no-results-state i {
    color: var(--text-muted);
}

.no-results-state p {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* ============================================================
   Redesigned Frosted Glass Auth Screens Overlay
   ============================================================ */
.auth-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(5, 7, 13, 0.88);
    backdrop-filter: blur(28px);
    -webkit-backdrop-filter: blur(28px);
    display: flex;
    align-items: flex-start;
    justify-content: center;
    z-index: 99999;
    padding: 2rem 1.5rem;
    overflow-y: auto;
}

.auth-box {
    background: rgba(15, 21, 37, 0.65);
    border: 1.5px solid rgba(255, 255, 255, 0.12);
    box-shadow: 0 30px 70px rgba(0, 0, 0, 0.8), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    border-radius: 28px;
    padding: 2.5rem;
    width: 100%;
    max-width: 460px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    align-items: stretch;
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    animation: authBoxFadeIn 0.5s cubic-bezier(0.16, 1, 0.3, 1);
    margin: auto;
}

body.light-theme .auth-box {
    background: rgba(255, 255, 255, 0.85);
    border-color: rgba(15, 23, 42, 0.12);
    box-shadow: 0 30px 60px rgba(15, 23, 42, 0.12);
}

@keyframes authBoxFadeIn {
    0% { transform: translateY(30px) scale(0.95); opacity: 0; }
    100% { transform: translateY(0) scale(1); opacity: 1; }
}

.auth-logo {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
    color: white;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.6rem;
    margin: 0 auto;
    box-shadow: 0 8px 24px var(--accent-indigo-glow);
}

.auth-title {
    font-size: 1.5rem;
    font-weight: 700;
    text-align: center;
    background: linear-gradient(135deg, #ffffff, #93c5fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

body.light-theme .auth-title {
    background: linear-gradient(135deg, var(--text-primary), var(--accent-indigo));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.auth-subtitle {
    font-size: 0.85rem;
    color: var(--text-muted);
    text-align: center;
    line-height: 1.5;
    margin-top: -0.8rem;
}

.auth-tabs {
    display: grid;
    grid-template-columns: 1fr 1fr;
    background-color: rgba(0, 0, 0, 0.3);
    border: 1.5px solid var(--card-border);
    border-radius: 12px;
    padding: 0.3rem;
}

body.light-theme .auth-tabs {
    background-color: rgba(15, 23, 42, 0.05);
}

.auth-tab {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 0.6rem;
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    border-radius: 9px;
    transition: var(--transition-smooth);
}

.auth-tab.active {
    background-color: var(--accent-indigo);
    color: white;
    box-shadow: 0 4px 12px var(--accent-indigo-glow);
}

.auth-form {
    display: flex;
    flex-direction: column;
    gap: 1.1rem;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.input-group label {
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
}

/* Redesigned High-Contrast Input Fields */
.input-group input {
    background-color: rgba(0, 0, 0, 0.3);
    border: 2px solid rgba(255, 255, 255, 0.25);
    border-radius: 12px;
    padding: 0.85rem 1.1rem;
    color: var(--text-primary);
    outline: none;
    font-size: 0.9rem;
    transition: var(--transition-smooth);
    width: 100%;
}

body.light-theme .input-group input {
    background-color: rgba(15, 23, 42, 0.02);
    border-color: rgba(15, 23, 42, 0.25);
}

.input-group input:focus {
    border-color: var(--accent-indigo);
    box-shadow: 0 0 10px var(--accent-indigo-glow);
    background-color: rgba(0, 0, 0, 0.45);
}

body.light-theme .input-group input:focus {
    background-color: #ffffff;
}

.auth-btn {
    background: linear-gradient(135deg, var(--accent-indigo), #4f46e5);
    border: none;
    color: white;
    padding: 0.9rem;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 700;
    cursor: pointer;
    box-shadow: 0 6px 20px var(--accent-indigo-glow);
    transition: var(--transition-smooth);
    margin-top: 0.4rem;
}

.auth-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(99, 102, 241, 0.5);
}

.auth-btn:active {
    transform: scale(0.96) translateY(0);
}

.auth-link {
    color: var(--text-muted);
    font-size: 0.8rem;
    text-align: center;
    text-decoration: none;
    transition: var(--transition-smooth);
    font-weight: 500;
}

.auth-link:hover {
    color: var(--accent-indigo);
}

.auth-form-title {
    font-size: 1.1rem;
    font-weight: 700;
    text-align: center;
}

.auth-form-desc {
    font-size: 0.8rem;
    color: var(--text-secondary);
    text-align: center;
    line-height: 1.5;
    margin-bottom: 0.4rem;
}

/* Google Sign-In Button */
.auth-divider {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    color: var(--text-muted);
    font-size: 0.78rem;
    font-weight: 500;
}

.auth-divider::before,
.auth-divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: var(--card-border);
}

.google-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    width: 100%;
    padding: 0.85rem 1rem;
    background: #ffffff;
    border: 1.5px solid rgba(0, 0, 0, 0.12);
    border-radius: 12px;
    color: #3c4043;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    box-shadow: 0 2px 8px rgba(0,0,0,0.12);
}

.google-btn:hover {
    background: #f8f9fa;
    box-shadow: 0 4px 14px rgba(0,0,0,0.18);
    transform: translateY(-1px);
}

.google-btn:active {
    transform: translateY(0) scale(0.96);
}
.auth-msg {
    font-size: 0.8rem;
    padding: 0.75rem 1rem;
    border-radius: 10px;
    display: none;
    line-height: 1.5;
    text-align: center;
    font-weight: 600;
    border: 1.5px solid transparent;
}

.auth-msg.error {
    display: block;
    background-color: rgba(239, 68, 68, 0.1);
    border-color: rgba(239, 68, 68, 0.25);
    color: #fca5a5;
}

body.light-theme .auth-msg.error {
    color: #ef4444;
}

.auth-msg.success {
    display: block;
    background-color: var(--accent-emerald-glow);
    border-color: rgba(16, 185, 129, 0.25);
    color: #6ee7b7;
}

body.light-theme .auth-msg.success {
    color: #059669;
}

/* ============================================================
   Theme Toggle Slider (Dual Light/Dark Button)
   ============================================================ */
.theme-toggle-track {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    padding: 0.45rem 0.7rem;
    border-radius: 30px;
    border: 1.5px solid var(--card-border);
    background-color: rgba(15, 23, 42, 0.04);
    transition: var(--transition-smooth);
    user-select: none;
    outline: none;
    height: 46px;
    flex-shrink: 0;
}

body.light-theme .theme-toggle-track {
    background-color: rgba(15, 23, 42, 0.03);
}

.theme-toggle-track:hover {
    border-color: var(--accent-indigo);
    box-shadow: 0 0 0 3px var(--accent-indigo-glow);
}

.theme-toggle-track:focus-visible {
    outline: 2px solid var(--accent-indigo);
    outline-offset: 2px;
}

.tt-sun, .tt-moon {
    font-size: 0.88rem;
    color: var(--text-muted);
    transition: var(--transition-smooth);
    flex-shrink: 0;
}

body.light-theme .tt-sun {
    color: var(--accent-orange);
}

body:not(.light-theme) .tt-moon {
    color: var(--accent-cyan);
}

.tt-pill {
    width: 40px;
    height: 22px;
    background-color: rgba(255, 255, 255, 0.06);
    border-radius: 11px;
    position: relative;
    border: 1.5px solid var(--card-border);
    transition: background-color 0.25s ease;
    flex-shrink: 0;
}

body.light-theme .tt-pill {
    background-color: rgba(15, 23, 42, 0.06);
}

/* Thumb starts on LEFT = dark mode (default pill shows moon side) */
.tt-thumb {
    position: absolute;
    width: 16px;
    height: 16px;
    border-radius: 50%;
    background: var(--accent-cyan);
    top: 1px;
    left: 1px;
    transition: left 0.25s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.25s ease, box-shadow 0.25s ease;
    box-shadow: 0 2px 8px var(--accent-cyan-glow);
}

/* In LIGHT mode, thumb slides to RIGHT (toward moon icon = currently inactive) */
body.light-theme .tt-thumb {
    left: 21px;
    background: var(--accent-indigo);
    box-shadow: 0 2px 8px var(--accent-indigo-glow);
}

/* ============================================================
   Mobile Header (Fixed Top Bar, hidden on desktop)
   ============================================================ */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 62px;
    background: var(--bg-sidebar);
    border-bottom: 1px solid var(--card-border);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    z-index: 400;
    align-items: center;
    padding: 0 1.2rem;
    gap: 1rem;
}

.mobile-brand-text {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text-primary);
    letter-spacing: 0.3px;
    flex: 1;
}

/* Hamburger / Close Button */
.hamburger-btn {
    background: none;
    border: 1.5px solid var(--card-border);
    border-radius: 10px;
    width: 42px;
    height: 42px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
    padding: 8px;
    transition: var(--transition-smooth);
    flex-shrink: 0;
}

.hamburger-btn:hover {
    border-color: var(--accent-indigo);
    background-color: var(--accent-indigo-glow);
}

.hamburger-btn span {
    display: block;
    width: 20px;
    height: 2px;
    background-color: var(--text-primary);
    border-radius: 2px;
    transition: var(--transition-smooth);
    transform-origin: center;
}

.hamburger-btn.active span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.hamburger-btn.active span:nth-child(2) {
    opacity: 0;
    transform: scaleX(0);
}

.hamburger-btn.active span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ============================================================
   Sidebar Backdrop Overlay (Mobile only)
   ============================================================ */
.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(5, 7, 13, 0.62);
    z-index: 450;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.35s cubic-bezier(0.16, 1, 0.3, 1), visibility 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.sidebar-overlay.visible {
    opacity: 1;
    visibility: visible;
}

/* Sidebar theme toggle row at the very top */
.sidebar-theme-toggle-row {
    display: flex;
    justify-content: flex-end;
    padding-bottom: 0.8rem;
    border-bottom: 1px solid var(--card-border);
    margin-bottom: 0.5rem;
}

/* ============================================================
   Subject Toggle Card (Sidebar)
   ============================================================ */
.subject-toggle-card {
    display: block;
    width: 100%;
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 0.6rem;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
}
body.light-theme .subject-toggle-card {
    background: rgba(255, 255, 255, 0.7);
}

.subject-toggle-track {
    display: flex;
    align-items: center;
    background: rgba(0, 0, 0, 0.25);
    border: 1.5px solid var(--card-border);
    border-radius: 14px;
    padding: 4px;
    position: relative;
    cursor: pointer;
    width: 100%;
    height: 48px;
    user-select: none;
    transition: var(--transition-smooth);
}

.subject-toggle-track:active {
    transform: scale(0.97);
}
body.light-theme .subject-toggle-track {
    background: rgba(15, 23, 42, 0.04);
}

.subject-toggle-pill {
    position: absolute;
    top: 4px;
    left: 4px;
    bottom: 4px;
    width: calc(50% - 4px);
    background: linear-gradient(135deg, var(--accent-indigo), var(--accent-cyan));
    border-radius: 10px;
    transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
    box-shadow: 0 4px 12px var(--accent-indigo-glow);
}

.subject-toggle-track.applied-active .subject-toggle-pill {
    transform: translateX(100%);
}

.subject-toggle-label {
    flex: 1;
    text-align: center;
    font-size: 0.82rem;
    font-weight: 700;
    z-index: 2;
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

.subject-toggle-label.active {
    color: #ffffff !important;
}

/* ============================================================
   Desktop Columns (Side-by-side layout)
   ============================================================ */
.desktop-columns {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    width: 100%;
}

.column-part {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.column-header {
    background: var(--card-bg);
    border: 1px solid var(--card-border);
    border-radius: 20px;
    padding: 1.2rem 1.5rem;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
}

.column-header h2 {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--accent-indigo);
}

.column-part:nth-child(2) .column-header h2 {
    color: var(--accent-cyan);
}

.column-subtitle {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.column-cards-list {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

/* ============================================================
   Responsive Layout Media Queries
   ============================================================ */
@media (max-width: 900px) {
    /* Mobile navigation & toggle controls */
    .nav-menu {
        display: flex !important;
    }
    .desktop-columns {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    /* Reveal mobile header bar */
    .mobile-header {
        display: flex;
    }

    /* Push page content below the fixed 62px header */
    body {
        padding-top: 62px;
    }

    /* Single-column layout */
    .app-container {
        grid-template-columns: 1fr;
        padding: 1.2rem;
        gap: 1.5rem;
    }

    /* Sidebar becomes a slide-in left drawer */
    .sidebar {
        position: fixed;
        top: 0;
        left: -320px;
        width: 300px;
        height: 100vh;
        z-index: 500;
        border-radius: 0 24px 24px 0;
        overflow-y: auto;
        transition: left 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease;
        padding: 1.5rem 1.2rem;
        border-top: none;
        border-bottom: none;
        border-left: none;
    }

    .sidebar.open {
        left: 0;
        box-shadow: 8px 0 40px rgba(0, 0, 0, 0.5);
    }
}

@media (max-width: 640px) {
    .app-container {
        padding: 1rem;
        gap: 1.2rem;
    }

    .controls-hub {
        flex-direction: column;
        align-items: stretch;
    }

    .filters-wrapper {
        justify-content: center;
    }

    .utilities-wrapper {
        justify-content: center;
    }

    .part-details {
        flex-direction: column;
        align-items: flex-start;
    }

    .part-marks-pill {
        align-self: flex-start;
    }

    .auth-box {
        padding: 2rem 1.5rem;
    }

    /* Fix auth overlay scroll on small phones — align top so box isn't cut off */
    .auth-overlay {
        align-items: flex-start;
        padding-top: 1rem;
        padding-bottom: 2rem;
    }

    .year-badges-grid {
        grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
    }
}