/* Style overrides and custom premium styling for Irish Electrical Mathematics Hub */

/* Root CSS Variables for Light Theme Only */
:root {
    /* Fonts */
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    
    /* Transitions */
    --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-normal: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout Sizes */
    --sidebar-width: 265px;
    --topbar-height: 70px;
    --border-radius-sm: 6px;
    --border-radius-md: 12px;
    --border-radius-lg: 20px;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.15), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Theme variables (Light Theme) */
    --bg-primary: transparent;
    --bg-secondary: rgba(255, 255, 255, 0.35);
    --bg-card: rgba(255, 255, 255, 0.65);
    --border-color: rgba(255, 255, 255, 0.45);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --primary-color: #169b62;
    --primary-hover: #117c4e;
    --primary-glow: rgba(22, 155, 98, 0.08);
    --accent-color: #ff883e;
    
    --success: #059669;
    --success-bg: rgba(5, 150, 105, 0.06);
    --success-border: rgba(5, 150, 105, 0.15);
    --danger: #dc2626;
    --danger-bg: rgba(220, 38, 38, 0.06);
    --danger-border: rgba(220, 38, 38, 0.15);
    --warning: #d97706;
    --warning-bg: rgba(217, 119, 6, 0.06);
    --warning-border: rgba(217, 119, 6, 0.15);
    --info: #2563eb;
    --info-bg: rgba(37, 99, 235, 0.06);
    --info-border: rgba(37, 99, 235, 0.15);
    --note: #475569;
    --note-bg: rgba(71, 85, 105, 0.06);
    --note-border: rgba(71, 85, 105, 0.15);
    
    --scrollbar-track: #f1f5f9;
    --scrollbar-thumb: #cbd5e1;
}

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

body {
    background: radial-gradient(circle at 10% 10%, rgba(22, 155, 98, 0.06) 0%, transparent 40%),
                radial-gradient(circle at 90% 90%, rgba(255, 136, 62, 0.06) 0%, transparent 45%),
                #eef2f5;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 16px;
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    overflow-x: hidden;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* App Container Layout */
.app-container {
    display: flex;
    width: 100vw;
    height: 100vh;
    overflow: hidden;
    position: relative;
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--scrollbar-track);
}
::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

/* Sidebar Styling */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    backdrop-filter: blur(15px) saturate(180%);
    -webkit-backdrop-filter: blur(15px) saturate(180%);
    display: flex;
    flex-direction: column;
    height: 100%;
    z-index: 100;
    flex-shrink: 0;
    transition: transform var(--transition-normal), background-color var(--transition-normal), border-color var(--transition-normal);
}

.sidebar-header {
    padding: 24px;
    display: flex;
    justify-content: center;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
}

.logo-container {
    position: relative;
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

.logo-glow {
    position: absolute;
    top: -4px;
    left: -4px;
    right: -4px;
    bottom: -4px;
    border-radius: 50%;
    background: var(--primary-color);
    opacity: 0.4;
    filter: blur(8px);
    animation: logo-glow-pulse 3s infinite alternate;
}

.logo-icon {
    position: relative;
    width: 100%;
    height: 100%;
    border-radius: 50%;
    background: var(--primary-color);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #ffffff;
    font-size: 2rem;
    box-shadow: 0 8px 20px rgba(22, 155, 98, 0.3);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.logo-icon::after {
    content: '';
    position: absolute;
    top: -6px;
    left: -6px;
    right: -6px;
    bottom: -6px;
    border: 2px dashed rgba(22, 155, 98, 0.4);
    border-radius: 50%;
    animation: logo-spin 25s linear infinite;
}

.logo-container:hover .logo-icon {
    transform: scale(1.08) rotate(15deg);
    box-shadow: 0 12px 28px rgba(22, 155, 98, 0.5);
}

.logo-container:hover .logo-glow {
    opacity: 0.7;
    filter: blur(12px);
}

@keyframes logo-glow-pulse {
    0% {
        transform: scale(0.95);
        opacity: 0.3;
    }
    100% {
        transform: scale(1.1);
        opacity: 0.6;
    }
}

@keyframes logo-spin {
    100% {
        transform: rotate(360deg);
    }
}


.sidebar-nav {
    flex-grow: 1;
    padding: 24px 16px;
    overflow-y: auto;
}

.sidebar-nav ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.sidebar-nav .nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--border-radius-md);
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 500;
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.sidebar-nav .nav-item i {
    font-size: 1.1rem;
    width: 20px;
    text-align: center;
    transition: transform var(--transition-fast);
}

.sidebar-nav .nav-item:hover {
    color: var(--text-primary);
    background-color: var(--bg-card);
}

.sidebar-nav .nav-item:hover i {
    transform: translateX(2px);
}

.sidebar-nav .nav-item.active {
    color: #ffffff;
    background: linear-gradient(135deg, var(--primary-color), #117c4e);
    box-shadow: 0 4px 12px var(--primary-glow);
}

.sidebar-nav .nav-item-divider {
    font-size: 0.725rem;
    font-weight: 700;
    text-transform: uppercase;
    color: var(--text-secondary);
    letter-spacing: 1.2px;
    margin-top: 20px;
    margin-bottom: 6px;
    padding-left: 16px;
    opacity: 0.7;
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 16px;
    background-color: rgba(0,0,0,0.05);
}

.theme-toggle-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.theme-toggle-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
    box-shadow: 0 0 10px var(--primary-glow);
}

.author-tag {
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-align: center;
    font-weight: 500;
}

/* Main Content Area */
.main-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    height: 100%;
    overflow: hidden;
    position: relative;
    background-color: var(--bg-primary);
}

/* Top Bar Styling */
.top-bar {
    height: var(--topbar-height);
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    z-index: 90;
    flex-shrink: 0;
}

.menu-toggle-btn {
    display: none;
    font-size: 1.25rem;
    color: var(--text-primary);
    cursor: pointer;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
}

.search-container {
    position: relative;
    width: 420px;
    max-width: 100%;
}

.search-container i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    font-size: 0.95rem;
    pointer-events: none;
}

.search-container input {
    width: 100%;
    height: 42px;
    padding: 0 16px 0 46px;
    border-radius: var(--border-radius-lg);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.9rem;
    transition: all var(--transition-fast);
}

.search-container input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.quick-links {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Button UI */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.875rem;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    border: 1px solid transparent;
    transition: all var(--transition-fast);
}

.btn-primary {
    background-color: var(--primary-color);
    color: #ffffff;
}
.btn-primary:hover {
    background-color: var(--primary-hover);
    box-shadow: 0 4px 12px var(--primary-glow);
}

.btn-secondary {
    background-color: var(--bg-card);
    color: var(--text-primary);
    border-color: var(--border-color);
}
.btn-secondary:hover {
    background-color: var(--bg-primary);
    border-color: var(--primary-color);
}

.btn-block {
    display: flex;
    justify-content: center;
    width: 100%;
}

.btn-close {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 1.25rem;
    cursor: pointer;
    padding: 4px;
    transition: color var(--transition-fast);
}
.btn-close:hover {
    color: var(--danger);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    pointer-events: none;
}

/* Content Wrapper */
.content-wrapper {
    flex-grow: 1;
    overflow-y: auto;
    padding: 40px 32px;
    position: relative;
}

/* Section visibility and fade-in animations */
.content-section {
    max-width: 960px;
    margin: 0 auto;
    animation: fadeIn var(--transition-slow);
}

.content-section.hidden {
    display: none !important;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to { opacity: 1; transform: translateY(0); }
}

/* Markdown formatting overrides for premium look */
.content-section h1 {
    font-family: var(--font-heading);
    font-size: 2.25rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 24px;
    line-height: 1.2;
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.content-section h1 i {
    color: var(--primary-color);
}

.content-section h2 {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 40px;
    margin-bottom: 18px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.content-section h2 i {
    color: var(--primary-color);
    font-size: 1.3rem;
}

.content-section h3 {
    font-family: var(--font-heading);
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-top: 30px;
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.content-section h3 i {
    color: var(--primary-color);
    font-size: 1.05rem;
}

.content-section h4 {
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-top: 20px;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.content-section p {
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.content-section ul, .content-section ol {
    margin-bottom: 24px;
    padding-left: 24px;
    color: var(--text-secondary);
}

.content-section li {
    margin-bottom: 6px;
}

.content-section hr {
    display: none;
}

.content-section a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition-fast);
}

.content-section a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Tables styling */
.content-section table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    margin: 24px 0;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    overflow: hidden;
    font-size: 0.95rem;
}

.content-section th {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    font-weight: 600;
    padding: 14px 16px;
    text-align: left;
    border-bottom: 2px solid var(--border-color);
}

.content-section td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
    background-color: var(--bg-card);
}

.content-section tr:last-child td {
    border-bottom: none;
}

.content-section tr:nth-child(even) td {
    background-color: rgba(0,0,0,0.02);
}

/* Table alternate row background for dark theme removed */

/* Code highlight */
.content-section pre {
    background-color: #0f172a;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 16px;
    overflow-x: auto;
    margin-bottom: 24px;
}

.content-section code {
    font-family: 'SFMono-Regular', Consolas, 'Liberation Mono', Menlo, monospace;
    font-size: 0.875rem;
    padding: 3px 6px;
    border-radius: 4px;
    background-color: var(--bg-secondary);
    color: var(--primary-color);
}

.content-section pre code {
    padding: 0;
    border-radius: 0;
    background-color: transparent;
    color: #f8fafc;
}

/* Alert Boxes (parsed blockquotes) */
.alert-box {
    margin: 24px 0;
    padding: 16px 20px;
    border-radius: var(--border-radius-md);
    border: 1px solid transparent;
    font-size: 0.95rem;
}

.alert-box p {
    margin: 0;
}

.alert-box i {
    margin-right: 8px;
    font-size: 1.1rem;
    vertical-align: middle;
}

.alert-default {
    background-color: var(--bg-secondary);
    border-color: var(--border-color);
    color: var(--text-primary);
}

.alert-warning {
    background-color: var(--warning-bg);
    border-color: var(--warning-border);
    color: var(--warning);
}

.alert-important {
    background-color: var(--info-bg);
    border-color: var(--info-border);
    color: var(--info);
}

.alert-tip {
    background-color: var(--success-bg);
    border-color: var(--success-border);
    color: var(--success);
}

.alert-note {
    background-color: var(--note-bg);
    border-color: var(--note-border);
    color: var(--text-primary);
}

/* SVG Vector graphic styling */
.content-section svg:not(.katex *), .content-section img:not([role="math"]) {
    display: block;
    margin: 30px auto;
    width: 100%;
    max-width: 100%;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 16px;
    box-shadow: none;
    transition: transform var(--transition-normal);
}

.content-section svg:not(.katex *):hover, .content-section img:not([role="math"]):hover {
    transform: scale(1.01);
}

/* Inline and block math images styling */
.content-section img[role="math"] {
    display: inline-block;
    vertical-align: middle;
    margin: 0;
    padding: 0;
    background-color: transparent !important;
    border: none !important;
    border-radius: 0 !important;
    box-shadow: none !important;
    transform: none !important;
    transition: none !important;
}

/* KaTeX custom sizing block override */
.katex-display {
    padding: 12px 0;
    background-color: transparent;
    border-radius: 0;
    border: none;
    margin: 16px 0 !important;
    overflow: visible !important;
}

/* Flatten KaTeX display blocks in tables so they don't break cell layout */
.content-section td .katex-display,
.content-section th .katex-display {
    background-color: transparent !important;
    border: none !important;
    padding: 0 !important;
    margin: 4px 0 !important;
    box-shadow: none !important;
    display: block !important;
    overflow: visible !important;
}


/* Section Cards */
.section-card {
    padding: 30px;
    border-radius: var(--border-radius-lg);
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.04);
    margin-bottom: 30px;
}

/* Glassmorphism effects for all panels and cards */
.section-card,
.calculator-sidebar-card,
.calculator-main-card,
.quiz-card,
.mode-select-card,
.quiz-question-card,
.result-card,
.phasor-left-card,
.phasor-right-card,
.metric-card {
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid rgba(255, 255, 255, 0.45) !important;
}

.hero-card {
    background: linear-gradient(135deg, var(--bg-card) 0%, rgba(22, 155, 98, 0.05) 100%);
    border-left: 6px solid var(--primary-color);
}

/* Interactive Calculator Styles */
.calculator-grid {
    display: grid;
    grid-template-columns: 280px 1fr;
    gap: 30px;
    align-items: start;
    margin-top: 30px;
}

.calculator-sidebar-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 20px;
    position: sticky;
    top: 20px;
}

.calculator-sidebar-card h3 {
    margin-top: 0;
    margin-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    font-size: 1.1rem;
}

.calc-selector-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.calc-sel-item {
    padding: 10px 14px;
    border-radius: var(--border-radius-md);
    font-size: 0.875rem;
    color: var(--text-secondary);
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.calc-sel-item:hover {
    background-color: var(--bg-card);
    color: var(--text-primary);
}

.calc-sel-item.active {
    background-color: var(--primary-color);
    color: #ffffff;
    font-weight: 600;
}

.calculator-main-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 30px;
    box-shadow: var(--shadow-md);
}

.calc-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.calc-desc {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.calc-formula-display {
    padding: 16px;
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-color);
    text-align: center;
    margin-bottom: 24px;
    font-size: 1.15rem;
}

.calc-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-primary);
}

.form-group input, .form-group select {
    height: 42px;
    padding: 0 14px;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: all var(--transition-fast);
}

.form-group input:focus, .form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-glow);
}

.calc-result-box {
    margin-top: 30px;
    padding: 20px;
    border-radius: var(--border-radius-md);
    background-color: var(--success-bg);
    border: 1px solid var(--success-border);
    color: var(--text-primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    text-align: center;
    animation: pulseGently 2s infinite;
}

.calc-result-box.error-box {
    background-color: var(--danger-bg);
    border-color: var(--danger-border);
    color: var(--danger);
}

.calc-result-value {
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--success);
}
.calc-result-box.error-box .calc-result-value {
    color: var(--danger);
    font-size: 1.25rem;
}

.calc-variables-list {
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.calc-variables-list strong {
    color: var(--text-primary);
}

/* Interactive Quiz Styles */
.quiz-modes-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-top: 30px;
}

.quiz-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-md);
}

.mode-select-card {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 200px;
    transition: transform var(--transition-fast), border-color var(--transition-fast);
}

.mode-select-card:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
}

.mode-select-card h3 {
    margin-top: 0;
    font-size: 1.25rem;
    color: var(--text-primary);
}

.mode-select-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 20px;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 24px;
}

.quiz-progress-container {
    flex-grow: 1;
    margin-right: 20px;
}

.quiz-progress-text {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    display: block;
    margin-bottom: 6px;
}

.quiz-progress-bar {
    height: 8px;
    background-color: var(--bg-secondary);
    border-radius: 4px;
    overflow: hidden;
}

.quiz-progress-fill {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 4px;
    transition: width var(--transition-normal);
}

.btn-icon-only {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.btn-icon-only:hover, .btn-icon-only.active {
    border-color: var(--accent-color);
    color: var(--accent-color);
    background-color: var(--warning-bg);
}

.quiz-question-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 30px;
    box-shadow: var(--shadow-md);
    margin-bottom: 24px;
    position: relative;
}

.quiz-phase-badge {
    position: absolute;
    top: 20px;
    right: 24px;
    font-size: 0.725rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.8px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 4px 10px;
    border-radius: 20px;
    color: var(--primary-color);
}

.quiz-question-text {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-top: 15px;
    margin-bottom: 24px;
    line-height: 1.4;
}

.quiz-choices-container {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 24px;
}

.choice-option {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 18px;
    border-radius: var(--border-radius-md);
    border: 1px solid var(--border-color);
    background-color: var(--bg-secondary);
    cursor: pointer;
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.choice-option:hover {
    border-color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.02);
}

.choice-option.selected {
    border-color: var(--primary-color);
    background-color: var(--primary-glow);
    box-shadow: 0 0 0 1px var(--primary-color);
}

.choice-option.correct {
    border-color: var(--success);
    background-color: var(--success-bg);
}

.choice-option.incorrect {
    border-color: var(--danger);
    background-color: var(--danger-bg);
}

.choice-letter {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-secondary);
}

.choice-option.selected .choice-letter {
    background-color: var(--primary-color);
    border-color: var(--primary-color);
    color: #ffffff;
}

.choice-option.correct .choice-letter {
    background-color: var(--success);
    border-color: var(--success);
    color: #ffffff;
}

.choice-option.incorrect .choice-letter {
    background-color: var(--danger);
    border-color: var(--danger);
    color: #ffffff;
}

.choice-text {
    flex-grow: 1;
}

.quiz-feedback-box {
    margin-top: 24px;
    padding: 20px;
    border-radius: var(--border-radius-md);
    animation: slideUp var(--transition-normal);
}

.quiz-feedback-box.correct-box {
    background-color: var(--success-bg);
    border: 1px solid var(--success-border);
}
.quiz-feedback-box.incorrect-box {
    background-color: var(--danger-bg);
    border: 1px solid var(--danger-border);
}

#quiz-feedback-header {
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 10px;
}
.correct-box #quiz-feedback-header { color: var(--success); }
.incorrect-box #quiz-feedback-header { color: var(--danger); }

/* Accordion Component */
.worked-solution-accordion {
    margin-top: 15px;
    border-top: 1px solid var(--border-color);
    padding-top: 15px;
}

.accordion-trigger {
    background: transparent;
    border: none;
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-family: var(--font-body);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 6px 0;
}

.accordion-trigger:hover {
    color: var(--text-primary);
}

.accordion-arrow {
    font-size: 0.8rem;
    transition: transform var(--transition-fast);
}

.accordion-trigger.active .accordion-arrow {
    transform: rotate(180deg);
}

.accordion-content {
    max-height: 0;
    overflow: hidden;
    transition: max-height var(--transition-normal) ease-out, padding var(--transition-normal);
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.accordion-content.open {
    max-height: 500px;
    padding-top: 10px;
    overflow-y: auto;
}

.quiz-nav-bar {
    display: flex;
    align-items: center;
}

/* Results Screen */
.score-display {
    font-size: 3rem;
    font-weight: 800;
    color: var(--primary-color);
    margin: 20px 0;
    line-height: 1;
}

.score-percent {
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-top: 4px;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.result-card {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.result-card h4 {
    margin-top: 0;
    color: var(--text-primary);
    font-size: 0.95rem;
}

.result-bar-wrapper {
    height: 10px;
    background-color: var(--bg-secondary);
    border-radius: 5px;
    overflow: hidden;
}

.result-bar-fill {
    height: 100%;
    background-color: var(--primary-color);
    border-radius: 5px;
    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
}

.result-card span {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.quiz-flagged-review {
    margin-bottom: 30px;
}

.quiz-flagged-review h3 {
    margin-top: 0;
    font-size: 1.15rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 8px;
    margin-bottom: 16px;
}

.flagged-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.flagged-item {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 14px 18px;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.flagged-item:hover {
    border-color: var(--accent-color);
    background-color: var(--bg-card);
}

/* Search results listing */
.search-results-panel {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 24px;
    margin-bottom: 30px;
    box-shadow: var(--shadow-md);
    animation: slideDown var(--transition-normal);
}

.search-results-panel.hidden {
    display: none !important;
}

.search-results-panel .panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 10px;
    margin-bottom: 16px;
}

.search-results-panel h3 {
    margin: 0;
    font-size: 1.15rem;
}

.search-results-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
    max-height: 400px;
    overflow-y: auto;
}

.search-result-item {
    padding: 12px 16px;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.search-result-item:hover {
    border-color: var(--primary-color);
    background-color: var(--bg-primary);
}

.search-result-item h4 {
    margin: 0 0 4px 0;
    color: var(--primary-color);
    font-size: 0.95rem;
}

.search-result-item p {
    margin: 0;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* Animations */
@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0.4); }
    70% { box-shadow: 0 0 0 10px rgba(59, 130, 246, 0); }
    100% { box-shadow: 0 0 0 0 rgba(59, 130, 246, 0); }
}

@keyframes pulseGently {
    0% { transform: scale(1); }
    50% { transform: scale(1.005); box-shadow: 0 4px 10px var(--primary-glow); }
    100% { transform: scale(1); }
}

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

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

/* Mobile Responsiveness Rules */
@media (max-width: 1024px) {
    .calculator-grid {
        grid-template-columns: 1fr;
    }
    .calculator-sidebar-card {
        position: static;
    }
}

@media (max-width: 768px) {
    :root {
        --sidebar-width: 250px;
    }
    
    .menu-toggle-btn {
        display: flex;
    }
    
    .sidebar {
        position: absolute;
        top: 0;
        left: 0;
        bottom: 0;
        transform: translateX(-100%);
        box-shadow: var(--shadow-lg);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .top-bar {
        padding: 0 20px;
    }
    
    .search-container {
        width: 200px;
    }
    
    .content-wrapper {
        padding: 24px 20px;
    }
    
    .content-section h1 {
        font-size: 1.75rem;
    }
    .content-section h2 {
        font-size: 1.3rem;
    }
    
    .top-bar .quick-links span {
        display: none;
    }
}

/* Floating Scientific Calculator Styling */
.floating-calc-panel {
    position: fixed;
    bottom: 85px;
    right: 24px;
    z-index: 999;
    width: 320px;
    background: rgba(255, 255, 255, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-radius: 16px;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s linear;
}

.floating-calc-panel.hidden {
    transform: scale(0.9) translateY(20px);
    opacity: 0;
    pointer-events: none;
}

.floating-calc-header {
    padding: 12px 16px;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 600;
    cursor: move;
    user-select: none;
    font-size: 0.9rem;
    color: var(--text-primary);
    border-top-left-radius: 16px;
    border-top-right-radius: 16px;
}

.floating-calc-header span i {
    color: var(--primary-color);
    margin-right: 6px;
}

.calc-header-controls {
    display: flex;
    gap: 8px;
    align-items: center;
}

.calc-ctrl-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    font-size: 0.85rem;
    border-radius: 4px;
    transition: background var(--transition-fast), color var(--transition-fast);
    display: flex;
    align-items: center;
    justify-content: center;
    width: 22px;
    height: 22px;
}

.calc-ctrl-btn:hover {
    background: rgba(0, 0, 0, 0.05);
    color: var(--text-primary);
}

#floating-calc-close:hover {
    background: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.floating-calc-body {
    padding: 16px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.calc-screen-wrapper {
    background: #0f172a;
    color: #f8fafc;
    border-radius: 10px;
    padding: 12px;
    font-family: 'Consolas', 'Courier New', Courier, monospace;
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    min-height: 72px;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.3);
}

.calc-screen-expr {
    font-size: 0.8rem;
    color: #94a3b8;
    min-height: 1.2em;
    word-wrap: break-word;
    text-align: right;
    width: 100%;
    overflow-x: auto;
    white-space: nowrap;
}

.calc-screen-display {
    font-size: 1.5rem;
    font-weight: 600;
    overflow-x: auto;
    max-width: 100%;
    white-space: nowrap;
    width: 100%;
    text-align: right;
}

.calc-mode-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.calc-badge {
    font-size: 0.7rem;
    font-weight: 700;
    background: rgba(59, 130, 246, 0.1);
    color: var(--primary-color);
    padding: 2px 6px;
    border-radius: 4px;
    letter-spacing: 0.5px;
}

.calc-toggle-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    font-size: 0.7rem;
    font-weight: 600;
    padding: 2px 8px;
    border-radius: 4px;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.calc-toggle-btn:hover {
    border-color: var(--primary-color);
    color: var(--primary-color);
}

.calc-keyboard {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 6px;
}

.calc-btn {
    border: none;
    border-radius: 8px;
    padding: 10px 0;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.08s ease, background 0.15s ease;
    outline: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: var(--font-heading);
}

.calc-btn:active {
    transform: scale(0.92);
}

.btn-num {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-num:hover {
    background: var(--bg-secondary);
}

.btn-op {
    background: rgba(59, 130, 246, 0.08);
    color: var(--primary-color);
    font-size: 1rem;
}

.btn-op:hover {
    background: rgba(59, 130, 246, 0.15);
}

.btn-sci {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-size: 0.8rem;
    font-weight: 500;
}

.btn-sci:hover {
    background: var(--border-color);
    color: var(--text-primary);
}

.btn-action {
    background: rgba(239, 68, 68, 0.08);
    color: #ef4444;
}

.btn-action:hover {
    background: rgba(239, 68, 68, 0.15);
}

.btn-equal {
    background: var(--primary-color);
    color: #ffffff;
}

.btn-equal:hover {
    background: var(--primary-hover);
}

/* Floating Action Button (FAB) */
.floating-calc-fab-btn {
    position: fixed;
    bottom: 24px;
    right: 24px;
    z-index: 998;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: var(--primary-color);
    color: #fff;
    border: none;
    font-size: 1.3rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 4px 15px rgba(59, 130, 246, 0.35);
    transition: transform 0.2s cubic-bezier(0.175, 0.885, 0.32, 1.275), box-shadow 0.2s ease;
}

.floating-calc-fab-btn:hover {
    transform: scale(1.08) rotate(8deg);
    box-shadow: 0 6px 18px rgba(59, 130, 246, 0.45);
}

.floating-calc-fab-btn:active {
    transform: scale(0.95);
}

@media (max-width: 480px) {
    .floating-calc-panel {
        width: calc(100vw - 32px);
        right: 16px;
        bottom: 80px;
        left: 16px;
    }
    
    .floating-calc-panel.hidden {
        transform: translateY(120%);
        opacity: 0;
    }
    
    .floating-calc-fab-btn {
        bottom: 16px;
        right: 16px;
        width: 46px;
        height: 46px;
        font-size: 1.2rem;
    }
}

/* ==========================================================================
   INTERACTIVE PHASOR & VECTORIAL GIZMO STYLES
   ========================================================================== */
.phasor-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 30px;
    align-items: start;
    margin-top: 30px;
}

.phasor-left-card,
.phasor-right-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 25px;
    box-shadow: var(--shadow-sm);
    display: flex;
    flex-direction: column;
}

/* Tabs */
.phasor-tab-container {
    display: flex;
    background-color: var(--bg-secondary);
    padding: 4px;
    border-radius: var(--border-radius-md);
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

.phasor-tab-btn {
    flex: 1;
    padding: 10px 16px;
    border: none;
    background: none;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-secondary);
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    transition: all var(--transition-fast);
    font-family: 'Outfit', sans-serif;
}

.phasor-tab-btn.active {
    background-color: var(--bg-card);
    color: var(--primary-color);
    box-shadow: var(--shadow-sm);
}

/* Canvas Wrappers */
.phasor-canvas-wrapper,
.waveform-canvas-wrapper {
    width: 100%;
    aspect-ratio: 1;
    max-width: 400px;
    margin: 0 auto;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-md);
    padding: 15px;
    display: flex;
    justify-content: center;
    align-items: center;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.02);
    position: relative;
    overflow: hidden;
}

.waveform-canvas-wrapper {
    aspect-ratio: 16/9;
    padding: 10px;
}

/* SVG Stylings */
#phasor-svg,
#waveform-svg {
    width: 100%;
    height: 100%;
    user-select: none;
}

/* Sliders */
.phasor-sliders-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-top: 25px;
    padding-bottom: 25px;
    border-bottom: 1px solid var(--border-color);
}

.slider-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.slider-header {
    display: flex;
    justify-content: space-between;
    font-weight: 600;
    font-size: 0.95rem;
}

.slider-label {
    color: var(--text-secondary);
}

.slider-value {
    color: var(--primary-color);
    font-family: 'Outfit', monospace;
}

/* Custom Sliders */
.slider-group input[type="range"] {
    -webkit-appearance: none;
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: var(--border-color);
    outline: none;
    transition: background var(--transition-fast);
}

.slider-group input[type="range"]::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: var(--primary-color);
    cursor: pointer;
    box-shadow: 0 0 10px rgba(59, 130, 246, 0.5);
    transition: transform var(--transition-fast);
}

.slider-group input[type="range"]::-webkit-slider-thumb:hover {
    transform: scale(1.15);
}

/* Presets */
.phasor-presets-container {
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.phasor-presets-container h4 {
    margin: 0 0 12px 0;
    font-size: 1rem;
    color: var(--text-main);
}

.preset-btns {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

/* Metrics Dashboard */
.phasor-metrics-container {
    margin-top: 25px;
}

.phasor-metrics-container h4 {
    margin: 0 0 15px 0;
    font-size: 1rem;
    color: var(--text-main);
}

.metrics-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 15px;
}

.metric-card {
    padding: 16px;
    border-radius: var(--border-radius-md);
    background-color: var(--bg-secondary);
    border: 1px dashed var(--border-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: all var(--transition-fast);
}

.metric-card:hover {
    transform: translateY(-2px);
    border-color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.02);
}

.metric-title {
    font-size: 0.825rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 8px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.metric-value {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-main);
    font-family: 'Outfit', sans-serif;
}

.metric-eqn {
    font-size: 0.775rem;
    color: var(--text-secondary);
    margin-top: 8px;
    font-family: monospace;
}

/* Responsive styles */
@media (max-width: 992px) {
    .phasor-grid {
        grid-template-columns: 1fr;
    }
    .phasor-left-card {
        order: 1;
    }
    .phasor-right-card {
        order: 2;
    }
}