/* --- Design System / Variables --- */
:root {
    --bg-main: #0a0813;
    --bg-card: rgba(22, 18, 38, 0.45);
    --bg-card-hover: rgba(30, 25, 52, 0.6);
    --border-color: rgba(255, 255, 255, 0.06);
    --border-color-hover: rgba(255, 255, 255, 0.12);
    
    --primary: #6c5ce7;
    --primary-light: #8e80f9;
    --primary-glow: rgba(108, 92, 231, 0.15);
    
    --text-main: #ffffff;
    --text-muted: #9590ad;
    --text-link: #a29bfe;
    
    --color-green: #00b894;
    --color-green-glow: rgba(0, 184, 148, 0.12);
    --color-red: #ff7675;
    --color-red-glow: rgba(255, 118, 117, 0.12);
    --color-yellow: #fdcb6e;
    --color-yellow-glow: rgba(253, 203, 110, 0.12);
    --color-blue: #0984e3;
    --color-blue-glow: rgba(9, 132, 227, 0.12);
    --color-orange: #e17055;
    
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    --sidebar-width: 260px;
    --header-height: 80px;
    --border-radius: 16px;
    --shadow-main: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
    --transition-speed: 0.25s;
}

/* --- Base Styles & Reset --- */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    scrollbar-width: thin;
    scrollbar-color: var(--primary) var(--bg-main);
}

body {
    background-color: var(--bg-main);
    background-image: 
        radial-gradient(at 10% 10%, rgba(108, 92, 231, 0.08) 0px, transparent 50%),
        radial-gradient(at 90% 90%, rgba(9, 132, 227, 0.06) 0px, transparent 50%);
    color: var(--text-main);
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.6;
    overflow-x: hidden;
    height: 100vh;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}
::-webkit-scrollbar-track {
    background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
    background: var(--border-color-hover);
    border-radius: 10px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

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

/* --- Sidebar --- */
.sidebar {
    width: var(--sidebar-width);
    background-color: #0d0a1a;
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    padding: 24px 16px;
    z-index: 10;
    flex-shrink: 0;
}

.sidebar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 8px 12px 24px 12px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.brand-icon {
    font-size: 28px;
    background: linear-gradient(135deg, var(--primary), var(--text-link));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.brand-text h2 {
    font-family: var(--font-heading);
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 0.5px;
    line-height: 1.2;
}

.brand-text span {
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 1.5px;
}

.sidebar-nav {
    display: flex;
    flex-direction: column;
    gap: 8px;
    flex-grow: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    color: var(--text-muted);
    text-decoration: none;
    border-radius: 12px;
    font-weight: 500;
    font-size: 14px;
    transition: all var(--transition-speed) ease;
    position: relative;
}

.nav-item i {
    font-size: 16px;
    width: 20px;
    text-align: center;
}

.nav-item:hover {
    color: var(--text-main);
    background-color: rgba(255, 255, 255, 0.03);
}

.nav-item.active {
    color: var(--text-main);
    background-color: var(--primary-glow);
    border: 1px solid rgba(108, 92, 231, 0.2);
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 25%;
    height: 50%;
    width: 4px;
    background-color: var(--primary);
    border-radius: 0 4px 4px 0;
}

.nav-item .badge {
    margin-left: auto;
    background-color: var(--color-red);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 10px;
}

.sidebar-footer {
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

.quick-stats {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 12px;
    border-radius: 12px;
}

.stat-row {
    display: flex;
    justify-content: space-between;
    font-size: 12px;
    margin-bottom: 6px;
}

.stat-row span {
    color: var(--text-muted);
}

.progress-bar-container {
    height: 6px;
    background-color: rgba(255, 255, 255, 0.05);
    border-radius: 3px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), var(--color-blue));
    border-radius: 3px;
    transition: width 0.5s ease-in-out;
}

/* --- Main Content --- */
.main-content {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    height: 100vh;
}

/* --- Header --- */
.app-header {
    height: var(--header-height);
    border-bottom: 1px solid var(--border-color);
    padding: 0 32px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    background-color: rgba(10, 8, 19, 0.4);
    backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 5;
    flex-shrink: 0;
}

.app-header h1 {
    font-family: var(--font-heading);
    font-size: 22px;
    font-weight: 700;
}

.app-header .subtitle {
    font-size: 12px;
    color: var(--text-muted);
    margin-top: 2px;
}

.header-right {
    display: flex;
    gap: 24px;
}

.quick-metric {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: 12px;
}

.quick-metric i {
    font-size: 18px;
}

.metric-label {
    display: block;
    font-size: 10px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.metric-value {
    display: block;
    font-size: 13px;
    font-weight: 600;
}

/* Text Glow Helpers */
.text-orange { color: var(--color-orange); }
.text-green { color: var(--color-green); }
.text-blue { color: var(--color-blue); }
.text-yellow { color: var(--color-yellow); }

/* --- Tab Transitions --- */
.tab-content {
    display: none;
    padding: 32px;
    flex-grow: 1;
    animation: fadeIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

/* --- Glassmorphic Card Styling --- */
.glassmorphic {
    background: var(--bg-card);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-main);
    transition: border-color var(--transition-speed) ease, background-color var(--transition-speed) ease;
}

.glassmorphic:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-color-hover);
}

/* --- Dashboard Specifics --- */
.dashboard-grid {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.card-hero {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 32px;
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.2) 0%, rgba(9, 132, 227, 0.1) 100%);
    border: 1px solid rgba(108, 92, 231, 0.3);
}

.card-hero-content {
    max-width: 70%;
}

.card-hero-content h3 {
    font-family: var(--font-heading);
    font-size: 26px;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(90deg, #ffffff, var(--text-link));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.card-hero-content p {
    color: var(--text-muted);
    font-size: 14px;
    margin-bottom: 20px;
    line-height: 1.5;
}

.hero-actions {
    display: flex;
    gap: 12px;
}

.card-hero-illustration {
    font-size: 72px;
    margin-right: 20px;
    opacity: 0.85;
    animation: float 4s ease-in-out infinite;
}

.hero-lightning {
    background: linear-gradient(135deg, var(--color-yellow), var(--color-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    filter: drop-shadow(0 0 15px rgba(253, 203, 110, 0.4));
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-10px); }
}

.stats-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
}

.stat-card {
    display: flex;
    align-items: center;
    gap: 20px;
    padding: 24px;
}

.stat-card-icon {
    width: 54px;
    height: 54px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.bg-blue-glow {
    background: var(--color-blue-glow);
    color: var(--color-blue);
    border: 1px solid rgba(9, 132, 227, 0.2);
}

.bg-green-glow {
    background: var(--color-green-glow);
    color: var(--color-green);
    border: 1px solid rgba(0, 184, 148, 0.2);
}

.bg-purple-glow {
    background: var(--primary-glow);
    color: var(--primary-light);
    border: 1px solid rgba(108, 92, 231, 0.2);
}

.stat-card-info h3 {
    font-size: 12px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-card-info .number {
    display: block;
    font-family: var(--font-heading);
    font-size: 28px;
    font-weight: 700;
    line-height: 1.2;
    margin: 2px 0;
}

.stat-card-info .subtext {
    font-size: 11px;
    color: var(--text-muted);
}

.card {
    padding: 24px;
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.card-header h3 {
    font-family: var(--font-heading);
    font-size: 18px;
    font-weight: 600;
}

.card-header-action {
    font-size: 12px;
    color: var(--primary-light);
    background: var(--primary-glow);
    padding: 4px 10px;
    border-radius: 20px;
    font-weight: 500;
}

.topic-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

.topic-progress-card {
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 12px;
    transition: transform 0.2s ease;
}

.topic-progress-card:hover {
    transform: translateY(-2px);
    border-color: var(--border-color-hover);
}

.topic-card-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 10px;
}

.topic-name {
    font-weight: 600;
    font-size: 14px;
}

.topic-percentage {
    font-size: 12px;
    color: var(--text-muted);
}

.topic-stat-subtext {
    display: flex;
    justify-content: space-between;
    font-size: 11px;
    color: var(--text-muted);
    margin-top: 6px;
}

/* --- Buttons --- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: 12px;
    font-family: var(--font-body);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    outline: none;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 11px;
    border-radius: 8px;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 15px;
}

.btn-primary {
    background-color: var(--primary);
    color: #fff;
    box-shadow: 0 4px 12px rgba(108, 92, 231, 0.3);
}

.btn-primary:hover {
    background-color: var(--primary-light);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: rgba(255, 255, 255, 0.05);
    color: var(--text-main);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.btn-success {
    background-color: var(--color-green);
    color: #fff;
    box-shadow: 0 4px 12px rgba(0, 184, 148, 0.3);
}

.btn-success:hover {
    opacity: 0.9;
}

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

/* --- Learn Hub --- */
.learn-container {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.topic-selector-strip {
    display: flex;
    gap: 10px;
    overflow-x: auto;
    padding-bottom: 8px;
}

.topic-selector-strip::-webkit-scrollbar {
    height: 4px;
}

.topic-chip {
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    color: var(--text-muted);
    cursor: pointer;
    font-size: 12px;
    font-weight: 500;
    white-space: nowrap;
    transition: all 0.2s ease;
}

.topic-chip:hover, .topic-chip.active {
    color: #fff;
    background-color: var(--primary);
    border-color: var(--primary-light);
}

.concept-card {
    padding: 32px;
}

.concept-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 20px;
    margin-bottom: 24px;
}

.topic-badge {
    display: inline-block;
    padding: 3px 8px;
    background: var(--primary-glow);
    border: 1px solid rgba(108, 92, 231, 0.3);
    color: var(--text-link);
    font-size: 11px;
    font-weight: 600;
    border-radius: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.pattern-badge {
    display: inline-block;
    padding: 3px 8px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid rgba(255, 255, 255, 0.1);
    color: var(--text-muted);
    font-size: 11px;
    font-weight: 500;
    border-radius: 6px;
    margin-left: 8px;
}

.concept-title-group h2 {
    font-family: var(--font-heading);
    font-size: 24px;
    font-weight: 700;
}

.concept-body {
    display: flex;
    flex-direction: column;
    gap: 28px;
}

.concept-section h3 {
    font-family: var(--font-heading);
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-link);
}

.concept-section p {
    color: var(--text-muted);
    font-size: 14px;
    line-height: 1.6;
}

.formula-box {
    background: rgba(108, 92, 231, 0.05);
    border: 1px solid rgba(108, 92, 231, 0.2);
    border-radius: 12px;
    padding: 20px;
}

.formula-box h3 {
    font-size: 14px;
    color: var(--text-link);
    margin-bottom: 12px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.formula-list {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.formula-item {
    font-family: 'Courier New', Courier, monospace;
    background: rgba(0, 0, 0, 0.2);
    padding: 10px 14px;
    border-radius: 6px;
    border-left: 3px solid var(--primary);
    font-size: 13px;
    color: #fff;
}

.shortcut-tip {
    background: rgba(253, 203, 110, 0.06);
    border: 1px solid rgba(253, 203, 110, 0.2);
    padding: 16px;
    border-radius: 12px;
    font-size: 13px;
    line-height: 1.5;
}

.example-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.example-item {
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 12px;
}

.example-q {
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 8px;
}

.example-a {
    color: var(--text-muted);
    font-size: 13px;
    white-space: pre-line;
    border-top: 1px solid var(--border-color);
    padding-top: 8px;
    margin-top: 8px;
}

/* --- Practice Arena --- */
.practice-layout {
    display: flex;
    gap: 24px;
}

.practice-filters {
    width: 220px;
    flex-shrink: 0;
    padding: 20px;
    height: fit-content;
}

.practice-filters h3 {
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.topic-filter-list {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.filter-btn {
    text-align: left;
    background: none;
    border: none;
    color: var(--text-muted);
    padding: 8px 12px;
    border-radius: 8px;
    cursor: pointer;
    font-size: 12px;
    font-weight: 500;
    transition: all 0.2s ease;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.filter-btn:hover {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-main);
}

.filter-btn.active {
    background: var(--primary-glow);
    color: var(--text-link);
    border: 1px solid rgba(108, 92, 231, 0.2);
}

.practice-workspace {
    flex-grow: 1;
}

.question-card {
    padding: 32px;
}

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

.question-timer {
    display: flex;
    align-items: center;
    gap: 8px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 10px;
    font-size: 12px;
    color: var(--text-muted);
}

.question-timer i {
    animation: heartbeat 1.5s infinite;
}

@keyframes heartbeat {
    0%, 100% { transform: scale(1); }
    50% { transform: scale(1.15); }
}

.question-body {
    font-size: 16px;
    font-weight: 500;
    margin-bottom: 28px;
    line-height: 1.6;
}

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

.option-btn {
    width: 100%;
    text-align: left;
    padding: 16px 20px;
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    color: var(--text-main);
    cursor: pointer;
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 500;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

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

.option-btn.selected {
    background-color: var(--primary-glow);
    border-color: var(--primary);
}

.option-btn.correct {
    background-color: var(--color-green-glow);
    border-color: var(--color-green);
    color: #fff;
}

.option-btn.incorrect {
    background-color: var(--color-red-glow);
    border-color: var(--color-red);
    color: #fff;
}

.option-btn i {
    font-size: 14px;
}

/* Explanation Panel */
.explanation-card {
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    margin-top: 24px;
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.explanation-header {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 12px;
}

.explanation-body {
    font-size: 13px;
    color: var(--text-muted);
    white-space: pre-line;
    margin-bottom: 16px;
}

.shortcut-box {
    background: rgba(253, 203, 110, 0.05);
    border-left: 4px solid var(--color-yellow);
    padding: 12px 16px;
    border-radius: 0 8px 8px 0;
    margin-bottom: 16px;
}

.shortcut-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 600;
    font-size: 12px;
    color: var(--color-yellow);
    margin-bottom: 4px;
}

.shortcut-box p {
    font-size: 12px;
    color: var(--text-main);
}

.mistake-prompt {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 14px;
    margin-top: 14px;
    font-size: 12px;
    color: var(--text-muted);
}

.question-footer {
    display: flex;
    justify-content: flex-end;
    margin-top: 24px;
}

.navigation-buttons {
    display: flex;
    gap: 12px;
}

/* --- Mistake Bank --- */
.mistake-container {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

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

.mistake-info-box {
    display: flex;
    align-items: center;
    gap: 16px;
}

.info-icon {
    font-size: 32px;
    color: var(--color-red);
}

.mistake-info-box h3 {
    font-family: var(--font-heading);
    font-size: 18px;
    font-weight: 600;
}

.mistake-info-box p {
    font-size: 12px;
    color: var(--text-muted);
}

.mistake-filters-bar {
    display: flex;
    gap: 20px;
    padding: 16px 24px;
}

.filter-group {
    display: flex;
    align-items: center;
    gap: 10px;
}

.filter-group label {
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 500;
}

.form-select {
    background-color: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    color: #fff;
    padding: 6px 12px;
    border-radius: 8px;
    font-family: var(--font-body);
    font-size: 12px;
    outline: none;
}

.form-select option {
    background-color: var(--bg-main);
    color: #fff;
}

.mistake-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(360px, 1fr));
    gap: 20px;
}

.mistake-card {
    padding: 20px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}

.mistake-card-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 12px;
}

.mistake-card-body p {
    font-size: 13px;
    font-weight: 500;
    line-height: 1.5;
    margin-bottom: 16px;
}

.mistake-action-row {
    border-top: 1px solid var(--border-color);
    padding-top: 14px;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.mistake-reason-selector {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
}

.mistake-reason-selector label {
    font-size: 10px;
    color: var(--text-muted);
    text-transform: uppercase;
}

.mistake-buttons {
    display: flex;
    justify-content: space-between;
    margin-top: 4px;
}

.btn-danger-text {
    background: none;
    border: none;
    color: var(--color-red);
    cursor: pointer;
    font-size: 12px;
    font-weight: 600;
}

.btn-danger-text:hover {
    text-decoration: underline;
}

/* --- Mock Tests --- */
.mock-config-container {
    max-width: 600px;
    margin: 40px auto;
    padding: 40px;
    text-align: center;
}

.mock-large-icon {
    font-size: 54px;
    color: var(--primary-light);
    margin-bottom: 20px;
}

.mock-config-container h2 {
    font-family: var(--font-heading);
    font-size: 24px;
    font-weight: 700;
    margin-bottom: 8px;
}

.mock-config-container p {
    font-size: 13px;
    color: var(--text-muted);
    margin-bottom: 30px;
}

.mock-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
    text-align: left;
}

.form-row {
    display: flex;
    gap: 20px;
}

.form-col {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-col label {
    font-size: 11px;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.form-col .form-select {
    padding: 10px 14px;
    font-size: 13px;
}

/* Mock test active environment */
.mock-workspace-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
    animation: fadeIn 0.4s ease;
}

.mock-navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px 24px;
}

.mock-nav-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.mock-title {
    font-weight: 700;
    font-family: var(--font-heading);
}

.mock-badge {
    background: rgba(255, 255, 255, 0.05);
    padding: 4px 10px;
    border-radius: 8px;
    font-size: 11px;
    font-weight: 600;
}

.mock-nav-timer {
    display: flex;
    align-items: center;
    gap: 10px;
    background: rgba(255, 118, 117, 0.08);
    border: 1px solid rgba(255, 118, 117, 0.3);
    padding: 8px 16px;
    border-radius: 12px;
    color: var(--color-red);
    font-weight: 700;
    font-size: 16px;
}

.red-glow {
    box-shadow: 0 0 12px rgba(255, 118, 117, 0.2);
}

.mock-question-layout {
    display: flex;
    gap: 20px;
}

.mock-question-layout .question-card {
    flex-grow: 1;
}

.mock-controls {
    display: flex;
    gap: 10px;
    width: 100%;
    justify-content: flex-end;
}

.mock-side-panel {
    width: 240px;
    flex-shrink: 0;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 16px;
    height: fit-content;
}

.mock-side-panel h4 {
    font-size: 13px;
    text-transform: uppercase;
    color: var(--text-muted);
}

.mock-nav-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 8px;
}

.mock-nav-bubble {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.02);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
}

.mock-nav-bubble:hover {
    border-color: var(--border-color-hover);
    background: rgba(255, 255, 255, 0.05);
}

.mock-nav-bubble.answered {
    background-color: var(--primary-glow);
    border-color: var(--primary);
    color: var(--text-link);
}

.mock-nav-bubble.current {
    background-color: #fff;
    color: #000;
    border-color: #fff;
}

.mock-nav-legend {
    display: flex;
    flex-direction: column;
    gap: 8px;
    font-size: 11px;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    padding-top: 12px;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.bubble {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    display: inline-block;
}

.bubble.answered {
    background-color: var(--primary-glow);
    border-color: var(--primary);
}

.bubble.current {
    background-color: #fff;
    border-color: #fff;
}

/* Mock results */
.mock-results-container {
    max-width: 600px;
    margin: 40px auto;
    padding: 40px;
    text-align: center;
    animation: fadeIn 0.4s ease;
}

.trophy-icon {
    font-size: 64px;
    color: var(--color-yellow);
    margin-bottom: 20px;
    filter: drop-shadow(0 0 10px rgba(253, 203, 110, 0.3));
}

.results-score {
    font-family: var(--font-heading);
    font-size: 48px;
    font-weight: 800;
    margin: 12px 0;
}

.results-feedback {
    font-size: 14px;
    color: var(--text-muted);
    margin-bottom: 30px;
}

.results-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 30px;
}

.result-metric-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 16px;
    border-radius: 12px;
    display: flex;
    flex-direction: column;
}

.result-metric-card .label {
    font-size: 10px;
    color: var(--text-muted);
    text-transform: uppercase;
}

.result-metric-card .value {
    font-size: 18px;
    font-weight: 700;
    margin-top: 4px;
}

.results-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
}

/* --- Modals --- */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(0, 0, 0, 0.65);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    animation: fadeIn 0.25s ease;
}

.modal-content {
    width: 600px;
    max-width: 90%;
    max-height: 85vh;
    overflow-y: auto;
    padding: 32px;
    position: relative;
}

.close-btn {
    position: absolute;
    top: 20px;
    right: 20px;
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 28px;
    cursor: pointer;
}

.close-btn:hover {
    color: #fff;
}

.modal-header {
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-family: var(--font-heading);
    font-size: 18px;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    margin-top: 24px;
    padding-top: 16px;
    border-top: 1px solid var(--border-color);
}

/* Responsive Overrides */
@media (max-width: 992px) {
    .sidebar {
        width: 70px;
        padding: 24px 8px;
    }
    .brand-text, .nav-item span, .sidebar-footer {
        display: none;
    }
    .nav-item {
        justify-content: center;
        padding: 12px;
    }
    .app-header {
        padding: 0 20px;
    }
    .tab-content {
        padding: 20px;
    }
    .mock-question-layout {
        flex-direction: column;
    }
    .mock-side-panel {
        width: 100%;
    }
}

/* --- Expanded Formula Card Styles --- */
.formula-card {
    background: rgba(30, 25, 52, 0.3);
    border: 1px solid var(--border-color);
    border-left: 5px solid var(--primary);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 28px;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.15);
}

.formula-card:hover {
    border-color: var(--primary-light);
    border-left-width: 8px;
    background: rgba(30, 25, 52, 0.5);
    box-shadow: 0 8px 25px rgba(108, 92, 231, 0.15);
    transform: translateX(3px);
}

.formula-card-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 18px;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 12px;
}

.formula-number-badge {
    background: linear-gradient(135deg, var(--primary), var(--color-blue));
    color: #ffffff;
    font-size: 11px;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 6px;
    letter-spacing: 0.5px;
    text-transform: uppercase;
}

.formula-name-text {
    font-family: var(--font-heading);
    font-size: 17px;
    font-weight: 700;
    color: #ffffff;
}

.formula-section-block {
    margin-bottom: 16px;
}

.formula-section-block:last-child {
    margin-bottom: 0;
}

.section-label {
    display: block;
    font-size: 10px;
    font-weight: 700;
    letter-spacing: 1.5px;
    margin-bottom: 6px;
    font-family: var(--font-heading);
}

.label-equation {
    color: var(--text-link);
}

.label-clues {
    color: var(--color-yellow);
}

.label-calc {
    color: var(--color-green);
}

.formula-equation {
    font-family: 'Courier New', Courier, monospace;
    background: rgba(0, 0, 0, 0.35);
    padding: 12px 16px;
    border-radius: 8px;
    border-left: 3px solid var(--primary-light);
    font-size: 14.5px;
    color: #ffffff;
    font-weight: 600;
    box-shadow: inset 0 2px 5px rgba(0,0,0,0.2);
}

.formula-clues {
    font-size: 13px;
    color: #dfe6e9;
    background: rgba(253, 203, 110, 0.04);
    border: 1px dashed rgba(253, 203, 110, 0.25);
    padding: 12px 16px;
    border-radius: 8px;
    line-height: 1.5;
}

.formula-calculation {
    background: rgba(0, 184, 148, 0.04);
    border: 1px solid rgba(0, 184, 148, 0.25);
    border-radius: 8px;
    padding: 14px 18px;
    margin-top: 14px;
    animation: slideDown 0.25s ease-out;
}

.formula-calculation-steps {
    font-family: 'Courier New', Courier, monospace;
    font-size: 13px;
    color: #ffffff;
    white-space: pre-line;
    line-height: 1.5;
}

.formula-test-question {
    background: rgba(108, 92, 231, 0.03);
    border: 1px solid rgba(108, 92, 231, 0.15);
    border-radius: 8px;
    padding: 14px 18px;
    font-size: 13.5px;
    color: #ffffff;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 10px;
    line-height: 1.5;
    margin-bottom: 12px;
}

.question-mark-icon {
    color: var(--primary-light);
    font-size: 18px;
}

.toggle-calc-btn {
    margin-top: 4px;
    transition: all 0.2s ease;
}

/* --- Shortcut Rule Visual Enhancements --- */
.shortcut-badge {
    background: linear-gradient(135deg, var(--color-yellow), #e1b12c);
    color: #000000;
    font-size: 10px;
    font-weight: 800;
    padding: 3px 8px;
    border-radius: 4px;
    display: inline-block;
    margin-bottom: 8px;
    letter-spacing: 0.5px;
}

.shortcut-rule-text {
    font-size: 14px;
    color: #ffffff;
    font-weight: 500;
    margin: 0;
    line-height: 1.5;
}

.shortcut-rule-container {
    border-bottom: 1px solid rgba(255, 255, 255, 0.08);
    padding-bottom: 16px;
    margin-bottom: 16px;
}

.shortcut-calculation {
    background: rgba(0, 184, 148, 0.04);
    border: 1px solid rgba(0, 184, 148, 0.25);
    border-radius: 8px;
    padding: 14px 18px;
    margin-top: 14px;
    animation: slideDown 0.25s ease-out;
}