/* 
   Basic English Explorer - Custom Stylesheet
   Designed with a futuristic dark glassmorphism theme and glowing neon accents.
*/

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

:root {
    --bg-main: #0a0814;
    --bg-surface: rgba(18, 14, 38, 0.7);
    --bg-card: rgba(28, 22, 59, 0.6);
    --border-color: rgba(255, 255, 255, 0.08);
    
    --primary: #9d4edd;
    --primary-glow: rgba(157, 78, 221, 0.4);
    --accent-cyan: #00f2fe;
    --accent-cyan-glow: rgba(0, 242, 254, 0.4);
    --accent-pink: #ff007f;
    --accent-pink-glow: rgba(255, 0, 127, 0.4);
    
    --success: #10b981;
    --success-glow: rgba(16, 185, 129, 0.3);
    --warning: #fbbf24;
    --danger: #ef4444;
    
    --text-main: #f1f5f9;
    --text-muted: #94a3b8;
    --text-inverse: #0a0814;
    
    --font-sans: 'Outfit', 'Noto Sans SC', system-ui, -apple-system, sans-serif;
    --transition-smooth: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    background-color: var(--bg-main);
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(59, 23, 119, 0.15) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(13, 76, 121, 0.15) 0%, transparent 40%);
    background-attachment: fixed;
    color: var(--text-main);
    font-family: var(--font-sans);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
    background: var(--bg-card);
    border-radius: 4px;
    border: 1px solid var(--border-color);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}

/* Glass Container Base Styling */
.glass-panel {
    background: var(--bg-surface);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

/* Header & Navigation */
header {
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 8, 20, 0.85);
    backdrop-filter: blur(12px);
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.8rem;
    font-weight: 700;
    font-size: 1.4rem;
    background: linear-gradient(135deg, var(--accent-cyan), var(--primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    cursor: pointer;
}

.logo i {
    background: linear-gradient(135deg, var(--accent-cyan), var(--primary));
    -webkit-background-clip: border-box;
    -webkit-text-fill-color: initial;
    color: var(--accent-cyan);
    font-size: 1.6rem;
}

.stats-summary {
    display: flex;
    gap: 1.5rem;
    font-size: 0.9rem;
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.5rem 1rem;
    border-radius: 30px;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
}

.stat-item i.fa-fire { color: var(--warning); }
.stat-item i.fa-trophy { color: var(--accent-cyan); }
.stat-item i.fa-graduation-cap { color: var(--primary); }

.stat-value {
    font-weight: 600;
    color: var(--text-main);
}

/* Main Layout Tabs */
.tab-navigation {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 2rem;
}

.tab-btn {
    background: transparent;
    border: 1px solid transparent;
    color: var(--text-muted);
    padding: 0.8rem 1.8rem;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    border-radius: 30px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    transition: var(--transition-smooth);
}

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

.tab-btn.active {
    color: var(--accent-cyan);
    background: rgba(0, 242, 254, 0.08);
    border-color: rgba(0, 242, 254, 0.2);
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.1);
}

/* Content Sections */
.tab-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem 3rem 1.5rem;
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.4s ease-out;
}

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

/* Dashboard / Learning Journey Layout */
.dashboard-grid {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.progress-banner {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: 1.5rem;
    padding: 2rem;
}

.banner-desc h2 {
    font-size: 1.6rem;
    margin-bottom: 0.5rem;
}

.banner-desc p {
    color: var(--text-muted);
    font-size: 0.95rem;
    margin-bottom: 1.2rem;
}

.progress-bar-container {
    width: 100%;
    height: 10px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-bar-fill {
    height: 100%;
    width: 0%;
    background: linear-gradient(90deg, var(--primary), var(--accent-cyan));
    border-radius: 10px;
    transition: width 1s ease-out;
}

.progress-banner-stats {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-muted);
}

.banner-circle-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    border-left: 1px solid var(--border-color);
}

.stat-ring {
    position: relative;
    width: 80px;
    height: 80px;
}

.stat-ring svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.ring-bg {
    fill: none;
    stroke: rgba(255, 255, 255, 0.05);
    stroke-width: 6;
}

.ring-fill {
    fill: none;
    stroke: var(--accent-cyan);
    stroke-width: 6;
    stroke-linecap: round;
    stroke-dasharray: 220;
    stroke-dashoffset: 220;
    transition: stroke-dashoffset 1s ease-out;
}

.ring-fill.purple {
    stroke: var(--primary);
}

.ring-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 0.95rem;
    font-weight: 700;
}

/* Category Filters */
.category-filter-bar {
    display: flex;
    justify-content: center;
    gap: 0.8rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.cat-filter-btn {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 0.5rem 1.2rem;
    border-radius: 20px;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-smooth);
}

.cat-filter-btn:hover {
    color: var(--text-main);
    border-color: var(--text-muted);
}

.cat-filter-btn.active {
    color: var(--text-main);
    border-color: var(--primary);
    background: rgba(157, 78, 221, 0.1);
}

/* Lessons Grid */
.lessons-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
    gap: 1.2rem;
}

.lesson-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 1.5rem 1rem;
    text-align: center;
    position: relative;
    cursor: pointer;
    transition: var(--transition-smooth);
    background: var(--bg-card);
}

.lesson-card:hover {
    transform: translateY(-5px);
    border-color: rgba(157, 78, 221, 0.4);
    box-shadow: 0 5px 20px rgba(157, 78, 221, 0.15);
}

.lesson-card.locked {
    opacity: 0.5;
    cursor: not-allowed;
    background: rgba(255, 255, 255, 0.01);
}

.lesson-card.locked:hover {
    transform: none;
    border-color: var(--border-color);
    box-shadow: none;
}

.lesson-card.completed {
    border-color: rgba(16, 185, 129, 0.4);
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.05);
}

.lesson-number {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.2rem;
    color: var(--text-main);
}

.lesson-card.completed .lesson-number {
    color: var(--success);
}

.lesson-card.locked .lesson-number {
    color: var(--text-muted);
}

.lesson-range {
    font-size: 0.75rem;
    color: var(--text-muted);
    margin-bottom: 0.8rem;
}

.lesson-badge {
    font-size: 0.65rem;
    font-weight: 600;
    padding: 0.2rem 0.5rem;
    border-radius: 10px;
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-muted);
}

.lesson-card.completed .lesson-badge {
    background: rgba(16, 185, 129, 0.15);
    color: var(--success);
}

.lesson-card.locked i.fa-lock {
    font-size: 1.2rem;
    color: var(--text-muted);
    margin-top: 0.4rem;
}

/* Flashcard overlay modal */
.learner-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(5, 4, 10, 0.85);
    backdrop-filter: blur(20px);
    z-index: 1000;
    display: none;
    align-items: center;
    justify-content: center;
}

.learner-overlay.active {
    display: flex;
}

.learner-container {
    width: 90%;
    max-width: 520px;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

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

.learner-title {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-main);
}

.close-overlay-btn {
    background: transparent;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.close-overlay-btn:hover {
    color: var(--text-main);
    transform: rotate(90deg);
}

/* The Flashcard itself */
.flashcard {
    height: 360px;
    perspective: 1000px;
    cursor: pointer;
}

.card-inner {
    position: relative;
    width: 100%;
    height: 100%;
    text-align: center;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
    transform-style: preserve-3d;
}

.flashcard.flipped .card-inner {
    transform: rotateY(180deg);
}

.card-front, .card-back {
    position: absolute;
    width: 100%;
    height: 100%;
    -webkit-backface-visibility: hidden;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 2.5rem;
    border-radius: 24px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.5);
    background: radial-gradient(circle at 50% 30%, rgba(43, 34, 84, 0.8) 0%, rgba(20, 16, 43, 0.95) 100%);
    border: 1px solid rgba(255, 255, 255, 0.08);
}

.card-back {
    transform: rotateY(180deg);
    background: radial-gradient(circle at 50% 30%, rgba(18, 55, 87, 0.8) 0%, rgba(11, 25, 41, 0.95) 100%);
    border-color: rgba(0, 242, 254, 0.15);
}

.card-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.card-cat-badge {
    text-transform: uppercase;
    font-weight: 700;
    letter-spacing: 1px;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
}

.word-display {
    font-size: 3.2rem;
    font-weight: 700;
    letter-spacing: -1px;
    color: #fff;
    margin: 1.5rem 0 0.5rem 0;
}

.ipa-display {
    font-size: 1.1rem;
    font-family: var(--font-sans);
    color: var(--accent-cyan);
    letter-spacing: 0.5px;
    font-weight: 400;
}

.trans-display {
    font-size: 1.6rem;
    font-weight: 600;
    color: #fff;
    margin-top: 1.5rem;
}

.example-box {
    text-align: left;
    background: rgba(255, 255, 255, 0.03);
    padding: 1rem;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    font-size: 0.9rem;
    margin: 1rem 0;
    line-height: 1.4rem;
}

.example-eng {
    color: var(--text-main);
    font-weight: 400;
    margin-bottom: 0.3rem;
}

.example-chi {
    color: var(--text-muted);
}

.speak-row {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

.speak-btn {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    color: var(--text-main);
    font-size: 1.2rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition-smooth);
}

.speak-btn:hover {
    background: var(--accent-cyan);
    color: var(--text-inverse);
    box-shadow: 0 0 15px var(--accent-cyan-glow);
    transform: scale(1.08);
}

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

/* Card Controls */
.learner-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 0.5rem;
}

.control-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    width: 48px;
    height: 48px;
    border-radius: 50%;
    color: var(--text-main);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    transition: var(--transition-smooth);
}

.control-btn:hover {
    background: var(--primary);
    border-color: var(--primary);
    box-shadow: 0 0 15px var(--primary-glow);
    transform: scale(1.05);
}

.control-btn:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
    background: transparent;
}

.card-counter {
    font-size: 0.95rem;
    color: var(--text-muted);
    font-weight: 500;
}

.action-row {
    display: flex;
    gap: 1rem;
    margin-top: 0.5rem;
}

.action-btn {
    flex: 1;
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
    border: 1px solid transparent;
}

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

.action-btn.secondary:hover {
    background: rgba(255, 255, 255, 0.08);
}

.action-btn.primary {
    background: linear-gradient(135deg, var(--primary), #7b2cbf);
    color: #fff;
    box-shadow: 0 4px 15px var(--primary-glow);
}

.action-btn.primary:hover {
    box-shadow: 0 4px 20px rgba(157, 78, 221, 0.6);
    transform: translateY(-2px);
}

/* Mastered state toggle */
.mastery-tag {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.2rem 0.6rem;
    border-radius: 12px;
    background: rgba(16, 185, 129, 0.15);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.mastery-tag.not-mastered {
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-muted);
    border-color: var(--border-color);
}

/* Quiz Modal Layout */
.quiz-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    background: rgba(5, 4, 10, 0.9);
    backdrop-filter: blur(25px);
    z-index: 1100;
    display: none;
    align-items: center;
    justify-content: center;
}

.quiz-overlay.active {
    display: flex;
}

.quiz-container {
    width: 90%;
    max-width: 580px;
    padding: 2.5rem;
}

.quiz-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.quiz-progress-bar {
    flex: 1;
    height: 6px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: 10px;
    margin-right: 1.5rem;
    overflow: hidden;
}

.quiz-progress-fill {
    height: 100%;
    width: 0%;
    background: var(--accent-cyan);
    border-radius: 10px;
    transition: width 0.3s ease;
}

.quiz-question-counter {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-weight: 600;
    white-space: nowrap;
}

/* Question Types */
.quiz-body {
    min-height: 220px;
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.quiz-question-type {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1.5px;
    color: var(--accent-cyan);
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.quiz-question-text {
    font-size: 1.6rem;
    font-weight: 600;
    color: #fff;
    margin-bottom: 1.5rem;
    line-height: 2.2rem;
}

.quiz-question-sub {
    font-size: 1rem;
    color: var(--text-muted);
    margin-top: -1rem;
    margin-bottom: 1.5rem;
}

/* Multiple choice options */
.quiz-options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    margin-top: 1rem;
}

.quiz-option-btn {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 1rem 1.2rem;
    border-radius: 14px;
    font-family: var(--font-sans);
    font-size: 1rem;
    color: var(--text-main);
    text-align: left;
    cursor: pointer;
    transition: var(--transition-smooth);
    display: flex;
    align-items: center;
    gap: 0.8rem;
}

.quiz-option-btn:hover {
    background: rgba(255, 255, 255, 0.06);
    border-color: rgba(255, 255, 255, 0.2);
}

.quiz-option-btn .option-letter {
    width: 26px;
    height: 26px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
}

.quiz-option-btn.correct {
    background: rgba(16, 185, 129, 0.15);
    border-color: var(--success);
    color: var(--success);
    box-shadow: 0 0 15px var(--success-glow);
}

.quiz-option-btn.correct .option-letter {
    background: var(--success);
    color: var(--text-inverse);
    border-color: var(--success);
}

.quiz-option-btn.incorrect {
    background: rgba(239, 68, 68, 0.15);
    border-color: var(--danger);
    color: var(--danger);
}

.quiz-option-btn.incorrect .option-letter {
    background: var(--danger);
    color: #fff;
    border-color: var(--danger);
}

/* Spelling Input */
.spelling-container {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    margin-top: 1rem;
}

.spelling-input {
    width: 100%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    font-size: 1.6rem;
    font-family: var(--font-sans);
    color: #fff;
    border-radius: 14px;
    text-align: center;
    letter-spacing: 2px;
    outline: none;
    transition: var(--transition-smooth);
}

.spelling-input:focus {
    border-color: var(--accent-cyan);
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.15);
    background: rgba(255, 255, 255, 0.05);
}

/* Quiz Audio Button */
.quiz-speak-btn {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    background: rgba(0, 242, 254, 0.06);
    border: 1px solid rgba(0, 242, 254, 0.2);
    color: var(--accent-cyan);
    font-size: 1.6rem;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem auto;
    transition: var(--transition-smooth);
}

.quiz-speak-btn:hover {
    background: var(--accent-cyan);
    color: var(--text-inverse);
    box-shadow: 0 0 20px var(--accent-cyan-glow);
    transform: scale(1.05);
}

/* Quiz Results Screen */
.quiz-results {
    text-align: center;
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.results-title {
    font-size: 2rem;
    font-weight: 700;
}

.results-score-ring {
    position: relative;
    width: 140px;
    height: 140px;
    margin: 1rem 0;
}

.results-score-ring svg {
    width: 100%;
    height: 100%;
    transform: rotate(-90deg);
}

.results-score-ring .ring-bg {
    stroke-width: 10;
}

.results-score-ring .ring-fill {
    stroke-width: 10;
    stroke-dasharray: 440;
    stroke-dashoffset: 440;
}

.results-score-text {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 1.8rem;
    font-weight: 700;
}

.results-desc {
    color: var(--text-muted);
    font-size: 1.05rem;
    line-height: 1.5rem;
    max-width: 320px;
}

.results-desc span {
    font-weight: 600;
    color: var(--text-main);
}

/* Dictionary Tab Layout */
.dictionary-controls {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.search-wrapper {
    flex: 1;
    position: relative;
}

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

.search-input {
    width: 100%;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.8rem 1.2rem 0.8rem 2.8rem;
    border-radius: 12px;
    font-family: var(--font-sans);
    color: #fff;
    font-size: 1rem;
    outline: none;
    transition: var(--transition-smooth);
}

.search-input:focus {
    border-color: var(--accent-cyan);
    box-shadow: 0 0 15px rgba(0, 242, 254, 0.1);
}

.dict-filter-select {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    padding: 0.8rem 1.5rem;
    border-radius: 12px;
    color: var(--text-muted);
    font-family: var(--font-sans);
    font-size: 0.95rem;
    cursor: pointer;
    outline: none;
    transition: var(--transition-smooth);
}

.dict-filter-select:focus {
    border-color: var(--accent-cyan);
}

/* Vocabulary Grid */
.vocab-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.2rem;
}

.vocab-card {
    padding: 1.2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    transition: var(--transition-smooth);
}

.vocab-card:hover {
    border-color: rgba(255, 255, 255, 0.15);
    background: rgba(255, 255, 255, 0.02);
}

.vocab-info {
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
}

.vocab-word-row {
    display: flex;
    align-items: center;
    gap: 0.6rem;
}

.vocab-word {
    font-size: 1.2rem;
    font-weight: 600;
}

.vocab-ipa {
    font-size: 0.8rem;
    color: var(--accent-cyan);
}

.vocab-trans {
    font-size: 0.85rem;
    color: var(--text-muted);
    line-height: 1.2rem;
    max-width: 180px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.vocab-card-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.vocab-speak-btn {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    transition: var(--transition-smooth);
}

.vocab-speak-btn:hover {
    background: var(--accent-cyan);
    color: var(--text-inverse);
    border-color: var(--accent-cyan);
}

.vocab-mastered-btn {
    width: 34px;
    height: 34px;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    color: var(--text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.85rem;
    transition: var(--transition-smooth);
}

.vocab-mastered-btn:hover {
    color: var(--success);
    border-color: rgba(16, 185, 129, 0.3);
    background: rgba(16, 185, 129, 0.06);
}

.vocab-card.is-mastered .vocab-mastered-btn {
    color: var(--success);
    background: rgba(16, 185, 129, 0.1);
    border-color: rgba(16, 185, 129, 0.2);
}

.vocab-card.is-mastered .vocab-word {
    color: var(--success);
}

/* Analytics Tab Layout */
.analytics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.chart-card {
    padding: 2rem;
}

.chart-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    color: var(--text-main);
}

.chart-title i {
    color: var(--accent-cyan);
}

.bars-container {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.bar-row {
    display: flex;
    flex-direction: column;
    gap: 0.4rem;
}

.bar-label-row {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
}

.bar-label {
    font-weight: 500;
    color: var(--text-main);
    text-transform: capitalize;
}

.bar-value {
    color: var(--text-muted);
}

.analytics-bar-bg {
    width: 100%;
    height: 8px;
    background: rgba(255, 255, 255, 0.04);
    border-radius: 10px;
    overflow: hidden;
}

.analytics-bar-fill {
    height: 100%;
    border-radius: 10px;
    width: 0%;
    transition: width 1s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Color codes for categories */
.operations-bar { background: linear-gradient(90deg, #9d4edd, #c77dff); }
.general-bar { background: linear-gradient(90deg, #00f2fe, #4facfe); }
.picturable-bar { background: linear-gradient(90deg, #ff007f, #ff758c); }
.qualities-bar { background: linear-gradient(90deg, #fbbf24, #f59e0b); }
.opposites-bar { background: linear-gradient(90deg, #ef4444, #f87171); }

/* Quick Info Panel */
.stats-info-box {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.info-item {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 0.4rem;
}

.info-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    font-weight: 500;
}

.info-number {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--text-main);
}

.info-number.highlight-cyan { color: var(--accent-cyan); }
.info-number.highlight-purple { color: var(--primary); }
.info-number.highlight-green { color: var(--success); }

/* Reset Progress Area */
.reset-zone {
    grid-column: span 2;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem 2rem;
    border-color: rgba(239, 68, 68, 0.15);
    background: rgba(239, 68, 68, 0.02);
}

.reset-desc h4 {
    font-size: 1rem;
    color: var(--danger);
    margin-bottom: 0.2rem;
}

.reset-desc p {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.reset-btn {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: var(--danger);
    padding: 0.6rem 1.2rem;
    border-radius: 20px;
    font-family: var(--font-sans);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition-smooth);
}

.reset-btn:hover {
    background: var(--danger);
    color: #fff;
}

/* Toast Notification */
.toast {
    position: fixed;
    bottom: 2rem;
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 0.8rem 1.5rem;
    border-radius: 30px;
    box-shadow: 0 5px 20px rgba(0, 0, 0, 0.5);
    z-index: 2000;
    font-size: 0.9rem;
    display: flex;
    align-items: center;
    gap: 0.6rem;
    transition: var(--transition-smooth);
    opacity: 0;
    pointer-events: none;
}

.toast.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.toast i {
    color: var(--accent-cyan);
}

.toast i.fa-check-circle {
    color: var(--success);
}

/* Responsive Utilities */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 1rem;
        align-items: flex-start;
        padding: 1.2rem 1.5rem;
    }
    
    .stats-summary {
        width: 100%;
        justify-content: space-between;
    }
    
    .progress-banner {
        grid-template-columns: 1fr;
        padding: 1.5rem;
    }
    
    .banner-circle-stat {
        border-left: none;
        border-top: 1px solid var(--border-color);
        padding-top: 1.2rem;
        flex-direction: row;
        justify-content: space-around;
    }
    
    .quiz-options-grid {
        grid-template-columns: 1fr;
    }
    
    .analytics-grid {
        grid-template-columns: 1fr;
    }
    
    .reset-zone {
        grid-column: span 1;
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}