/* ============================================
   LinguaFlow - Premium English Learning App
   Design: Glassmorphism + Duolingo-style 3D + Gamification
   ============================================ */

/* ===== CSS Variables / Design Tokens ===== */
:root {
    /* Brand Colors */
    --primary: #6C5CE7;
    --primary-dark: #5A4BD1;
    --primary-shadow: #4834b5;
    --primary-glow: rgba(108, 92, 231, 0.4);

    --accent-green: #00D68F;
    --accent-green-dark: #00b377;
    --accent-green-shadow: #009963;

    --accent-blue: #1CB0F6;
    --accent-blue-dark: #1899d6;

    --accent-orange: #FF9F43;
    --accent-orange-dark: #e6862e;

    --accent-red: #FF6B6B;
    --accent-red-dark: #e05252;

    --accent-yellow: #FFC800;
    --accent-yellow-dark: #cca100;

    /* Surface Colors */
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a3e;
    --bg-card: rgba(26, 26, 62, 0.7);
    --bg-card-solid: #1e1e4a;
    --bg-glass: rgba(255, 255, 255, 0.05);
    --bg-glass-hover: rgba(255, 255, 255, 0.08);
    --bg-sidebar: rgba(15, 15, 35, 0.95);

    /* Text Colors */
    --text-primary: #f0f0ff;
    --text-secondary: #a0a0cc;
    --text-muted: #6b6b99;

    /* Borders */
    --border-subtle: rgba(255, 255, 255, 0.08);
    --border-medium: rgba(255, 255, 255, 0.12);
    --border-accent: rgba(108, 92, 231, 0.3);

    /* Layout */
    --sidebar-width: 260px;
    --radius-sm: 10px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-xl: 24px;
    --radius-pill: 999px;

    /* Typography */
    --font-primary: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.2);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 40px rgba(108, 92, 231, 0.15);

    /* Transitions */
    --spring: cubic-bezier(0.34, 1.56, 0.64, 1);
    --smooth: cubic-bezier(0.4, 0, 0.2, 1);
    --bounce: cubic-bezier(0.175, 0.885, 0.32, 1.275);
}

/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
}

/* ===== Animated Background Orbs ===== */
.bg-orbs {
    position: fixed;
    inset: 0;
    pointer-events: none;
    z-index: 0;
    overflow: hidden;
}

.orb {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.4;
}

.orb-1 {
    width: 500px;
    height: 500px;
    background: radial-gradient(circle, var(--primary) 0%, transparent 70%);
    top: -150px;
    right: -100px;
    animation: orbFloat1 20s ease-in-out infinite;
}

.orb-2 {
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, #a855f7 0%, transparent 70%);
    bottom: -100px;
    left: -100px;
    animation: orbFloat2 25s ease-in-out infinite;
}

.orb-3 {
    width: 300px;
    height: 300px;
    background: radial-gradient(circle, var(--accent-blue) 0%, transparent 70%);
    top: 50%;
    left: 40%;
    animation: orbFloat3 18s ease-in-out infinite;
}

@keyframes orbFloat1 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(-80px, 60px) scale(1.1); }
    66% { transform: translate(40px, -40px) scale(0.9); }
}

@keyframes orbFloat2 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    33% { transform: translate(60px, -80px) scale(1.15); }
    66% { transform: translate(-50px, 30px) scale(0.85); }
}

@keyframes orbFloat3 {
    0%, 100% { transform: translate(0, 0) scale(1); }
    50% { transform: translate(-60px, -60px) scale(1.2); }
}

/* ===== Sidebar Navigation ===== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    width: var(--sidebar-width);
    background: var(--bg-sidebar);
    backdrop-filter: blur(20px);
    border-right: 1px solid var(--border-subtle);
    display: flex;
    flex-direction: column;
    z-index: 100;
    transition: transform 0.4s var(--smooth);
}

.sidebar-header {
    padding: 24px 20px;
    border-bottom: 1px solid var(--border-subtle);
}

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

.logo-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--primary), #a855f7);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 12px rgba(108, 92, 231, 0.3);
    animation: logoFloat 4s ease-in-out infinite;
}

@keyframes logoFloat {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-3px); }
}

.logo-text {
    font-family: var(--font-primary);
    font-size: 1.3rem;
    font-weight: 700;
    background: linear-gradient(135deg, #fff 0%, #c4b5fd 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.nav-section {
    padding: 16px 12px;
    flex: 1;
}

.nav-label {
    display: block;
    font-size: 0.65rem;
    font-weight: 700;
    letter-spacing: 1.5px;
    color: var(--text-muted);
    padding: 0 12px;
    margin-bottom: 8px;
    text-transform: uppercase;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    padding: 12px 16px;
    background: transparent;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.25s var(--smooth);
    position: relative;
    overflow: hidden;
    margin-bottom: 4px;
}

.nav-item::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, var(--primary), #a855f7);
    opacity: 0;
    transition: opacity 0.25s var(--smooth);
    border-radius: inherit;
}

.nav-item:hover {
    color: var(--text-primary);
    border-color: var(--border-medium);
    background: var(--bg-glass-hover);
}

.nav-item.active {
    color: #fff;
    border-color: transparent;
    box-shadow: 0 4px 0 0 var(--primary-shadow), 0 4px 15px rgba(108, 92, 231, 0.3);
    transform: translateY(-1px);
}

.nav-item.active::before {
    opacity: 1;
}

.nav-icon, .nav-text {
    position: relative;
    z-index: 1;
}

.nav-icon {
    font-size: 1.1rem;
}

.sidebar-footer {
    padding: 16px 12px;
    border-top: 1px solid var(--border-subtle);
}

.streak-badge {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    background: rgba(255, 159, 67, 0.1);
    border: 1px solid rgba(255, 159, 67, 0.2);
    border-radius: var(--radius-md);
    animation: floatStreak 4s ease-in-out infinite;
}

@keyframes floatStreak {
    0%, 100% { transform: translateY(0); box-shadow: 0 4px 15px rgba(255, 159, 67, 0.1); }
    50% { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(255, 159, 67, 0.2); }
}

.streak-fire {
    font-size: 1.4rem;
    animation: pulseIcon 2s ease-in-out infinite;
}

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

.streak-count {
    font-family: var(--font-primary);
    font-size: 1.3rem;
    font-weight: 800;
    color: var(--accent-orange);
}

.streak-label {
    font-size: 0.75rem;
    color: var(--text-muted);
}

/* ===== Mobile Nav Toggle ===== */
.mobile-nav-toggle {
    display: none;
    position: fixed;
    top: 16px;
    left: 16px;
    z-index: 200;
    width: 44px;
    height: 44px;
    background: var(--bg-card-solid);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-sm);
    cursor: pointer;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 5px;
}

.mobile-nav-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--text-primary);
    border-radius: 2px;
    transition: all 0.3s var(--smooth);
}

/* ===== Main Content ===== */
.main-content {
    margin-left: var(--sidebar-width);
    padding: 32px 40px;
    position: relative;
    z-index: 1;
    min-height: 100vh;
}

/* ===== Page System ===== */
.page {
    display: none;
    animation: pageIn 0.5s var(--bounce);
}

.page.active {
    display: block;
}

@keyframes pageIn {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.98);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

/* ===== Page Header ===== */
.page-header {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    margin-bottom: 28px;
    flex-wrap: wrap;
    gap: 16px;
}

.page-title {
    font-family: var(--font-primary);
    font-size: 2rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff 0%, #c4b5fd 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 4px;
}

.page-subtitle {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.header-stats {
    display: flex;
    gap: 12px;
}

.stat-pill {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-pill);
    font-size: 0.85rem;
    transition: all 0.3s var(--smooth);
}

.stat-pill:hover {
    background: var(--bg-glass-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

.stat-value {
    font-family: var(--font-primary);
    font-weight: 700;
    color: var(--accent-yellow);
}

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

/* ===== XP Progress Section ===== */
.xp-progress-section {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 20px 24px;
    margin-bottom: 28px;
}

.xp-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 10px;
    font-weight: 500;
}

.xp-bar {
    height: 14px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-pill);
    overflow: hidden;
    position: relative;
}

.xp-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), #a855f7, var(--accent-blue));
    background-size: 200% 100%;
    border-radius: var(--radius-pill);
    transition: width 0.8s var(--smooth);
    position: relative;
    animation: xpShimmer 3s linear infinite;
}

.xp-fill::after {
    content: '';
    position: absolute;
    top: 0;
    right: 0;
    width: 30px;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.3));
    border-radius: var(--radius-pill);
}

@keyframes xpShimmer {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* ===== Stats Grid (Dashboard) ===== */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 24px;
    text-align: center;
    transition: all 0.35s var(--smooth);
    position: relative;
    overflow: hidden;
    /* Duolingo-style chunky bottom border */
    border-bottom-width: 4px;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.stat-card-purple::before { background: linear-gradient(90deg, var(--primary), #a855f7); }
.stat-card-purple { border-bottom-color: var(--primary-shadow); }
.stat-card-blue::before { background: linear-gradient(90deg, var(--accent-blue), #0ea5e9); }
.stat-card-blue { border-bottom-color: var(--accent-blue-dark); }
.stat-card-green::before { background: linear-gradient(90deg, var(--accent-green), #22c55e); }
.stat-card-green { border-bottom-color: var(--accent-green-shadow); }
.stat-card-orange::before { background: linear-gradient(90deg, var(--accent-orange), #f97316); }
.stat-card-orange { border-bottom-color: var(--accent-orange-dark); }

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
    background: var(--bg-glass-hover);
}

/* Tactile click — Duolingo-style */
.stat-card:active {
    transform: translateY(2px);
    box-shadow: none;
}

.stat-card-icon {
    font-size: 2rem;
    margin-bottom: 8px;
}

.stat-card-value {
    font-family: var(--font-primary);
    font-size: 1.8rem;
    font-weight: 800;
    color: var(--text-primary);
    margin-bottom: 4px;
}

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

/* ===== Section Title ===== */
.section-title {
    font-family: var(--font-primary);
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 16px;
}

/* ===== Quick Actions ===== */
.quick-actions {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 14px;
    margin-bottom: 32px;
}

.action-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 18px 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.25s var(--smooth);
    text-align: left;
    font-family: var(--font-body);
    color: var(--text-primary);
    position: relative;
    overflow: hidden;
}

/* Shine sweep effect on hover */
.action-card::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.05), transparent);
    transition: none;
}

.action-card:hover::after {
    left: 125%;
    transition: left 0.7s ease-in-out;
}

.action-card:hover {
    transform: translateY(-3px) scale(1.01);
    border-color: var(--border-accent);
    background: var(--bg-glass-hover);
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.15);
}

.action-card:active {
    transform: translateY(3px);
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.2);
}

.action-icon {
    font-size: 2rem;
    width: 50px;
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-glass);
    border-radius: var(--radius-md);
    flex-shrink: 0;
}

.action-info h3 {
    font-family: var(--font-primary);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 2px;
}

.action-info p {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.action-arrow {
    margin-left: auto;
    font-size: 1.2rem;
    color: var(--text-muted);
    transition: transform 0.3s var(--smooth);
}

.action-card:hover .action-arrow {
    transform: translateX(4px);
    color: var(--primary);
}

/* ===== Daily Word Card ===== */
.daily-word-card {
    background: linear-gradient(135deg, rgba(108, 92, 231, 0.15), rgba(168, 85, 247, 0.1));
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-accent);
    border-radius: var(--radius-xl);
    padding: 32px;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: floatWithGlow 6s ease-in-out infinite;
}

@keyframes floatWithGlow {
    0%, 100% { transform: translateY(0); box-shadow: 0 8px 30px rgba(108, 92, 231, 0.15); }
    50% { transform: translateY(-5px); box-shadow: 0 14px 40px rgba(108, 92, 231, 0.25); }
}

.daily-word-badge {
    display: inline-block;
    padding: 6px 16px;
    background: rgba(108, 92, 231, 0.2);
    border-radius: var(--radius-pill);
    font-size: 0.75rem;
    font-weight: 600;
    color: #c4b5fd;
    margin-bottom: 16px;
}

.daily-word {
    font-family: var(--font-primary);
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff, #c4b5fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 6px;
}

.daily-pronunciation {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 12px;
    font-style: italic;
}

.daily-meaning {
    font-size: 1.1rem;
    color: var(--accent-green);
    font-weight: 600;
    margin-bottom: 12px;
}

.daily-example {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
    max-width: 500px;
    margin: 0 auto;
    line-height: 1.5;
}

/* ===== Category Tabs ===== */
.category-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 24px;
    flex-wrap: wrap;
}

.cat-tab {
    padding: 10px 20px;
    background: var(--bg-glass);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 4px;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    user-select: none;
}

.cat-tab:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
    border-color: var(--border-medium);
}

.cat-tab.active {
    background: linear-gradient(135deg, var(--primary), #a855f7);
    border-color: var(--primary-shadow);
    color: #fff;
    box-shadow: 0 4px 0 0 var(--primary-shadow);
    transform: translateY(-1px);
}

.cat-tab.active:active {
    transform: translateY(3px);
    box-shadow: 0 0 0 0 var(--primary-shadow);
}

/* ===== Flashcard Area ===== */
.flashcard-area {
    max-width: 600px;
    margin: 0 auto;
}

.flashcard-progress {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.85rem;
    margin-bottom: 16px;
    font-weight: 500;
}

.fc-progress-bar {
    height: 8px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-pill);
    overflow: hidden;
    margin-top: 8px;
}

.fc-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-green), #22c55e);
    border-radius: var(--radius-pill);
    transition: width 0.5s var(--smooth);
}

.flashcard-container {
    perspective: 1200px;
    margin-bottom: 24px;
}

.flashcard {
    width: 100%;
    min-height: 320px;
    position: relative;
    cursor: pointer;
    transform-style: preserve-3d;
    transition: transform 0.7s var(--smooth);
    border-radius: var(--radius-xl);
}

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

.flashcard-front, .flashcard-back {
    position: absolute;
    inset: 0;
    backface-visibility: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 40px;
    border-radius: var(--radius-xl);
    border: 2px solid var(--border-medium);
    border-bottom-width: 6px;
}

.flashcard-front {
    background: linear-gradient(145deg, rgba(108, 92, 231, 0.15), rgba(26, 26, 62, 0.9));
    backdrop-filter: blur(10px);
    border-bottom-color: var(--primary-shadow);
}

.flashcard-back {
    background: linear-gradient(145deg, rgba(0, 214, 143, 0.1), rgba(26, 26, 62, 0.9));
    backdrop-filter: blur(10px);
    transform: rotateY(180deg);
    border-bottom-color: var(--accent-green-shadow);
}

.fc-word {
    font-family: var(--font-primary);
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff, #c4b5fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.fc-pronunciation {
    color: var(--text-muted);
    font-size: 1rem;
    font-style: italic;
    margin-bottom: 16px;
}

.fc-hint {
    color: var(--text-muted);
    font-size: 0.8rem;
    margin-top: 20px;
    opacity: 0.6;
}

.fc-meaning {
    font-family: var(--font-primary);
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-green);
    margin-bottom: 16px;
}

.fc-example {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-style: italic;
    text-align: center;
    line-height: 1.5;
}

/* Flashcard Actions */
.flashcard-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

.fc-btn {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 14px 32px;
    border: 2px solid transparent;
    border-bottom-width: 5px;
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 0.95rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    user-select: none;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.fc-btn:active {
    transform: translateY(3px);
    box-shadow: 0 0 0 0 transparent !important;
}

.fc-btn-wrong {
    background: var(--accent-red);
    border-color: var(--accent-red-dark);
    color: #fff;
    box-shadow: 0 4px 0 0 var(--accent-red-dark);
}

.fc-btn-wrong:hover {
    background: var(--accent-red-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 0 0 var(--accent-red-dark), 0 6px 20px rgba(255, 107, 107, 0.3);
}

.fc-btn-right {
    background: var(--accent-green);
    border-color: var(--accent-green-shadow);
    color: #fff;
    box-shadow: 0 4px 0 0 var(--accent-green-shadow);
}

.fc-btn-right:hover {
    background: var(--accent-green-dark);
    transform: translateY(-2px);
    box-shadow: 0 6px 0 0 var(--accent-green-shadow), 0 6px 20px rgba(0, 214, 143, 0.3);
}

/* ===== Quiz Section ===== */
.quiz-types {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.quiz-type-card {
    padding: 28px 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s var(--smooth);
    text-align: center;
    font-family: var(--font-body);
    color: var(--text-primary);
}

.quiz-type-card:hover {
    transform: translateY(-4px) scale(1.02);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-md), var(--shadow-glow);
}

.quiz-type-card:active {
    transform: translateY(3px);
    box-shadow: none;
}

.quiz-type-card .qt-icon {
    font-size: 2.5rem;
    margin-bottom: 12px;
}

.quiz-type-card h3 {
    font-family: var(--font-primary);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 6px;
}

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

/* Quiz Area */
.quiz-area {
    max-width: 700px;
    margin: 0 auto;
}

.quiz-header {
    margin-bottom: 24px;
}

.quiz-progress-info {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-secondary);
    font-weight: 600;
    margin-bottom: 8px;
}

.quiz-progress-bar {
    height: 10px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-pill);
    overflow: hidden;
    margin-bottom: 12px;
}

.quiz-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary), #a855f7);
    border-radius: var(--radius-pill);
    transition: width 0.5s var(--smooth);
}

.quiz-timer {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    font-family: var(--font-primary);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--accent-orange);
}

.quiz-question-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 32px;
    margin-bottom: 20px;
    text-align: center;
}

.quiz-question {
    font-family: var(--font-primary);
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.5;
}

.quiz-hint {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 8px;
    font-style: italic;
}

/* Quiz Options - Duolingo-style cards */
.quiz-options {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    margin-bottom: 20px;
}

.quiz-option {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 18px 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-medium);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    text-align: center;
    min-height: 60px;
}

.quiz-option:hover {
    background: rgba(108, 92, 231, 0.1);
    border-color: var(--primary);
    transform: translateY(-2px);
    box-shadow: 0 6px 0 0 var(--primary-shadow);
}

.quiz-option:active {
    transform: translateY(3px);
    box-shadow: 0 0 0 0 transparent;
}

.quiz-option.correct {
    background: rgba(0, 214, 143, 0.15);
    border-color: var(--accent-green);
    box-shadow: 0 4px 0 0 var(--accent-green-shadow);
    color: var(--accent-green);
    animation: correctPop 0.4s var(--bounce);
}

.quiz-option.wrong {
    background: rgba(255, 107, 107, 0.15);
    border-color: var(--accent-red);
    box-shadow: 0 4px 0 0 var(--accent-red-dark);
    color: var(--accent-red);
    animation: shake 0.5s ease-in-out;
}

.quiz-option.disabled {
    pointer-events: none;
    opacity: 0.5;
}

@keyframes correctPop {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); }
    100% { transform: scale(1); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20% { transform: translateX(-8px); }
    40% { transform: translateX(8px); }
    60% { transform: translateX(-4px); }
    80% { transform: translateX(4px); }
}

/* Fill in the blank */
.quiz-fill {
    text-align: center;
    margin-bottom: 20px;
}

.fill-input {
    width: 100%;
    max-width: 400px;
    padding: 16px 24px;
    background: var(--bg-glass);
    border: 2px solid var(--border-medium);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1.1rem;
    font-weight: 500;
    outline: none;
    transition: all 0.3s var(--smooth);
    margin-bottom: 16px;
}

.fill-input:focus {
    border-color: var(--primary);
    box-shadow: 0 0 20px rgba(108, 92, 231, 0.2);
}

.fill-input.correct {
    border-color: var(--accent-green);
    box-shadow: 0 0 20px rgba(0, 214, 143, 0.2);
}

.fill-input.wrong {
    border-color: var(--accent-red);
    box-shadow: 0 0 20px rgba(255, 107, 107, 0.2);
}

/* True/False */
.quiz-tf {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 20px;
}

.tf-btn {
    padding: 18px 48px;
    border: 2px solid var(--border-medium);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    background: var(--bg-glass);
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1.1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
}

.tf-btn:hover {
    transform: translateY(-3px);
}

.tf-btn:active {
    transform: translateY(3px);
    box-shadow: none;
}

.tf-true:hover {
    background: rgba(0, 214, 143, 0.15);
    border-color: var(--accent-green);
    box-shadow: 0 6px 0 0 var(--accent-green-shadow);
}

.tf-false:hover {
    background: rgba(255, 107, 107, 0.15);
    border-color: var(--accent-red);
    box-shadow: 0 6px 0 0 var(--accent-red-dark);
}

/* Quiz Feedback */
.quiz-feedback {
    padding: 20px 24px;
    border-radius: var(--radius-lg);
    margin-bottom: 20px;
    animation: slideUp 0.4s var(--bounce);
}

.quiz-feedback.correct-feedback {
    background: rgba(0, 214, 143, 0.1);
    border: 1px solid rgba(0, 214, 143, 0.3);
}

.quiz-feedback.wrong-feedback {
    background: rgba(255, 107, 107, 0.1);
    border: 1px solid rgba(255, 107, 107, 0.3);
}

.feedback-content {
    font-size: 0.95rem;
    font-weight: 600;
    line-height: 1.5;
    margin-bottom: 12px;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Results Card (shared) ===== */
.results-card {
    text-align: center;
    padding: 48px 32px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    max-width: 500px;
    margin: 40px auto;
    animation: popInStaggered 0.5s var(--bounce);
}

@keyframes popInStaggered {
    from { opacity: 0; transform: translateY(20px) scale(0.9); }
    to { opacity: 1; transform: translateY(0) scale(1); }
}

.results-emoji {
    font-size: 4rem;
    margin-bottom: 16px;
    animation: pulseIcon 2s ease-in-out infinite;
}

.results-card h2 {
    font-family: var(--font-primary);
    font-size: 1.6rem;
    font-weight: 800;
    background: linear-gradient(135deg, #fff, #c4b5fd);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 8px;
}

.results-card p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.results-stats {
    display: flex;
    justify-content: center;
    gap: 32px;
    margin-bottom: 32px;
}

.result-stat {
    display: flex;
    flex-direction: column;
    align-items: center;
}

.result-value {
    font-family: var(--font-primary);
    font-size: 2rem;
    font-weight: 800;
    color: var(--accent-yellow);
}

.result-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 4px;
}

/* ===== Primary Button ===== */
.btn-primary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    background: linear-gradient(135deg, var(--primary), #a855f7);
    border: 2px solid var(--primary-shadow);
    border-bottom-width: 5px;
    border-radius: var(--radius-md);
    color: #fff;
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    user-select: none;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 4px 0 0 var(--primary-shadow);
    position: relative;
    overflow: hidden;
}

.btn-primary::after {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 50%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.15), transparent);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 0 0 var(--primary-shadow), 0 6px 20px rgba(108, 92, 231, 0.3);
}

.btn-primary:hover::after {
    left: 125%;
    transition: left 0.6s ease;
}

.btn-primary:active {
    transform: translateY(3px);
    box-shadow: 0 0 0 0 var(--primary-shadow);
}

/* ===== Reading Section ===== */
.reading-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 16px;
}

.reading-card {
    padding: 24px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    cursor: pointer;
    transition: all 0.3s var(--smooth);
}

.reading-card:hover {
    transform: translateY(-4px);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-md);
}

.reading-card:active {
    transform: translateY(2px);
    box-shadow: none;
}

.reading-card h3 {
    font-family: var(--font-primary);
    font-size: 1.1rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.reading-card p {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 12px;
    line-height: 1.5;
}

.reading-card-meta {
    display: flex;
    gap: 8px;
    align-items: center;
}

.level-badge {
    padding: 4px 12px;
    border-radius: var(--radius-pill);
    font-size: 0.7rem;
    font-weight: 700;
}

.level-easy { background: rgba(0, 214, 143, 0.15); color: var(--accent-green); }
.level-medium { background: rgba(255, 200, 0, 0.15); color: var(--accent-yellow); }
.level-hard { background: rgba(255, 107, 107, 0.15); color: var(--accent-red); }

.reading-card .completed-badge {
    display: inline-block;
    padding: 4px 12px;
    background: rgba(0, 214, 143, 0.15);
    border-radius: var(--radius-pill);
    font-size: 0.7rem;
    font-weight: 700;
    color: var(--accent-green);
}

/* Reading Content */
.back-btn {
    display: inline-flex;
    align-items: center;
    padding: 8px 16px;
    background: var(--bg-glass);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 0.85rem;
    cursor: pointer;
    margin-bottom: 20px;
    transition: all 0.2s var(--smooth);
}

.back-btn:hover {
    background: var(--bg-glass-hover);
    color: var(--text-primary);
}

.reading-article {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-xl);
    padding: 32px;
    margin-bottom: 24px;
}

.reading-article h2 {
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 12px;
}

.reading-meta {
    display: flex;
    gap: 12px;
    align-items: center;
    margin-bottom: 20px;
}

.reading-level-badge {
    padding: 4px 14px;
    border-radius: var(--radius-pill);
    font-size: 0.75rem;
    font-weight: 700;
}

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

.reading-text {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-secondary);
}

.reading-text p {
    margin-bottom: 16px;
}

/* Reading Questions */
.reading-questions {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.rq-card {
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 24px;
}

.rq-card h4 {
    font-family: var(--font-primary);
    font-weight: 600;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.rq-options {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.rq-option {
    padding: 12px 16px;
    background: rgba(255, 255, 255, 0.03);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 4px;
    border-radius: var(--radius-md);
    color: var(--text-secondary);
    font-family: var(--font-body);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    text-align: left;
}

.rq-option:hover {
    background: rgba(108, 92, 231, 0.08);
    border-color: var(--primary);
    color: var(--text-primary);
}

.rq-option:active {
    transform: translateY(2px);
    box-shadow: none;
}

.rq-option.correct {
    background: rgba(0, 214, 143, 0.12);
    border-color: var(--accent-green);
    color: var(--accent-green);
}

.rq-option.wrong {
    background: rgba(255, 107, 107, 0.12);
    border-color: var(--accent-red);
    color: var(--accent-red);
}

.rq-option.disabled {
    pointer-events: none;
    opacity: 0.5;
}

/* ===== Phrases Section ===== */
.phrase-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.phrase-card {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 20px 24px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-subtle);
    border-bottom-width: 4px;
    border-radius: var(--radius-lg);
    transition: all 0.3s var(--smooth);
    cursor: pointer;
}

.phrase-card:hover {
    transform: translateY(-2px);
    border-color: var(--border-accent);
    box-shadow: var(--shadow-sm);
}

.phrase-card:active {
    transform: translateY(2px);
}

.phrase-emoji {
    font-size: 1.8rem;
    flex-shrink: 0;
}

.phrase-content {
    flex: 1;
}

.phrase-en {
    font-family: var(--font-primary);
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.phrase-tr {
    font-size: 0.85rem;
    color: var(--accent-green);
    font-weight: 500;
}

.phrase-pronunciation {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-style: italic;
    margin-top: 2px;
}

.phrase-speak-btn {
    width: 42px;
    height: 42px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(108, 92, 231, 0.15);
    border: 1px solid var(--border-accent);
    border-radius: 50%;
    font-size: 1.1rem;
    cursor: pointer;
    transition: all 0.2s var(--smooth);
    flex-shrink: 0;
    color: var(--text-primary);
}

.phrase-speak-btn:hover {
    background: var(--primary);
    transform: scale(1.1);
}

/* ===== Achievements Section ===== */
.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 16px;
}

.achievement-card {
    padding: 24px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border: 2px solid var(--border-subtle);
    border-bottom-width: 5px;
    border-radius: var(--radius-lg);
    text-align: center;
    transition: all 0.3s var(--smooth);
    position: relative;
    overflow: hidden;
}

.achievement-card.unlocked {
    border-color: rgba(255, 200, 0, 0.3);
    border-bottom-color: var(--accent-yellow-dark);
    animation: floatWithGlow 6s ease-in-out infinite;
}

.achievement-card.locked {
    opacity: 0.5;
    filter: grayscale(0.5);
}

.achievement-card:hover {
    transform: translateY(-3px);
}

.achievement-icon {
    font-size: 3rem;
    margin-bottom: 12px;
}

.achievement-card h3 {
    font-family: var(--font-primary);
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 6px;
    color: var(--text-primary);
}

.achievement-card p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.achievement-progress {
    height: 6px;
    background: rgba(255, 255, 255, 0.08);
    border-radius: var(--radius-pill);
    overflow: hidden;
}

.achievement-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--accent-yellow), var(--accent-orange));
    border-radius: var(--radius-pill);
    transition: width 0.5s var(--smooth);
}

/* ===== XP Popup ===== */
.xp-popup {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: 1000;
    pointer-events: none;
}

.xp-popup.show {
    animation: xpPopup 1.5s var(--bounce) forwards;
}

.xp-popup-text {
    font-family: var(--font-primary);
    font-size: 2.5rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent-yellow), var(--accent-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-shadow: none;
    filter: drop-shadow(0 0 20px rgba(255, 200, 0, 0.5));
}

@keyframes xpPopup {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    30% { opacity: 1; transform: translate(-50%, -70%) scale(1.2); }
    60% { opacity: 1; transform: translate(-50%, -80%) scale(1); }
    100% { opacity: 0; transform: translate(-50%, -120%) scale(0.8); }
}

/* ===== Level Up Modal ===== */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 500;
    animation: fadeIn 0.3s ease;
}

.modal-content {
    background: var(--bg-card-solid);
    border: 1px solid var(--border-medium);
    border-radius: var(--radius-xl);
    padding: 48px 40px;
    text-align: center;
    max-width: 420px;
    width: 90%;
    animation: popInStaggered 0.5s var(--bounce);
}

.levelup-stars {
    font-size: 2.5rem;
    margin-bottom: 16px;
    animation: pulseIcon 1.5s ease-in-out infinite;
}

.levelup-content h2 {
    font-family: var(--font-primary);
    font-size: 1.5rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--accent-yellow), var(--accent-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: 12px;
}

.levelup-number {
    font-family: var(--font-primary);
    font-size: 4rem;
    font-weight: 900;
    background: linear-gradient(135deg, var(--accent-yellow), var(--accent-orange));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin: 16px 0;
}

.levelup-content p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ===== Hidden Utility ===== */
.hidden {
    display: none !important;
}

/* ===== Responsive ===== */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .quiz-types {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.open {
        transform: translateX(0);
    }

    .mobile-nav-toggle {
        display: flex;
    }

    .main-content {
        margin-left: 0;
        padding: 24px 16px;
        padding-top: 70px;
    }

    .page-title {
        font-size: 1.5rem;
    }

    .stats-grid {
        grid-template-columns: 1fr 1fr;
    }

    .quick-actions {
        grid-template-columns: 1fr;
    }

    .quiz-options {
        grid-template-columns: 1fr;
    }

    .flashcard-actions {
        flex-direction: column;
    }

    .fc-btn {
        width: 100%;
        justify-content: center;
    }

    .header-stats {
        display: none;
    }

    .results-stats {
        gap: 16px;
    }

    .daily-word {
        font-size: 1.8rem;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }

    .category-tabs {
        overflow-x: auto;
        flex-wrap: nowrap;
        padding-bottom: 8px;
        -webkit-overflow-scrolling: touch;
    }

    .cat-tab {
        white-space: nowrap;
        flex-shrink: 0;
    }
}

/* ===== Accessibility: Reduced Motion ===== */
@media (prefers-reduced-motion: reduce) {
    .orb,
    .logo-icon,
    .streak-badge,
    .streak-fire,
    .daily-word-card,
    .achievement-card.unlocked,
    .levelup-stars,
    .results-emoji,
    .xp-fill {
        animation: none !important;
    }

    * {
        transition-duration: 0.01ms !important;
    }
}

/* ===== Scrollbar ===== */
::-webkit-scrollbar {
    width: 8px;
}

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

::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-pill);
}

::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.2);
}