/* B1 Congress English Trainer - Design System & Styling */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;600;700;800;900&display=swap');

:root {
    /* Color Palette - Premium Dark Theme with Mining/Event Accents */
    --bg-main: #0b0f19;
    --bg-card: rgba(18, 24, 38, 0.75);
    --bg-card-hover: rgba(28, 36, 56, 0.85);
    --bg-glass: rgba(255, 255, 255, 0.03);
    
    --border-color: rgba(255, 255, 255, 0.08);
    --border-accent: rgba(255, 204, 0, 0.3);
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    
    /* Brand Accents */
    --copper-gold: #f59e0b;
    --gold-glow: rgba(245, 158, 11, 0.25);
    --cyan-accent: #06b6d4;
    --cyan-glow: rgba(6, 182, 212, 0.25);
    --emerald-success: #10b981;
    --rose-error: #f43f5e;
    --purple-vivid: #8b5cf6;
    
    --font-heading: 'Outfit', sans-serif;
    --font-body: 'Inter', sans-serif;
    
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --radius-full: 9999px;
    
    --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.4);
    --shadow-glow: 0 0 30px rgba(245, 158, 11, 0.15);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

[data-theme="light"] {
    --bg-main: #f1f5f9;
    --bg-card: rgba(255, 255, 255, 0.9);
    --bg-card-hover: #ffffff;
    --bg-glass: rgba(0, 0, 0, 0.02);
    --border-color: rgba(0, 0, 0, 0.08);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --shadow-subtle: 0 4px 20px rgba(0, 0, 0, 0.06);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-body);
    background: var(--bg-main);
    background-image: 
        radial-gradient(circle at 15% 15%, rgba(6, 182, 212, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 85% 85%, rgba(245, 158, 11, 0.08) 0%, transparent 40%),
        radial-gradient(circle at 50% 50%, rgba(139, 92, 246, 0.04) 0%, transparent 60%);
    background-attachment: fixed;
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

/* App Header & Navigation */
header.app-header {
    background: rgba(11, 15, 25, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 100;
    padding: 14px 28px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 16px;
}

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

.brand-logo {
    width: 42px;
    height: 42px;
    background: linear-gradient(135deg, var(--copper-gold), #b45309);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    box-shadow: 0 0 15px var(--gold-glow);
    flex-shrink: 0;
}

.brand-text h1 {
    font-family: var(--font-heading);
    font-size: 1.25rem;
    font-weight: 800;
    background: linear-gradient(90deg, #ffffff, var(--copper-gold));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
    line-height: 1.2;
}

.brand-text span {
    font-size: 0.75rem;
    color: var(--cyan-accent);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

/* User Stats Bar */
.user-stats-bar {
    display: flex;
    align-items: center;
    gap: 12px;
}

.stat-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: var(--radius-full);
    font-size: 0.82rem;
    font-weight: 600;
    white-space: nowrap;
}

.stat-badge .icon {
    font-size: 1rem;
}

.stat-badge.xp-badge {
    color: var(--copper-gold);
    border-color: rgba(245, 158, 11, 0.3);
}

.stat-badge.streak-badge {
    color: #f97316;
    border-color: rgba(249, 115, 22, 0.3);
}

.stat-badge.level-badge {
    color: var(--cyan-accent);
    border-color: rgba(6, 182, 212, 0.3);
}

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

.icon-btn {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    min-width: 38px;
    height: 38px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    touch-action: manipulation;
}

.icon-btn:hover {
    background: var(--bg-card-hover);
    border-color: var(--cyan-accent);
    transform: translateY(-2px);
}

/* Main Container Layout */
.app-layout {
    max-width: 1320px;
    margin: 0 auto;
    width: 100%;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 24px;
    flex: 1;
}

/* CAROUSEL NAVIGATION MENU STYLING */
.nav-carousel-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    gap: 8px;
    width: 100%;
}

.carousel-arrow {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--copper-gold);
    width: 38px;
    height: 42px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1rem;
    font-weight: 800;
    cursor: pointer;
    transition: var(--transition);
    flex-shrink: 0;
    touch-action: manipulation;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    z-index: 10;
}

.carousel-arrow:hover {
    background: var(--bg-card-hover);
    border-color: var(--copper-gold);
    color: #fff;
    transform: scale(1.05);
}

.nav-tabs {
    display: flex;
    gap: 10px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    padding: 6px;
    border-radius: var(--radius-lg);
    overflow-x: auto;
    backdrop-filter: blur(12px);
    scroll-snap-type: x mandatory;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none; /* Firefox */
    width: 100%;
}

.nav-tabs::-webkit-scrollbar {
    display: none; /* Chrome/Safari */
}

.nav-tab-btn {
    flex: 0 0 auto;
    min-width: 180px;
    padding: 12px 20px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-heading);
    font-size: 0.92rem;
    font-weight: 600;
    border-radius: var(--radius-md);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    transition: var(--transition);
    white-space: nowrap;
    touch-action: manipulation;
    scroll-snap-align: center;
}

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

.nav-tab-btn.active {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.25), rgba(6, 182, 212, 0.25));
    border: 1px solid var(--copper-gold);
    color: #fff;
    box-shadow: 0 4px 18px rgba(245, 158, 11, 0.2);
}

/* Content Views */
.tab-content {
    display: none;
    animation: fadeIn 0.3s ease-out forwards;
}

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

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

/* Zone Selection Map Grid */
.zone-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 16px;
    margin-bottom: 24px;
}

.zone-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 18px;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    gap: 10px;
    touch-action: manipulation;
}

.zone-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--copper-gold), var(--cyan-accent));
    opacity: 0;
    transition: var(--transition);
}

.zone-card:hover {
    transform: translateY(-4px);
    background: var(--bg-card-hover);
    border-color: rgba(6, 182, 212, 0.4);
    box-shadow: var(--shadow-subtle);
}

.zone-card:hover::before {
    opacity: 1;
}

.zone-card.active-zone {
    border-color: var(--copper-gold);
    box-shadow: var(--shadow-glow);
}

.zone-card.active-zone::before {
    opacity: 1;
}

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

.zone-icon {
    font-size: 2rem;
    background: var(--bg-glass);
    width: 48px;
    height: 48px;
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border-color);
    flex-shrink: 0;
}

.zone-status {
    font-size: 0.72rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: var(--radius-full);
    text-transform: uppercase;
}

.zone-status.completed {
    background: rgba(16, 185, 129, 0.15);
    color: var(--emerald-success);
    border: 1px solid rgba(16, 185, 129, 0.3);
}

.zone-status.in-progress {
    background: rgba(245, 158, 11, 0.15);
    color: var(--copper-gold);
    border: 1px solid rgba(245, 158, 11, 0.3);
}

.zone-title {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 700;
}

.zone-subtitle {
    font-size: 0.8rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.zone-grammar-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-top: 4px;
}

.grammar-tag {
    font-size: 0.68rem;
    background: rgba(6, 182, 212, 0.1);
    color: var(--cyan-accent);
    padding: 3px 8px;
    border-radius: var(--radius-sm);
    border: 1px solid rgba(6, 182, 212, 0.2);
    font-weight: 600;
}

/* Zone Gameplay Arena */
.game-arena {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px;
    box-shadow: var(--shadow-subtle);
    backdrop-filter: blur(16px);
}

.arena-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 16px;
    gap: 16px;
}

.arena-title-group h2 {
    font-family: var(--font-heading);
    font-size: 1.3rem;
    font-weight: 800;
    display: flex;
    align-items: center;
    gap: 10px;
}

.arena-mode-selector {
    display: flex;
    gap: 6px;
    background: rgba(0, 0, 0, 0.3);
    padding: 4px;
    border-radius: var(--radius-md);
    overflow-x: auto;
    max-width: 100%;
}

.mode-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 8px 12px;
    font-size: 0.82rem;
    font-weight: 600;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: var(--transition);
    white-space: nowrap;
    touch-action: manipulation;
}

.mode-btn.active {
    background: var(--copper-gold);
    color: #000;
}

/* Gameplay Container */
.scenario-box {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.dialogue-card {
    background: rgba(0, 0, 0, 0.25);
    border: 1px solid var(--border-color);
    border-left: 4px solid var(--cyan-accent);
    padding: 16px;
    border-radius: var(--radius-md);
    display: flex;
    gap: 14px;
    align-items: flex-start;
}

.avatar {
    width: 44px;
    height: 44px;
    border-radius: var(--radius-full);
    background: linear-gradient(135deg, #3b82f6, #8b5cf6);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.3rem;
    flex-shrink: 0;
    box-shadow: 0 0 12px rgba(59, 130, 246, 0.3);
}

.dialogue-content {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.speaker-name {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--cyan-accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.speech-text {
    font-size: 0.98rem;
    line-height: 1.5;
    color: var(--text-primary);
}

.speech-translation {
    font-size: 0.82rem;
    color: var(--text-muted);
    font-style: italic;
}

/* Choices Grid */
.options-grid {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.option-card {
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid var(--border-color);
    padding: 14px 16px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 12px;
    font-size: 0.92rem;
    text-align: left;
    color: var(--text-primary);
    touch-action: manipulation;
}

.option-card:hover {
    background: rgba(6, 182, 212, 0.08);
    border-color: var(--cyan-accent);
}

.option-card .key-badge {
    width: 26px;
    height: 26px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.08);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--text-secondary);
    flex-shrink: 0;
}

.option-card.correct {
    background: rgba(16, 185, 129, 0.15) !important;
    border-color: var(--emerald-success) !important;
    color: #fff;
}

.option-card.correct .key-badge {
    background: var(--emerald-success);
    color: #000;
}

.option-card.incorrect {
    background: rgba(244, 63, 94, 0.15) !important;
    border-color: var(--rose-error) !important;
}

.option-card.incorrect .key-badge {
    background: var(--rose-error);
    color: #fff;
}

/* Feedback Explanation Box */
.feedback-box {
    background: rgba(15, 23, 42, 0.95);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 16px 18px;
    display: none;
    flex-direction: column;
    gap: 10px;
    animation: slideUp 0.25s ease-out forwards;
}

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

.feedback-box.show {
    display: flex;
}

.feedback-header {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-heading);
    font-size: 1rem;
    font-weight: 700;
}

.feedback-header.success { color: var(--emerald-success); }
.feedback-header.error { color: var(--rose-error); }

.grammar-tip {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.5;
    background: rgba(255, 255, 255, 0.03);
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    border-left: 3px solid var(--copper-gold);
}

.next-btn {
    align-self: flex-end;
    background: linear-gradient(135deg, var(--copper-gold), #d97706);
    color: #000;
    font-family: var(--font-heading);
    font-weight: 800;
    font-size: 0.9rem;
    border: none;
    padding: 10px 20px;
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 15px var(--gold-glow);
    touch-action: manipulation;
}

.next-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(245, 158, 11, 0.4);
}

/* Unscramble Game Mode */
.unscramble-container {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.target-prompt {
    font-size: 0.95rem;
    color: var(--text-secondary);
    background: rgba(0, 0, 0, 0.2);
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
}

.sentence-dropzone {
    min-height: 58px;
    background: rgba(0, 0, 0, 0.4);
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-md);
    padding: 10px;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
    transition: var(--transition);
}

.word-bank {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    padding: 8px 0;
}

.word-chip {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 8px 14px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    user-select: none;
    touch-action: manipulation;
}

.word-chip:hover {
    border-color: var(--copper-gold);
    background: var(--bg-card-hover);
}

.word-chip.used {
    opacity: 0.3;
    cursor: not-allowed;
}

/* Matching Game Mode - Responsive 2 Columns */
.matching-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

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

.match-card {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    padding: 12px 14px;
    border-radius: var(--radius-md);
    cursor: pointer;
    font-size: 0.88rem;
    line-height: 1.3;
    transition: var(--transition);
    touch-action: manipulation;
}

.match-card:hover {
    border-color: var(--cyan-accent);
    background: rgba(6, 182, 212, 0.08);
}

.match-card.selected {
    border-color: var(--copper-gold);
    background: rgba(245, 158, 11, 0.15);
    box-shadow: 0 0 12px var(--gold-glow);
}

.match-card.matched {
    border-color: var(--emerald-success);
    background: rgba(16, 185, 129, 0.15);
    opacity: 0.6;
    pointer-events: none;
}

/* Grammar & Vault Grids */
.grammar-vault-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
}

.vault-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 18px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    backdrop-filter: blur(12px);
    transition: var(--transition);
}

.vault-card-title {
    font-family: var(--font-heading);
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--copper-gold);
    display: flex;
    align-items: center;
    gap: 8px;
}

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

.vault-item {
    background: rgba(0, 0, 0, 0.2);
    border: 1px solid var(--border-color);
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    line-height: 1.4;
}

.external-links-banner {
    background: linear-gradient(135deg, rgba(6, 182, 212, 0.1), rgba(139, 92, 246, 0.1));
    border: 1px solid rgba(6, 182, 212, 0.3);
    border-radius: var(--radius-lg);
    padding: 18px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    margin-top: 16px;
}

.link-btn {
    background: var(--cyan-accent);
    color: #000;
    text-decoration: none;
    font-weight: 700;
    padding: 8px 16px;
    border-radius: var(--radius-md);
    font-size: 0.85rem;
    transition: var(--transition);
    white-space: nowrap;
    touch-action: manipulation;
}

/* Badges Grid */
.badges-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px;
}

.badge-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 16px;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    gap: 8px;
    opacity: 0.4;
    filter: grayscale(1);
    transition: var(--transition);
}

.badge-item.unlocked {
    opacity: 1;
    filter: grayscale(0);
    border-color: var(--copper-gold);
    box-shadow: 0 0 15px var(--gold-glow);
}

.badge-icon-wrap {
    font-size: 2rem;
    width: 52px;
    height: 52px;
    border-radius: var(--radius-full);
    background: rgba(255, 255, 255, 0.05);
    display: flex;
    align-items: center;
    justify-content: center;
}

.badge-name {
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: 0.88rem;
}

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

/* Footer */
footer.app-footer {
    border-top: 1px solid var(--border-color);
    padding: 16px;
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: auto;
}

/* RESPONSIVE MEDIA QUERIES (TABLETS & MOBILE SMARTPHONES) */
@media (max-width: 840px) {
    header.app-header {
        flex-direction: column;
        align-items: stretch;
        padding: 14px 16px;
        gap: 12px;
    }

    .brand-title {
        justify-content: center;
    }

    .user-stats-bar {
        justify-content: space-around;
        width: 100%;
    }

    .header-actions {
        justify-content: center;
        width: 100%;
    }

    .app-layout {
        padding: 14px;
        gap: 16px;
    }

    .arena-header {
        flex-direction: column;
        align-items: stretch;
    }

    .arena-mode-selector {
        width: 100%;
        justify-content: flex-start;
    }

    .nav-tab-btn {
        min-width: 150px;
        padding: 10px 14px;
        font-size: 0.85rem;
    }

    .carousel-arrow {
        width: 32px;
        height: 38px;
        font-size: 0.95rem;
    }

    .external-links-banner {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
    }

    .external-links-banner div:last-child {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .brand-text h1 {
        font-size: 1.1rem;
    }

    .stat-badge {
        padding: 4px 8px;
        font-size: 0.75rem;
    }

    .stat-badge .icon {
        font-size: 0.9rem;
    }

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

    .matching-grid {
        grid-template-columns: 1fr 1fr;
        gap: 6px;
    }

    .match-card {
        font-size: 0.78rem;
        padding: 8px 10px;
    }

    .dialogue-card {
        padding: 12px;
        gap: 10px;
    }

    .avatar {
        width: 36px;
        height: 36px;
        font-size: 1.1rem;
    }

    .speech-text {
        font-size: 0.9rem;
    }

    .option-card {
        padding: 10px 12px;
        font-size: 0.85rem;
    }

    .word-chip {
        padding: 6px 10px;
        font-size: 0.82rem;
    }

    .game-arena {
        padding: 16px;
    }

    #phrasal-search-input {
        min-width: 100% !important;
        width: 100%;
    }
}