/* Word Bingo - Main Stylesheet */
:root {
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-secondary: #10b981;
    --color-secondary-hover: #059669;
    --color-accent: #f59e0b;
    --color-accent-hover: #d97706;
    --color-bg: #f3f4f6;
    --color-surface: #ffffff;
    --color-surface-alt: #f9fafb;
    --color-text: #1f2937;
    --color-muted: #6b7280;
    --color-border: #e5e7eb;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.5;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Navigation Bar */
.app-nav {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: 0.75rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-left {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: var(--color-text);
    font-weight: 800;
    font-size: 1.15rem;
}

.nav-logo {
    font-size: 1.4rem;
}

.nav-separator {
    color: var(--color-muted);
    font-weight: 300;
}

.nav-current-page {
    font-weight: 600;
    color: var(--color-primary);
    font-size: 0.95rem;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.nav-home-btn {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    text-decoration: none;
    color: var(--color-muted);
    font-size: 0.88rem;
    font-weight: 600;
    padding: 0.4rem 0.8rem;
    border-radius: 8px;
    background: var(--color-surface-alt);
    border: 1px solid var(--color-border);
    transition: all 0.2s;
}

.nav-home-btn:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    background: #eff6ff;
}

.lang-selector {
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.lang-buttons {
    display: flex;
    gap: 0.3rem;
    background: var(--color-surface-alt);
    padding: 0.2rem;
    border-radius: 8px;
    border: 1px solid var(--color-border);
}

.lang-btn {
    display: flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.25rem 0.5rem;
    text-decoration: none;
    color: var(--color-muted);
    font-size: 0.78rem;
    font-weight: 700;
    border-radius: 6px;
    transition: all 0.15s;
}

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

.lang-btn.active {
    background: var(--color-primary);
    color: white;
}

/* Landing Page Styles */
.landing-container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 2.5rem 1.5rem;
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 2.5rem;
}

.hero-header {
    text-align: center;
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.2rem);
    font-weight: 900;
    color: #111827;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

.hero-subtitle {
    font-size: 1.15rem;
    color: var(--color-muted);
    margin-top: 0.5rem;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
}

/* Kids Learning Hero Card (Giant button) */
.student-section {
    display: flex;
    flex-direction: column;
}

.section-label {
    font-size: 0.85rem;
    font-weight: 800;
    text-transform: uppercase;
    letter-spacing: 0.06em;
    color: var(--color-muted);
    margin-bottom: 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

/* 4 Quiz Options Grid for Kids */
.quiz-options-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 1.25rem;
    margin-bottom: 1rem;
}

@media (min-width: 860px) {
    .quiz-options-grid {
        grid-template-columns: repeat(4, 1fr);
    }
}

@media (max-width: 540px) {
    .quiz-options-grid {
        grid-template-columns: 1fr;
    }
}

.quiz-card {
    border-radius: var(--radius-lg);
    padding: 1.5rem 1.25rem;
    color: white;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    min-height: 220px;
    box-shadow: var(--shadow-md);
    transition: transform 0.2s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.2s;
    position: relative;
    overflow: hidden;
    cursor: pointer;
}

.quiz-card:hover {
    transform: translateY(-5px) scale(1.02);
    box-shadow: var(--shadow-xl);
}

.quiz-card-1 {
    background: linear-gradient(145deg, #f59e0b 0%, #d97706 100%);
}

.quiz-card-2 {
    background: linear-gradient(145deg, #f97316 0%, #ea580c 100%);
}

.quiz-card-3 {
    background: linear-gradient(145deg, #8b5cf6 0%, #6d28d9 100%);
}

.quiz-card-4 {
    background: linear-gradient(145deg, #3b82f6 0%, #1d4ed8 100%);
}

.quiz-card-visual {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 2rem;
    margin-bottom: 0.65rem;
    background: rgba(255, 255, 255, 0.22);
    backdrop-filter: blur(4px);
    padding: 0.4rem 0.75rem;
    border-radius: 12px;
    width: fit-content;
}

.quiz-arrow {
    font-size: 1.2rem;
    opacity: 0.8;
}

.quiz-card-title {
    font-size: 1.25rem;
    font-weight: 900;
    margin-bottom: 0.25rem;
    line-height: 1.2;
}

.quiz-card-subtitle {
    font-size: 0.88rem;
    font-weight: 700;
    opacity: 0.95;
    margin-bottom: 0.5rem;
}

.quiz-card-desc {
    font-size: 0.82rem;
    opacity: 0.9;
    line-height: 1.35;
    margin-bottom: 1rem;
}

.quiz-card-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.4rem;
    background: white;
    padding: 0.65rem 1rem;
    border-radius: 12px;
    font-weight: 800;
    font-size: 0.92rem;
    margin-top: auto;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.quiz-card-1 .quiz-card-btn { color: #b45309; }
.quiz-card-2 .quiz-card-btn { color: #c2410c; }
.quiz-card-3 .quiz-card-btn { color: #5b21b6; }
.quiz-card-4 .quiz-card-btn { color: #1e40af; }

.kid-title {
    font-size: clamp(2rem, 4.5vw, 2.8rem);
    font-weight: 900;
    line-height: 1.15;
    margin-bottom: 0.6rem;
    text-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.kid-desc {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.95);
    line-height: 1.45;
}

.kid-btn-action {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    background: white;
    color: #065f46;
    font-size: 1.3rem;
    font-weight: 800;
    padding: 1.2rem 2.2rem;
    border-radius: 18px;
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
    flex-shrink: 0;
    margin-left: 1.5rem;
    z-index: 2;
}

/* Teacher Tools Section */
.teacher-section {
    display: flex;
    flex-direction: column;
}

.teacher-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.teacher-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 1.8rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.teacher-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-md);
    border-color: #cbd5e1;
}

.teacher-card-header {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    margin-bottom: 1rem;
}

.teacher-icon {
    font-size: 2.2rem;
    background: #eff6ff;
    width: 3.5rem;
    height: 3.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    flex-shrink: 0;
}

.teacher-card-title {
    font-size: 1.3rem;
    font-weight: 800;
    color: #1e293b;
    margin-bottom: 0.35rem;
}

.teacher-card-desc {
    font-size: 0.92rem;
    color: var(--color-muted);
    line-height: 1.5;
}

.teacher-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    font-weight: 700;
    font-size: 0.95rem;
    padding: 0.85rem 1.4rem;
    border-radius: var(--radius-md);
    transition: background 0.2s, transform 0.1s;
    margin-top: 1.25rem;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
}

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

.btn-secondary {
    background: #3b82f6;
    color: white;
}

.btn-secondary:hover {
    background: #2563eb;
}

/* Footer */
.app-footer {
    text-align: center;
    padding: 1.5rem;
    font-size: 0.85rem;
    color: var(--color-muted);
    border-top: 1px solid var(--color-border);
    background: var(--color-surface);
}

/* Responsive adjustments */
@media (max-width: 820px) {
    .kid-hero-card {
        flex-direction: column;
        align-items: flex-start;
        padding: 2rem 1.5rem;
        gap: 1.5rem;
    }
    .kid-btn-action {
        margin-left: 0;
        width: 100%;
        justify-content: center;
    }
    .teacher-grid {
        grid-template-columns: 1fr;
    }
}

@media print {
    .app-nav, .app-footer, .button-container {
        display: none !important;
    }
}