@import url('https://fonts.googleapis.com/css2?family=Fredoka+One&family=Nunito:wght@400;600;700;800&display=swap');

:root {
    --color-primary:   #2E7D32;
    --color-secondary: #F9A825;
    --color-accent:    #1565C0;
    --color-bg:        #F1F8E9;
    --color-card:      #FFFFFF;
    --color-text:      #1B1B1B;
    --color-muted:     #5D6D5E;
    --color-danger:    #C62828;
    --radius-sm:       8px;
    --radius-lg:       16px;
    --shadow-card:     0 4px 16px rgba(0,0,0,0.10);
    --shadow-hover:    0 8px 28px rgba(0,0,0,0.15);
    --font-body:       'Nunito', system-ui, sans-serif;
    --font-display:    'Fredoka One', 'Nunito', system-ui, sans-serif;
    --transition:      0.2s ease;
}

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

html { scroll-behavior: smooth; }

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

/* ── Nav ── */
.site-nav {
    background: var(--color-primary);
    color: #fff;
    padding: 0.75rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    flex-wrap: wrap;
    box-shadow: 0 2px 8px rgba(0,0,0,0.18);
    position: sticky;
    top: 0;
    z-index: 100;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-family: var(--font-display);
    font-size: 1.4rem;
    color: #fff;
    text-decoration: none;
}

.nav-brand svg { width: 36px; height: 36px; }

.nav-controls {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

/* ── Grade pills ── */
.grade-pills {
    display: flex;
    gap: 0.35rem;
    flex-wrap: wrap;
}

.grade-pill {
    background: rgba(255,255,255,0.18);
    color: #fff;
    border: 2px solid rgba(255,255,255,0.35);
    border-radius: 999px;
    padding: 0.25rem 0.75rem;
    font-family: var(--font-body);
    font-weight: 700;
    font-size: 0.9rem;
    cursor: pointer;
    transition: var(--transition);
}

.grade-pill:hover,
.grade-pill.active {
    background: var(--color-secondary);
    border-color: var(--color-secondary);
    color: #1B1B1B;
}

/* ── Icon buttons ── */
.icon-btn {
    background: rgba(255,255,255,0.18);
    border: none;
    border-radius: 50%;
    width: 38px;
    height: 38px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: #fff;
    font-size: 1.1rem;
    transition: var(--transition);
}

.icon-btn:hover { background: rgba(255,255,255,0.32); }

/* ── XP bar ── */
.xp-bar-wrap {
    background: var(--color-primary);
    padding: 0.4rem 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-size: 0.85rem;
    color: rgba(255,255,255,0.9);
    font-weight: 700;
}

.xp-bar-track {
    flex: 1;
    max-width: 300px;
    height: 10px;
    background: rgba(255,255,255,0.25);
    border-radius: 999px;
    overflow: hidden;
}

.xp-bar-fill {
    height: 100%;
    background: var(--color-secondary);
    border-radius: 999px;
    transition: width 0.5s ease;
    width: 0%;
}

/* ── Main content ── */
.main-content { padding: 2rem 1.5rem; max-width: 1100px; margin: 0 auto; }

/* ── Hero ── */
.hero {
    text-align: center;
    padding: 2.5rem 1rem 2rem;
}

.hero-title {
    font-family: var(--font-display);
    font-size: clamp(2rem, 5vw, 3.2rem);
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.hero-tagline {
    font-size: 1.2rem;
    color: var(--color-muted);
    font-weight: 600;
}

.mascot-svg {
    width: clamp(100px, 18vw, 160px);
    margin: 0 auto 1rem;
    display: block;
}

/* ── Grade filter bar ── */
.grade-filter {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    margin: 1.5rem 0;
}

.grade-filter-btn {
    background: var(--color-card);
    border: 2px solid #c8e6c9;
    border-radius: 999px;
    padding: 0.4rem 1.1rem;
    font-weight: 700;
    font-size: 0.95rem;
    cursor: pointer;
    transition: var(--transition);
    color: var(--color-text);
}

.grade-filter-btn:hover,
.grade-filter-btn.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: #fff;
}

/* ── Game cards ── */
.game-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 1.25rem;
    margin-top: 1rem;
}

.game-card {
    background: var(--color-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 1.25rem 1rem 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.game-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-hover);
}

.game-card-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.game-card-name {
    font-family: var(--font-display);
    font-size: 1.05rem;
    color: var(--color-primary);
    margin-bottom: 0.3rem;
}

.game-card-topic {
    font-size: 0.78rem;
    color: var(--color-muted);
    background: #e8f5e9;
    border-radius: 999px;
    padding: 0.15rem 0.6rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.game-card-stars {
    color: var(--color-secondary);
    font-size: 0.95rem;
    margin-bottom: 0.75rem;
}

.grade-badges {
    display: flex;
    gap: 0.25rem;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 0.75rem;
}

.grade-badge {
    background: #e3f2fd;
    color: var(--color-accent);
    border-radius: 999px;
    padding: 0.1rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 700;
}

.play-btn {
    display: inline-block;
    background: var(--color-primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.5rem 1.3rem;
    font-family: var(--font-display);
    font-size: 1rem;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    margin-top: auto;
}

.play-btn:hover { background: #1b5e20; transform: scale(1.04); }

/* ── Game wrapper ── */
.game-wrapper {
    max-width: 860px;
    margin: 1.5rem auto;
    background: var(--color-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    overflow: hidden;
}

.game-header {
    background: var(--color-primary);
    color: #fff;
    padding: 0.65rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
}

.game-title-text {
    font-family: var(--font-display);
    font-size: 1.1rem;
}

.game-stats {
    display: flex;
    gap: 1rem;
    align-items: center;
    font-weight: 700;
    font-size: 0.95rem;
}

.canvas-container {
    position: relative;
    width: 100%;
    aspect-ratio: 8 / 5;
    max-height: 500px;
}

canvas#game-canvas {
    width: 100%;
    height: 100%;
    display: block;
    background: #e8f5e9;
}

#game-ui-overlay {
    position: absolute;
    inset: 0;
    pointer-events: none;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

#game-ui-overlay.active { pointer-events: all; }

/* ── Results page ── */
.results-card {
    max-width: 520px;
    margin: 3rem auto;
    background: var(--color-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 2.5rem 2rem;
    text-align: center;
}

.results-title {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: 0.5rem;
}

.results-score { font-size: 3rem; font-weight: 800; color: var(--color-secondary); }

.stars-row {
    display: flex;
    justify-content: center;
    gap: 0.5rem;
    font-size: 2.5rem;
    margin: 1rem 0;
}

.star { opacity: 0; transform: scale(0.3); display: inline-block; }

.results-actions {
    display: flex;
    gap: 0.75rem;
    justify-content: center;
    flex-wrap: wrap;
    margin-top: 1.5rem;
}

.btn-secondary {
    background: #e8f5e9;
    color: var(--color-primary);
    border: 2px solid #c8e6c9;
    border-radius: var(--radius-sm);
    padding: 0.5rem 1.2rem;
    font-family: var(--font-display);
    font-size: 1rem;
    cursor: pointer;
    text-decoration: none;
    transition: var(--transition);
}

.btn-secondary:hover { background: #c8e6c9; }

/* ── Teacher dashboard ── */
.teacher-wrap {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1.5rem;
}

.teacher-login {
    max-width: 360px;
    margin: 5rem auto;
    background: var(--color-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-card);
    padding: 2rem;
    text-align: center;
}

.form-group { text-align: left; margin-bottom: 1rem; }
.form-group label { display: block; font-weight: 700; margin-bottom: 0.3rem; }
.form-group input {
    width: 100%;
    padding: 0.6rem 0.9rem;
    border: 2px solid #ccc;
    border-radius: var(--radius-sm);
    font-family: var(--font-body);
    font-size: 1rem;
}
.form-group input:focus { outline: none; border-color: var(--color-primary); }

.btn-primary {
    display: inline-block;
    background: var(--color-primary);
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    padding: 0.65rem 1.5rem;
    font-family: var(--font-display);
    font-size: 1rem;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    width: 100%;
}
.btn-primary:hover { background: #1b5e20; }

/* ── Leaderboard ── */
.leaderboard-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
}
.leaderboard-table th,
.leaderboard-table td {
    padding: 0.6rem 0.8rem;
    text-align: left;
    border-bottom: 1px solid #e0e0e0;
}
.leaderboard-table th { font-weight: 800; color: var(--color-muted); font-size: 0.85rem; }
.leaderboard-table tr:first-child td { font-weight: 700; color: var(--color-primary); }

/* ── Alert ── */
.alert {
    padding: 0.75rem 1rem;
    border-radius: var(--radius-sm);
    margin-bottom: 1rem;
    font-weight: 600;
}
.alert-error { background: #ffebee; color: var(--color-danger); border: 1px solid #ffcdd2; }
.alert-success { background: #e8f5e9; color: var(--color-primary); border: 1px solid #c8e6c9; }

/* ── Screen reader only ── */
.sr-only {
    position: absolute;
    width: 1px; height: 1px;
    padding: 0; margin: -1px;
    overflow: hidden;
    clip: rect(0,0,0,0);
    white-space: nowrap;
    border: 0;
}

/* ── Responsive ── */
@media (max-width: 600px) {
    .main-content { padding: 1rem; }
    .game-grid { grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 0.75rem; }
    .game-header { flex-wrap: wrap; }
}