/* ═══════════════════════════════════════════════════════════════
   READING FOCUS — Research-based sight word & reading skills game
   Design principles:
   • Lexend Deca font — reduces visual noise, improves reading speed
   • High contrast, minimal decoration during active reading
   • Large touch targets (≥72px) for kids and tablets
   • Warm cream background — less glare than white
   • Positive-only feedback design (no failure sounds/colors)
═══════════════════════════════════════════════════════════════ */

:root {
    --bg:          #fffdf0;
    --text:        #1a1a2e;
    --text-light:  #5a5a7a;
    --card:        #ffffff;
    --border:      #e8e4d4;

    --mode-1: #ff6b6b;   /* Sight Snap   — coral */
    --mode-2: #2563eb;   /* Word Rain    — blue  */
    --mode-3: #16a34a;   /* Story Fill   — green */
    --mode-4: #ffd166;   /* Word Sort    — gold */

    --success:  #16a34a;
    --error:    #ef476f;
    --locked:   #c5c5d5;

    --radius-sm: 10px;
    --radius-md: 18px;
    --radius-lg: 28px;
    --radius-xl: 50px;
    --shadow:    0 4px 20px rgba(26,26,46,0.10);
    --shadow-lg: 0 8px 32px rgba(26,26,46,0.15);
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { height: 100%; }

body {
    font-family: 'Lexend Deca', system-ui, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    min-height: 100vh;
    letter-spacing: 0.03em;
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
}

/* ─── Screen System ───────────────────────────────────────────── */
.screen {
    display: none;
    flex-direction: column;
    align-items: center;
    width: 100%;
    padding: 24px 16px 40px;
    animation: fadeIn 0.2s ease;
}
.screen.active { display: flex; }

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

/* ─── Home Screen ─────────────────────────────────────────────── */
.home-header {
    text-align: center;
    padding: 8px 20px 0;
    max-width: 600px;
    width: 100%;
}

.home-header h1 {
    font-family: 'Fredoka One', cursive;
    font-size: clamp(2rem, 6vw, 2.8rem);
    color: #16a34a;
    text-shadow: 2px 2px 0 rgba(6,214,160,0.2);
    margin-bottom: 4px;
}

.home-tagline {
    font-size: 1rem;
    color: var(--text-light);
    margin-bottom: 12px;
}

.total-stars-display {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: #fffbe8;
    border: 2px solid #ffd166;
    border-radius: var(--radius-xl);
    padding: 5px 16px;
    font-size: 1.1rem;
    font-weight: 700;
    margin-top: 8px;
    color: #b8860b;
}

/* ─── Grade Selector ──────────────────────────────────────────── */
.grade-selector {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    margin: 20px 0 8px;
}

.grade-label {
    font-size: 0.85rem;
    color: var(--text-light);
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.grade-btns {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
    justify-content: center;
}

.grade-btn {
    padding: 8px 18px;
    background: var(--card);
    border: 2px solid var(--border);
    border-radius: var(--radius-xl);
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: 0.88rem;
    font-weight: 700;
    cursor: pointer;
    color: var(--text-light);
    transition: all 0.15s;
}

.grade-btn.active {
    background: #1a1a2e;
    border-color: #1a1a2e;
    color: #ffe66d;
}

.grade-btn:hover:not(.active) {
    border-color: #1a1a2e;
    color: #1a1a2e;
}

/* ─── Mode Grid ───────────────────────────────────────────────── */
.mode-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 16px;
    max-width: 680px;
    width: 100%;
    padding: 8px 0 8px;
}

.mode-card {
    background: var(--card);
    border-radius: var(--radius-md);
    padding: 22px 20px;
    display: flex;
    align-items: center;
    gap: 18px;
    box-shadow: var(--shadow);
    border: 2px solid transparent;
    cursor: pointer;
    transition: transform 0.15s, box-shadow 0.15s, border-color 0.15s;
    text-align: left;
}

.mode-card:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.mode-card[data-color="1"] { border-color: var(--mode-1); }
.mode-card[data-color="2"] { border-color: var(--mode-2); }
.mode-card[data-color="3"] { border-color: var(--mode-3); }
.mode-card[data-color="4"] { border-color: var(--mode-4); }

.mode-icon { font-size: 2.4rem; line-height: 1; flex-shrink: 0; }

.mode-info h3 {
    font-family: 'Fredoka One', cursive;
    font-size: 1.25rem;
    color: var(--text);
    margin-bottom: 2px;
}

.mode-info p {
    font-size: 0.82rem;
    color: var(--text-light);
    line-height: 1.45;
}

.mode-stars {
    margin-left: auto;
    font-size: 0.9rem;
    color: #ffd166;
    white-space: nowrap;
    flex-shrink: 0;
}

/* ─── Home Footer ─────────────────────────────────────────────── */
.home-footer {
    display: flex;
    gap: 16px;
    align-items: center;
    justify-content: center;
    flex-wrap: wrap;
    padding: 16px 0 0;
}

.back-link {
    color: var(--text-light);
    text-decoration: none;
    font-size: 0.88rem;
    transition: color 0.15s;
}
.back-link:hover { color: var(--text); }

.reset-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 6px 14px;
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: 0.82rem;
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.15s;
}
.reset-btn:hover { border-color: var(--error); color: var(--error); }

/* ─── Level Select Screen ─────────────────────────────────────── */
.screen-header {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    max-width: 640px;
    margin-bottom: 8px;
}

.back-btn {
    width: 44px; height: 44px;
    background: var(--card);
    border: 2px solid var(--border);
    border-radius: 50%;
    font-size: 1.3rem;
    cursor: pointer;
    flex-shrink: 0;
    color: var(--text);
    transition: all 0.15s;
    display: flex; align-items: center; justify-content: center;
}
.back-btn:hover { border-color: var(--text); }

.mode-icon-lg { font-size: 2rem; }

.screen-header h2 {
    font-family: 'Fredoka One', cursive;
    font-size: 1.5rem;
    color: var(--text);
}

.levels-desc {
    font-size: 0.88rem;
    color: var(--text-light);
    max-width: 500px;
    text-align: center;
    margin-bottom: 16px;
}

.levels-grid {
    display: grid;
    grid-template-columns: repeat(5, 1fr);
    gap: 10px;
    max-width: 400px;
    width: 100%;
}

.level-btn {
    aspect-ratio: 1;
    border-radius: var(--radius-md);
    background: var(--card);
    border: 2px solid var(--border);
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 2px;
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
    transition: all 0.15s;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}

.level-btn:hover:not(.locked) { transform: translateY(-2px); box-shadow: var(--shadow); }
.level-btn.locked { opacity: 0.4; cursor: not-allowed; }
.level-btn.completed { background: #f0fff8; border-color: var(--success); }
.level-stars { font-size: 0.65rem; color: #ffd166; }

/* ─── Game Screen ─────────────────────────────────────────────── */
.game-header {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    max-width: 640px;
    margin-bottom: 20px;
}

.quit-btn {
    width: 40px; height: 40px;
    border-radius: 50%;
    background: var(--card);
    border: 2px solid var(--border);
    font-size: 1rem;
    cursor: pointer;
    flex-shrink: 0;
    color: var(--text-light);
    display: flex; align-items: center; justify-content: center;
    transition: all 0.15s;
}
.quit-btn:hover { border-color: var(--error); color: var(--error); }

.progress-track {
    flex: 1;
    height: 10px;
    background: var(--border);
    border-radius: 10px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: linear-gradient(90deg, #16a34a, #0e7a37);
    border-radius: 10px;
    transition: width 0.4s ease;
    width: 0%;
}

.score-badge {
    background: #1a1a2e;
    color: #ffe66d;
    font-family: 'Fredoka One', cursive;
    font-size: 1.1rem;
    padding: 4px 14px;
    border-radius: var(--radius-xl);
    min-width: 52px;
    text-align: center;
}

.game-content {
    width: 100%;
    max-width: 640px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    flex: 1;
}

/* ─── Sight Snap Mode ─────────────────────────────────────────── */
.flash-word {
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: clamp(3rem, 14vw, 6rem);
    font-weight: 800;
    color: var(--text);
    letter-spacing: 0.06em;
    text-align: center;
    animation: wordPop 0.3s ease;
}
@keyframes wordPop {
    from { transform: scale(0.7); opacity: 0; }
    to   { transform: scale(1);   opacity: 1; }
}

.flash-prompt {
    font-size: 1rem;
    color: var(--text-light);
    text-align: center;
}

.flash-timer {
    width: 100%;
    max-width: 300px;
    height: 8px;
    background: var(--border);
    border-radius: 8px;
    overflow: hidden;
}
.flash-timer-bar {
    height: 100%;
    background: #ff6b6b;
    border-radius: 8px;
    transition: width linear;
    width: 100%;
}

.choices-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
    width: 100%;
    max-width: 500px;
}

.choice-btn {
    padding: 22px 16px;
    background: var(--card);
    border: 3px solid var(--border);
    border-radius: var(--radius-md);
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: clamp(1.2rem, 4vw, 1.8rem);
    font-weight: 700;
    cursor: pointer;
    color: var(--text);
    letter-spacing: 0.04em;
    transition: all 0.12s;
    text-align: center;
}
.choice-btn:hover { border-color: #a29bfe; background: #f5f3ff; transform: scale(1.02); }
.choice-btn.correct { background: #e6fff5; border-color: var(--success); color: #047857; }
.choice-btn.wrong   { background: #fff0f0; border-color: var(--error);   color: #be123c; }
.choice-btn:disabled { cursor: default; }

/* ─── Word Rain Mode ──────────────────────────────────────────── */
.rain-arena {
    width: 100%;
    max-width: 500px;
    height: 320px;
    position: relative;
    background: linear-gradient(180deg, #e8f4ff 0%, #dbeafe 100%);
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 2px solid #bfdbfe;
}

.rain-target {
    text-align: center;
    font-size: 0.88rem;
    color: var(--text-light);
    margin-bottom: 4px;
}

.rain-target strong {
    font-size: 1.4rem;
    color: var(--text);
    font-weight: 800;
    display: block;
    margin-top: 4px;
}

.falling-word {
    position: absolute;
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-weight: 700;
    font-size: 1.3rem;
    background: #fff;
    border: 2px solid var(--border);
    border-radius: 10px;
    padding: 8px 16px;
    cursor: pointer;
    transition: background 0.1s, border-color 0.1s;
    white-space: nowrap;
    user-select: none;
    letter-spacing: 0.04em;
}
.falling-word:hover { background: #f5f3ff; border-color: #a29bfe; }
.falling-word.hit-correct { background: #e6fff5; border-color: var(--success); }
.falling-word.hit-wrong   { background: #fff0f0; border-color: var(--error); }

.lives-display {
    font-size: 1.4rem;
    letter-spacing: 0.08em;
}

/* ─── Story Fill Mode ─────────────────────────────────────────── */
.sentence-box {
    background: var(--card);
    border-radius: var(--radius-md);
    padding: 28px 24px;
    font-size: clamp(1.1rem, 3.5vw, 1.4rem);
    line-height: 1.9;
    text-align: center;
    box-shadow: var(--shadow);
    border: 2px solid var(--border);
    width: 100%;
    max-width: 560px;
    letter-spacing: 0.03em;
}

.sentence-blank {
    display: inline-block;
    min-width: 80px;
    border-bottom: 3px solid #a29bfe;
    color: #a29bfe;
    font-weight: 800;
    padding: 0 4px;
    letter-spacing: 0.06em;
}

.sentence-count {
    font-size: 0.82rem;
    color: var(--text-light);
    text-align: center;
}

/* ─── Word Sort Mode ──────────────────────────────────────────── */
.sort-word-display {
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: clamp(2.5rem, 10vw, 4.5rem);
    font-weight: 800;
    color: var(--text);
    text-align: center;
    letter-spacing: 0.06em;
    animation: wordPop 0.3s ease;
}

.sort-prompt {
    font-size: 0.9rem;
    color: var(--text-light);
    text-align: center;
    max-width: 360px;
}

.sort-categories {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    width: 100%;
    max-width: 520px;
}

.sort-cat-btn {
    padding: 20px 16px;
    background: var(--card);
    border: 3px solid var(--border);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all 0.12s;
    text-align: center;
}

.sort-cat-btn:hover { transform: scale(1.02); }

.sort-cat-btn .cat-label {
    font-family: 'Fredoka One', cursive;
    font-size: 1.2rem;
    display: block;
    margin-bottom: 6px;
}

.sort-cat-btn .cat-examples {
    font-size: 0.82rem;
    color: var(--text-light);
    letter-spacing: 0.03em;
}

.sort-cat-btn.correct { background: #e6fff5; border-color: var(--success); }
.sort-cat-btn.wrong   { background: #fff0f0; border-color: var(--error); }
.sort-cat-btn:disabled { cursor: default; }

.sort-score-bar {
    display: flex;
    align-items: center;
    gap: 16px;
    font-size: 0.88rem;
    color: var(--text-light);
}

/* ─── Feedback overlay ────────────────────────────────────────── */
.game-feedback {
    position: fixed;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: var(--success);
    color: white;
    font-family: 'Fredoka One', cursive;
    font-size: 2rem;
    padding: 16px 40px;
    border-radius: var(--radius-lg);
    z-index: 300;
    pointer-events: none;
    animation: feedbackPop 0.4s ease;
}
.game-feedback.wrong-feedback { background: var(--error); }
.game-feedback.hidden { display: none; }

@keyframes feedbackPop {
    0%   { transform: translate(-50%, -50%) scale(0.6); opacity: 0; }
    60%  { transform: translate(-50%, -50%) scale(1.1); opacity: 1; }
    100% { transform: translate(-50%, -50%) scale(1);   opacity: 1; }
}

/* ─── Results Screen ──────────────────────────────────────────── */
.results-card {
    background: var(--card);
    border-radius: var(--radius-lg);
    padding: 36px 28px;
    max-width: 440px;
    width: 100%;
    text-align: center;
    box-shadow: var(--shadow-lg);
}

.results-stars {
    font-size: 2.4rem;
    margin-bottom: 12px;
    letter-spacing: 4px;
}

.results-card h2 {
    font-family: 'Fredoka One', cursive;
    font-size: 1.8rem;
    color: var(--text);
    margin-bottom: 6px;
}

.results-card p {
    font-size: 0.93rem;
    color: var(--text-light);
    margin-bottom: 20px;
    line-height: 1.55;
}

.results-stats {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 24px;
}

.stat {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: var(--bg);
    border-radius: var(--radius-md);
    padding: 12px 20px;
    min-width: 72px;
}
.stat span { font-family: 'Fredoka One', cursive; font-size: 1.6rem; color: var(--text); }
.stat label { font-size: 0.75rem; color: var(--text-light); }

.results-btns {
    display: flex;
    gap: 10px;
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: 12px;
}

.btn-primary-rf {
    padding: 12px 28px;
    background: #1a1a2e;
    color: #ffe66d;
    border: none;
    border-radius: var(--radius-xl);
    font-family: 'Fredoka One', cursive;
    font-size: 1rem;
    cursor: pointer;
    transition: filter 0.15s;
}
.btn-primary-rf:hover { filter: brightness(1.15); }

.btn-secondary-rf {
    padding: 12px 28px;
    background: #16a34a;
    color: white;
    border: none;
    border-radius: var(--radius-xl);
    font-family: 'Fredoka One', cursive;
    font-size: 1rem;
    cursor: pointer;
    transition: filter 0.15s;
}
.btn-secondary-rf:hover { filter: brightness(1.08); }

.btn-ghost-rf {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: 8px 20px;
    font-family: 'Lexend Deca', system-ui, sans-serif;
    font-size: 0.85rem;
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.15s;
}
.btn-ghost-rf:hover { border-color: var(--text); color: var(--text); }

/* ─── Responsive ──────────────────────────────────────────────── */
@media (max-width: 400px) {
    .choices-grid { grid-template-columns: 1fr 1fr; gap: 8px; }
    .choice-btn   { padding: 16px 8px; font-size: 1.1rem; }
    .levels-grid  { grid-template-columns: repeat(4, 1fr); }
    .sort-categories { grid-template-columns: 1fr; }
}