:root {
    --primary: #6c5ce7;
    --primary-dark: #5649c0;
    --primary-light: #a29bfe;
    --primary-bg: #ede9fe;
    --accent: #00cec9;
    --bg: #f5f6fa;
    --text: #2d3436;
    --success: #00b894;
    --success-bg: #e6fffa;
    --error: #d63031;
    --error-bg: #ffebee;
    --card-bg: #ffffff;
    --border-inactive: #dfe6e9;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    margin: 0;
    padding: 20px;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

.container {
    background: var(--card-bg);
    border-radius: 20px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
    width: 100%;
    max-width: 750px;
    padding: 30px;
    text-align: center;
}

h1 {
    color: var(--primary);
    margin-bottom: 20px;
    font-size: 1.8rem;
}

.settings-group {
    margin-bottom: 25px;
    text-align: left;
    background: #f8f9fa;
    padding: 20px;
    border-radius: 15px;
    border: 1px solid #eee;
}

label.section-title {
    display: block;
    margin-bottom: 15px;
    font-weight: 700;
    color: var(--text);
    font-size: 1.1rem;
}

select {
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid #ddd;
    font-size: 1rem;
    margin-bottom: 10px;
    box-sizing: border-box;
}

.table-selection {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(70px, 1fr));
    gap: 12px;
    margin-top: 10px;
}

.table-tile {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 15px 5px;
    background: #fff;
    border: 2px solid var(--border-inactive);
    border-radius: 12px;
    cursor: pointer;
    font-weight: bold;
    font-size: 1.2rem;
    transition: all 0.2s;
    color: var(--text);
    user-select: none;
}

.table-tile.selected {
    background: var(--primary-bg);
    border-color: var(--primary);
    color: var(--primary-dark);
    transform: scale(1.05);
    box-shadow: 0 4px 8px rgba(108, 92, 231, 0.25);
}

.table-tile:hover:not(.selected) {
    border-color: var(--primary-light);
    background: #f8f6ff;
}

.checkbox-wrapper {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-top: 15px;
    padding: 10px;
    background: #fff;
    border-radius: 8px;
    border: 1px solid #eee;
}

input[type="checkbox"] {
    width: 22px;
    height: 22px;
    cursor: pointer;
    accent-color: var(--primary);
}

.toggle-all-btn {
    background: transparent;
    color: var(--primary);
    border: 2px dashed var(--primary);
    padding: 8px 15px;
    font-size: 0.9rem;
    border-radius: 20px;
    cursor: pointer;
    width: auto;
    display: inline-block;
    margin-bottom: 15px;
    font-weight: 600;
    transition: all 0.2s;
}

.toggle-all-btn:hover {
    background: var(--primary-bg);
}

.toggle-all-btn.deselect-mode {
    border-color: var(--error);
    color: var(--error);
}

.toggle-all-btn.deselect-mode:hover {
    background: #ffebee;
}

.toggle-all-btn.hidden {
    display: none;
}

button.primary-btn {
    background-color: var(--primary);
    color: white;
    border: none;
    padding: 16px 30px;
    font-size: 1.2rem;
    border-radius: 50px;
    cursor: pointer;
    width: 100%;
    font-weight: bold;
    transition: transform 0.1s, background-color 0.2s;
    margin-top: 15px;
    box-shadow: 0 4px 15px rgba(108, 92, 231, 0.3);
}

button.primary-btn:hover {
    background-color: var(--primary-dark);
    transform: translateY(-2px);
}

button.cancel-btn {
    background-color: transparent;
    color: var(--error);
    border: 2px solid var(--error);
    padding: 12px 25px;
    font-size: 1rem;
    border-radius: 50px;
    cursor: pointer;
    width: 100%;
    font-weight: bold;
    transition: all 0.2s;
    margin-top: 10px;
}

button.cancel-btn:hover {
    background-color: var(--error-bg);
    color: var(--error);
}

.game-screen, .result-screen {
    display: none;
}

.question-counter {
    font-size: 0.9rem;
    color: #666;
    margin-bottom: 5px;
}

.question-box {
    font-size: 3.5rem;
    font-weight: bold;
    margin: 30px 0;
    color: var(--primary);
    line-height: 1.2;
}

.options-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
    margin-top: 20px;
}

.option-btn {
    background-color: var(--primary-light);
    color: white;
    padding: 20px;
    font-size: 1.6rem;
    border-radius: 15px;
    border: none;
    cursor: pointer;
    transition: transform 0.1s;
}

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

.option-btn.correct {
    background-color: var(--success);
    animation: pulse 0.5s;
}

.option-btn.wrong {
    background-color: var(--error);
    animation: shake 0.5s;
}

.input-answer {
    font-size: 2.5rem;
    text-align: center;
    padding: 10px;
    border: 3px solid var(--primary);
    border-radius: 15px;
    width: 180px;
    margin: 0 auto;
    display: block;
    outline: none;
    transition: all 0.3s;
}

.input-answer.correct {
    background-color: var(--success-bg);
    border-color: var(--success);
    box-shadow: 0 0 20px var(--success);
    animation: successPulse 0.5s;
}

.input-answer.wrong {
    background-color: var(--error-bg);
    border-color: var(--error);
    box-shadow: 0 0 20px var(--error);
    animation: errorFlash 0.5s;
}

.input-answer:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px rgba(0, 206, 201, 0.2);
}

.numeric-keyboard {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    max-width: 300px;
    margin: 15px auto 0;
}

.num-key {
    background: var(--primary-light);
    color: white;
    border: none;
    padding: 15px;
    font-size: 1.5rem;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.1s;
    font-weight: bold;
}

.num-key:active {
    transform: scale(0.95);
    background: var(--primary);
}

.num-key.clear {
    background: var(--error);
}

.num-key.enter {
    background: var(--success);
    grid-column: span 3;
}

.progress-container {
    width: 100%;
    background-color: #eee;
    border-radius: 10px;
    margin-bottom: 20px;
    height: 12px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: var(--accent);
    width: 0%;
    transition: width 0.3s ease;
}

.chart-container {
    position: relative;
    width: 220px;
    height: 220px;
    margin: 20px auto;
}

.result-text {
    font-size: 1.6rem;
    margin: 20px 0;
    font-weight: bold;
    color: var(--primary);
}

#feedback-msg {
    color: #666;
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.selected-tables-info {
    background: var(--primary-bg);
    padding: 12px;
    border-radius: 8px;
    margin-top: 10px;
    font-size: 0.95rem;
    color: var(--primary-dark);
    font-weight: 600;
    border-left: 4px solid var(--primary);
}

.selected-tables-info.empty {
    background: #ffebee;
    color: var(--error);
    border-left-color: var(--error);
}

.advanced-section {
    display: none;
    margin-top: 15px;
    padding-top: 15px;
    border-top: 1px dashed #ccc;
}

.advanced-section.active {
    display: block;
    animation: fadeIn 0.3s;
}

.advanced-card {
    background: #fff;
    padding: 15px;
    border-radius: 10px;
    border: 1px solid #eee;
    margin-top: 10px;
}

.advanced-card-title {
    color: var(--primary);
    font-weight: bold;
    margin-bottom: 10px;
    font-size: 0.95rem;
}

.error-summary {
    background: #fff;
    border: 2px solid var(--error);
    border-radius: 10px;
    padding: 15px;
    margin: 20px auto;
    max-width: 500px;
    text-align: left;
}

.error-summary h3 {
    color: var(--error);
    margin: 0 0 10px 0;
    font-size: 1.1rem;
}

.error-item {
    padding: 8px;
    border-bottom: 1px solid #eee;
    font-size: 1rem;
}

.error-item:last-child {
    border-bottom: none;
}

.error-question {
    font-weight: bold;
    color: var(--text);
}

.error-wrong {
    color: var(--error);
    margin-left: 10px;
}

.error-correct {
    color: var(--success);
    margin-left: 5px;
}

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

@keyframes pulse {
    0% { transform: scale(1); }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

@keyframes successPulse {
    0% { transform: scale(1); box-shadow: 0 0 0 var(--success); }
    50% { transform: scale(1.05); box-shadow: 0 0 20px var(--success); }
    100% { transform: scale(1); box-shadow: 0 0 0 var(--success); }
}

@keyframes errorFlash {
    0%, 100% { transform: translateX(0); background-color: var(--error-bg); box-shadow: 0 0 0 var(--error); }
    25% { transform: translateX(-5px); box-shadow: 0 0 20px var(--error); }
    50% { transform: translateX(5px); box-shadow: 0 0 20px var(--error); }
    75% { transform: translateX(-5px); box-shadow: 0 0 20px var(--error); }
}

@media (max-width: 480px) {
    .container { padding: 20px; }
    h1 { font-size: 1.5rem; }
    .question-box { font-size: 2.5rem; }
    .option-btn { font-size: 1.3rem; padding: 15px; }
    .table-tile { font-size: 1rem; padding: 12px 4px; }
    .table-selection { grid-template-columns: repeat(auto-fill, minmax(55px, 1fr)); }
    .input-answer { font-size: 2rem; width: 150px; }
    .num-key { padding: 12px; font-size: 1.3rem; }
}