/* ===================================
   Digit Span Test Game - Main Styles
   =================================== */

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

body {
    width: 100vw;
    height: 100vh;
    font-family: 'Arial', sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

/* Game Container */
.game-container {
    width: 100%;
    height: 100%;
    max-width: 1400px;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    display: flex;
    flex-direction: column;
    position: relative;
    margin: 10px;
}

/* Progress Bar */
.progress-bar {
    padding: 20px;
    background: #f8f9fa;
    border-radius: 20px 20px 0 0;
    border-bottom: 2px solid #e9ecef;
}

.progress-grid {
    display: grid;
    grid-template-columns: repeat(20, 1fr);
    gap: 5px;
    margin-top: 10px;
}

.level-box {
    aspect-ratio: 1;
    background: #e9ecef;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
    color: #6c757d;
    transition: all 0.3s ease;
    position: relative;
}

.level-box.correct {
    background: #28a745;
    color: white;
    animation: correctPulse 0.5s ease;
}

.level-box.incorrect {
    background: #dc3545;
    color: white;
    animation: incorrectShake 0.5s ease;
}

.level-box.current {
    background: #007bff;
    color: white;
    box-shadow: 0 0 20px rgba(0, 123, 255, 0.5);
    animation: currentPulse 1s infinite;
}

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

@keyframes incorrectShake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

@keyframes currentPulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.7; }
}

/* Game Area */
.game-area {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 40px;
    position: relative;
}

/* Start Screen */
.start-screen {
    text-align: center;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

.game-title {
    font-size: 48px;
    font-weight: bold;
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 30px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

.game-rules {
    background: #f8f9fa;
    border-radius: 15px;
    padding: 30px;
    margin-bottom: 30px;
    max-width: 600px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.game-rules h2 {
    color: #495057;
    margin-bottom: 20px;
    font-size: 24px;
}

.game-rules ul {
    list-style: none;
    text-align: left;
    color: #6c757d;
    line-height: 1.8;
}

.game-rules li {
    margin-bottom: 10px;
    padding-left: 25px;
    position: relative;
}

.game-rules li:before {
    content: "🎯";
    position: absolute;
    left: 0;
}

.start-btn {
    background: linear-gradient(45deg, #28a745, #20c997);
    color: white;
    border: none;
    padding: 20px 60px;
    font-size: 24px;
    font-weight: bold;
    border-radius: 50px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 10px 25px rgba(40, 167, 69, 0.3);
}

.start-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(40, 167, 69, 0.4);
}

/* Game Screen */
.game-screen {
    display: none;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
}

.game-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: 600px;
    margin-bottom: 20px;
}

.level-indicator {
    font-size: 24px;
    color: #495057;
    font-weight: bold;
}

.score-indicator {
    display: flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: bold;
    font-size: 18px;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.3);
}

.score-label {
    opacity: 0.9;
}

.score-value {
    font-size: 24px;
    font-weight: 800;
    min-width: 40px;
    text-align: right;
}

.score-max {
    opacity: 0.8;
    font-size: 16px;
}

.timer-bar {
    width: 300px;
    height: 8px;
    background: #e9ecef;
    border-radius: 4px;
    margin-bottom: 30px;
    overflow: hidden;
}

.timer-fill {
    height: 100%;
    background: linear-gradient(90deg, #28a745, #ffc107, #dc3545);
    border-radius: 4px;
    transition: width 0.1s linear;
}

.number-display {
    font-size: 72px;
    font-weight: bold;
    color: #495057;
    margin-bottom: 30px;
    text-align: center;
    min-height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    letter-spacing: 10px;
}

.input-area {
    display: none;
    flex-direction: column;
    align-items: center;
    gap: 20px;
}

.answer-input {
    font-size: 36px;
    padding: 15px 30px;
    border: 3px solid #dee2e6;
    border-radius: 15px;
    text-align: center;
    width: 300px;
    font-weight: bold;
    letter-spacing: 5px;
    transition: all 0.3s ease;
}

.answer-input:focus {
    outline: none;
    border-color: #007bff;
    box-shadow: 0 0 20px rgba(0, 123, 255, 0.2);
}

.answer-input[aria-invalid="true"] {
    border-color: #dc3545;
}

.submit-btn {
    background: linear-gradient(45deg, #007bff, #6610f2);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 18px;
    font-weight: bold;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(0, 123, 255, 0.3);
}

.submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 123, 255, 0.4);
}

.submit-btn:disabled {
    background: #6c757d;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Result Screen */
.result-screen {
    display: none;
    text-align: center;
    animation: fadeIn 0.5s ease;
}

.result-title {
    font-size: 36px;
    font-weight: bold;
    color: #495057;
    margin-bottom: 20px;
}

.score-display {
    font-size: 64px;
    font-weight: bold;
    background: linear-gradient(45deg, #667eea, #764ba2);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 20px;
}

.performance {
    font-size: 24px;
    font-weight: bold;
    padding: 15px 30px;
    border-radius: 50px;
    margin-bottom: 30px;
    display: inline-block;
}

.performance.excellent {
    background: linear-gradient(45deg, #28a745, #20c997);
    color: white;
}

.performance.good {
    background: linear-gradient(45deg, #ffc107, #fd7e14);
    color: white;
}

.performance.normal {
    background: linear-gradient(45deg, #6c757d, #495057);
    color: white;
}

.restart-btn {
    background: linear-gradient(45deg, #17a2b8, #138496);
    color: white;
    border: none;
    padding: 15px 40px;
    font-size: 18px;
    font-weight: bold;
    border-radius: 25px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(23, 162, 184, 0.3);
}

.restart-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(23, 162, 184, 0.4);
}

/* Feedback Messages */
.feedback {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 48px;
    font-weight: bold;
    padding: 20px 40px;
    border-radius: 15px;
    animation: feedbackPop 1s ease;
    z-index: 100;
}

.feedback.correct {
    background: rgba(40, 167, 69, 0.9);
    color: white;
}

.feedback.incorrect {
    background: rgba(220, 53, 69, 0.9);
    color: white;
}

@keyframes feedbackPop {
    0% { opacity: 0; transform: translate(-50%, -50%) scale(0.5); }
    50% { opacity: 1; transform: translate(-50%, -50%) scale(1.2); }
    100% { opacity: 0; transform: translate(-50%, -50%) scale(1); }
}

/* Error Message */
.error-message {
    color: #dc3545;
    font-size: 14px;
    margin-top: 10px;
    text-align: center;
    animation: shake 0.5s ease;
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-5px); }
    75% { transform: translateX(5px); }
}

/* Responsive Design */
@media (max-width: 768px) {
    .game-container {
        margin: 5px;
        border-radius: 15px;
    }

    .game-title {
        font-size: 36px;
    }

    .game-info {
        flex-direction: column;
        gap: 15px;
        align-items: flex-start;
    }

    .score-indicator {
        font-size: 16px;
        padding: 8px 16px;
    }

    .score-value {
        font-size: 20px;
        min-width: 35px;
    }

    .score-max {
        font-size: 14px;
    }

    .progress-grid {
        gap: 3px;
    }

    .level-box {
        font-size: 10px;
    }

    .number-display {
        font-size: 48px;
        letter-spacing: 5px;
    }

    .answer-input {
        font-size: 24px;
        width: 250px;
    }
}

/* Large Screen Optimization */
@media (min-width: 1200px) {
    .game-container {
        max-width: 1600px;
        margin: 20px;
    }

    .number-display {
        font-size: 84px;
        letter-spacing: 12px;
    }

    .answer-input {
        font-size: 42px;
        width: 400px;
    }

    .level-box {
        font-size: 14px;
    }
}

/* Ultra-large Screen Optimization */
@media (min-width: 1600px) {
    .number-display {
        font-size: 96px;
        letter-spacing: 15px;
    }

    .answer-input {
        font-size: 48px;
        width: 450px;
    }
}