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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #1f2937;
    background: #f8f9fa;
    min-height: 100vh;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
    background: #e0f2fe;
    min-height: 100vh;
    box-shadow: 0 0 20px rgba(0,0,0,0.1);
}

header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 2px solid #e5e7eb;
}

header h1 {
    color: #2563eb;
    margin-bottom: 15px;
    font-size: 2.5em;
}

.instructions {
    text-align: left;
    max-width: 500px;
    margin: 0 auto;
}

.instructions p {
    color: #1f2937;
    font-size: 1.0em;
    margin-bottom: 6px;
    display: flex;
    align-items: center;
    gap: 8px;
}

.bullet {
    font-size: 1.1em;
    flex-shrink: 0;
    font-weight: bold;
}

.words-given {
    margin-bottom: 30px;
    text-align: center;
}

.words-given h3 {
    margin-bottom: 15px;
    color: #374151;
    font-size: 1.2em;
}

.word-list {
    display: flex;
    justify-content: center;
    gap: 15px;
    flex-wrap: wrap;
}

.word-chip {
    background: #3b82f6;
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 1.1em;
    letter-spacing: 1px;
}

.word-chip-detailed {
    background: #3b82f6 !important;
    padding: 8px 14px !important;
    border-radius: 20px !important;
    font-weight: bold !important;
    text-align: center !important;
    min-width: 110px !important;
    color: white !important;
}

.word-chip-detailed .letters {
    color: white !important;
    font-size: 0.9em !important;
    letter-spacing: 2px !important;
    margin-bottom: 3px !important;
    font-weight: bold !important;
}

.word-chip-detailed .values {
    /*color: #fbbf24 !important;*/
    font-size: 0.7em !important;
    letter-spacing: 2px !important;
    font-weight: normal !important;
}

.grid-container {
    display: flex;
    justify-content: center;
    margin-bottom: 15px;
}

.main-grid {
    display: grid;
    grid-template-columns: repeat(4, 60px);
    grid-template-rows: repeat(4, 60px);
    gap: 2px;
    border: 3px solid #2563eb;
    border-radius: 8px;
    padding: 8px;
    background: #f8fafc;
}

.cell {
    width: 60px;
    height: 60px;
    border: 2px solid #d1d5db;
    border-radius: 6px;
    text-align: center;
    font-size: 1.8em;
    font-weight: bold;
    text-transform: uppercase;
    background: white;
    transition: all 0.2s ease;
}

.cell:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.cell:hover {
    border-color: #6b7280;
}

.corner-cell {
    width: 60px;
    height: 60px;
    background: transparent;
}

.sum-display {
    width: 60px;
    height: 60px;
    border: 2px solid #9ca3af;
    border-radius: 6px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    background: #f3f4f6;
    color: #374151;
    font-size: 0.8em;
}

.sum-display.correct {
    border-color: #10b981;
    background: #d1fae5;
    color: #065f46;
}

.sum-display.incorrect {
    border-color: #ef4444;
    background: #fee2e2;
    color: #dc2626;
}

.letter-value-legend {
    margin-bottom: 30px;
    text-align: center;
}

.letter-value-legend h4 {
    margin-bottom: 10px;
    color: #374151;
    font-size: 1.1em;
}

.legend-grid {
    display: inline-block;
    border: 2px solid #e5e7eb;
    border-radius: 8px;
    overflow: hidden;
    background: #f8fafc;
}

.legend-row {
    display: flex;
}

.legend-row.letters {
    background: #3b82f6;
    color: white;
}

.legend-row.numbers {
    background: white;
    color: #374151;
}

.legend-row span {
    padding: 4px 6px;
    border-right: 1px solid #e5e7eb;
    text-align: center;
    font-size: 0.85em;
    font-weight: bold;
    width: 22px;
    flex-shrink: 0;
    box-sizing: border-box;
}

.legend-row span:last-child {
    border-right: none;
}

.legend-row.letters span {
    border-right-color: rgba(255, 255, 255, 0.3);
}

.legend-row.numbers span {
    border-top: 1px solid #e5e7eb;
}


/* Timer Section - Properly Centered */
.timer-section {
    text-align: center;
    margin: 0;
    padding: 10px;
    width: 100%;
}

.timer-display {
    text-align: center;
    font-size: 1.1em;
    color: #374151;
}

#timer-text {
    font-family: 'Courier New', monospace;
    color: #2563eb;
    font-size: 1.5em;
    font-weight: bold;
    margin-right: 15px;
}

#completion-message {
    color: #065f46;
    background: #d1fae5;
    padding: 8px 16px;
    border-radius: 15px;
    border: 1px solid #10b981;
    font-size: 0.95em;
    margin-left: 15px;
 }
 



.mobile-show {
    display: none;
}

.mobile-hide {
    display: inline-flex;
}

.final-word-section {
    text-align: center;
    margin-bottom: 30px;
}

.final-word-section label {
    display: block;
    margin-bottom: 15px;
    font-weight: bold;
    color: #374151;
    font-size: 1.1em;
}

#final-word {
    padding: 12px 20px;
    border: 2px solid #d1d5db;
    border-radius: 8px;
    font-size: 1em;
    text-align: center;
    text-transform: uppercase;
    letter-spacing: 2px;
    margin-right: 15px;
    width: 200px;
}

#final-word:focus {
    outline: none;
    border-color: #3b82f6;
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.word-feedback {
    margin-top: 10px;
    padding: 8px 16px;
    border-radius: 20px;
    font-weight: bold;
    font-size: 1.0em;
    text-align: center;
    min-height: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.word-feedback.success {
    background: #d1fae5;
    color: #065f46;
    border: 2px solid #10b981;
}

.word-feedback.error {
    background: #fee2e2;
    color: #dc2626;
    border: 2px solid #ef4444;
}

.word-feedback::before {
    font-size: 1.2em;
}

.word-feedback.success::before {
    content: "✓";
}

.word-feedback.error::before {
    content: "✗";
}

.action-buttons {
    margin-top: 20px;
    display: flex;
    gap: 15px;
    justify-content: center;
}

.action-buttons button {
    padding: 10px 20px;
    background: #3b82f6;
    color: #1e3a8a;
    border: 2px solid #1e3a8a;
    border-radius: 8px;
    font-size: 1.0em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 120px;
}

.action-buttons button:hover {
    background: #2563eb;
    color: #1e40af;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(59, 130, 246, 0.3);
}

.feedback {
    text-align: center;
    padding: 15px;
    border-radius: 8px;
    font-weight: bold;
    margin-bottom: 20px;
    min-height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.feedback.success {
    background: #d1fae5;
    color: #065f46;
    border: 2px solid #10b981;
}

.feedback.error {
    background: #fee2e2;
    color: #dc2626;
    border: 2px solid #ef4444;
}

.feedback.info {
    background: #dbeafe;
    color: #1e40af;
    border: 2px solid #3b82f6;
}

footer {
    display: flex;
    justify-content: center;
    gap: 20px;
    padding-top: 20px;
    border-top: 1px solid #e5e7eb;
}



@media (max-width: 600px) {
    .container {
        padding: 15px;
    }
    
    .main-grid {
        grid-template-columns: repeat(4, 50px);
        grid-template-rows: repeat(4, 50px);
    }
    
    .cell {
        width: 50px;
        height: 50px;
        font-size: 1.5em;
    }
    
    .sum-display {
        width: 50px;
        height: 50px;
        font-size: 0.7em;
    }
    
    .corner-cell {
        width: 50px;
        height: 50px;
    }
    
    .word-list {
        gap: 10px;
    }
    
    .word-chip {
        padding: 6px 12px;
        font-size: 1em;
    }
    
    .word-chip-detailed {
        padding: 6px 10px;
        min-width: 90px !important;
    }
    
    .word-chip-detailed .letters {
        font-size: 0.8em !important;
        letter-spacing: 1px !important;
    }
    
    .word-chip-detailed .values {
        font-size: 0.65em !important;
        letter-spacing: 1px !important;
    }
    
    .legend-row span {
        padding: 3px 4px;
        font-size: 0.7em;
        width: 18px;
    }
    
    .mobile-show {
        display: flex;
    }
    
    .mobile-hide {
        display: none;
    }
    
    .instructions {
        text-align: center;
    }
    
    .instructions p {
        justify-content: center;
    }
}

/* Popup Styles */
.popup-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.4);
    z-index: 9999;
    display: flex;
    align-items: center;
    justify-content: center;
}

.popup-content {
    background: white;
    border-radius: 12px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    max-width: 500px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
}

.popup-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px 0 25px;
    border-bottom: 2px solid #e5e7eb;
    margin-bottom: 20px;
}

.popup-header h3 {
    color: #2563eb;
    margin: 0;
    font-size: 1.5em;
}

.close-button {
    background: none;
    border: none;
    font-size: 2em;
    color: #6b7280;
    cursor: pointer;
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all 0.2s ease;
}

.close-button:hover {
    background: #f3f4f6;
    color: #374151;
}

.popup-body {
    padding: 0 25px 25px 25px;
}

.popup-body p {
    margin-bottom: 15px;
    color: #1f2937;
    font-size: 1.0em;
    line-height: 1.6;
}

.popup-body p:last-child {
    margin-bottom: 0;
}

/* Puzzle Navigation Styles */
.puzzle-navigation {
    margin-bottom: 20px;
    text-align: center;
}

.nav-container {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: center;
    gap: 20px;
    max-width: 500px;
    margin: 0 auto;
}

.nav-container .nav-button:first-child {
    justify-self: end;
}

.nav-container .nav-button:last-child {
    justify-self: start;
}

#puzzle-title {
    color: #2563eb;
    font-size: 1.1em;
    margin: 0;
    text-align: center;
    justify-self: center;
}

.nav-button {
    background: #3b82f6;
    color: white;
    border: 2px solid #2563eb;
    border-radius: 6px;
    padding: 6px 12px;
    font-size: 0.8em;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.2s ease;
    white-space: nowrap;
    visibility: hidden; /* Initially hidden, JavaScript will control visibility */
}

.nav-button:hover {
    background: #2563eb;
    border-color: #1d4ed8;
    transform: translateY(-1px);
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
}

/* Only apply hover effects to visible buttons */
.nav-button[style*="visibility: hidden"]:hover {
    background: #3b82f6;
    border-color: #2563eb;
    transform: none;
    box-shadow: none;
}

.nav-button:disabled {
    background: #d1d5db;
    color: #9ca3af;
    border-color: #d1d5db;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

@media (max-width: 600px) {
    .nav-container {
        gap: 10px;
        max-width: 100%;
    }
    
    #puzzle-title {
        font-size: 1.0em;
    }
    
    .nav-button {
        padding: 5px 10px;
        font-size: 0.75em;
    }
}