@import url('https://fonts.googleapis.com/css2?family=Roboto:wght@400;500;700&display=swap');

:root {
    --bg-color: #f0f2f5;
    --card-color: #ffffff;
    --text-color: #333;
    --primary-color: #007bff;
    --primary-hover: #0056b3;
    --border-color: #ddd;
    --progress-bar-color: #28a745;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --kbd-bg-color: #e9ecef;
    --kbd-text-color: #495057;
}

[data-theme="dark"] {
    --bg-color: #1a1a2e;
    --card-color: #16213e;
    --text-color: #e0e0e0;
    --primary-color: #0d8eff;
    --primary-hover: #3a9efd;
    --border-color: #4f5b82;
    --progress-bar-color: #30c554;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --kbd-bg-color: #4f5b82;
    --kbd-text-color: #f0f0f0;
}

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

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: background-color 0.3s, color 0.3s;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    padding: 1rem;
    background-image: url('https://www.transparenttextures.com/patterns/clean-gray-paper.png');
    background-attachment: fixed;
}

.container {
    width: 100%;
    max-width: 800px;
    background-color: var(--card-color);
    border-radius: 16px;
    box-shadow: 0 8px 32px var(--shadow-color);
    padding: 2rem;
    border: 1px solid var(--border-color);
    transition: background-color 0.3s, border-color 0.3s;
    backdrop-filter: blur(5px);
}

header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

h1 {
    font-size: 1.75rem;
    color: var(--primary-color);
}

.theme-switcher { 
    display: flex; 
    align-items: center; 
    gap: 0.5rem; 
}

.theme-switcher .material-symbols-outlined { 
    font-size: 1.25rem; 
}

.switch { 
    position: relative; 
    display: inline-block; 
    width: 44px; 
    height: 24px; 
}

.switch input { 
    opacity: 0; 
    width: 0; 
    height: 0; 
}

.slider { 
    position: absolute; 
    cursor: pointer; 
    top: 0; 
    left: 0; 
    right: 0; 
    bottom: 0; 
    background-color: #ccc; 
    transition: .4s; 
    border-radius: 24px; 
}

.slider:before { 
    position: absolute; 
    content: ""; 
    height: 18px; 
    width: 18px; 
    left: 3px; 
    bottom: 3px; 
    background-color: white; 
    transition: .4s; 
    border-radius: 50%; 
}

input:checked + .slider { 
    background-color: var(--primary-color); 
}

input:checked + .slider:before { 
    transform: translateX(20px); 
}

.counter-display { 
    text-align: center; 
    margin-bottom: 2rem; 
}

#total-count-display { 
    font-size: 4rem; 
    font-weight: 700; 
    line-height: 1; 
}

.progress-bar-container { 
    width: 100%; 
    background-color: var(--border-color); 
    border-radius: 8px; 
    height: 16px; 
    margin-top: 0.5rem; 
    overflow: hidden; 
}

#progress-bar { 
    width: 0%; 
    height: 100%; 
    background-color: var(--progress-bar-color); 
    border-radius: 8px; 
    transition: width 0.2s ease-in-out; 
}

#completion-message { 
    margin-top: 0.5rem; 
    font-weight: 500; 
    color: var(--primary-color); 
    min-height: 24px;
}

.cell-grid { 
    display: grid; 
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); 
    gap: 1rem; 
    margin-bottom: 2rem; 
}

.cell-button {
    background-color: var(--bg-color);
    border: 2px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem;
    text-align: center;
    cursor: pointer;
    transition: transform 0.1s, border-color 0.2s, background-color 0.2s;
    user-select: none;
    position: relative;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
}

.cell-button:hover { 
    border-color: var(--primary-color); 
    transform: translateY(-3px); 
}

.cell-button.active { 
    transform: scale(0.95); 
    background-color: var(--primary-color); 
    color: white; 
}

.cell-name { 
    font-weight: 500; 
    font-size: 1rem; 
}

kbd { 
    background-color: var(--kbd-bg-color); 
    color: var(--kbd-text-color); 
    border-radius: 4px; 
    padding: 2px 6px; 
    font-size: 0.8rem; 
    font-family: monospace; 
    position: absolute; 
    top: 8px; 
    left: 8px; 
}

.cell-count { 
    display: block; 
    font-size: 1.5rem; 
    font-weight: 700; 
    margin-top: 0.5rem; 
}

.controls { 
    display: flex; 
    justify-content: center; 
    gap: 1rem; 
}

button { 
    padding: 0.75rem 1.5rem; 
    font-size: 1rem; 
    font-weight: 500; 
    border-radius: 8px; 
    border: none; 
    cursor: pointer; 
    transition: background-color 0.2s, transform 0.1s; 
}

#reset-button { 
    background-color: #dc3545; 
    color: white; 
}

#reset-button:hover { 
    background-color: #c82333; 
}

#copy-button { 
    background-color: var(--primary-color); 
    color: white; 
}

#copy-button:hover { 
    background-color: var(--primary-hover); 
}

button:active { 
    transform: scale(0.97); 
}

.cell-button img {
    width: 48px;
    height: 48px;
    margin-bottom: 0.5rem;
    object-fit: contain;
    filter: drop-shadow(0 2px 2px rgba(0,0,0,0.2));
}

.cell-button.active img {
    filter: brightness(0) invert(1);
}

footer a {
    color: inherit;
    text-decoration: none;
    font-weight: 600;
    padding: 2px 4px;
    border-radius: 4px;
    transition: background-color 0.3s, color 0.3s;
}

footer a:hover {
    color: var(--card-color);
    background-color: var(--primary-color);
    text-decoration: none;
}

#modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.7);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 1000;
    backdrop-filter: blur(5px);
}

#correction-modal {
    background-color: var(--card-color);
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 5px 25px rgba(0,0,0,0.2);
    width: 90%;
    max-width: 450px;
    text-align: center;
    border: 1px solid var(--border-color);
}

#correction-modal h2 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

#correction-modal p {
    margin-bottom: 1.5rem;
    line-height: 1.5;
}

.input-group {
    position: relative;
    margin-bottom: 1.5rem;
}

.input-group input {
    width: 100%;
    padding: 1rem;
    font-size: 1.2rem;
    border-radius: 8px;
    border: 2px solid var(--border-color);
    background-color: var(--bg-color);
    color: var(--text-color);
    text-align: center;
}

.input-group label {
    position: absolute;
    top: -10px;
    left: 15px;
    background-color: var(--card-color);
    padding: 0 5px;
    font-size: 0.9rem;
    color: var(--text-color);
}

.modal-buttons {
    display: flex;
    justify-content: space-between;
    gap: 1rem;
}

.modal-buttons button {
    flex-grow: 1;
}

#cancel-button {
    background-color: transparent;
    border: 2px solid var(--border-color);
    color: var(--text-color);
}

#calculate-button {
    background-color: var(--primary-color);
    color: white;
}

#corrected-result-display, #calculation-details {
    margin-top: 1.5rem;
    font-size: 1.1rem;
    font-weight: 500;
    min-height: 30px;
    background-color: var(--bg-color);
    padding: 1rem;
    border-radius: 8px;
}

#calculation-details {
    font-family: monospace;
    font-size: 1rem;
    color: var(--primary-hover);
    padding-top: 0;
    padding-bottom: 0;
}

.hidden {
    display: none !important;
}