:root {
    --background-color: #121212;
    --surface-color: #1e1e1e;
    --primary-color: #bb86fc;
    --primary-variant-color: #3700b3;
    --secondary-color: #03dac6;
    --on-background-color: #e0e0e0;
    --on-surface-color: #ffffff;
    --error-color: #cf6679;
    --border-color: #333;
    --grid-size: min(90vw, 540px);
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--background-color);
    color: var(--on-background-color);
    display: flex;
    flex-direction: column;
    min-height: 100vh;
    align-items: center;
    padding: 1rem;
}

.header {
    width: 100%;
    max-width: var(--grid-size);
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
}

.header__brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary-color);
}

.button {
    background-color: var(--surface-color);
    color: var(--primary-color);
    border: 1px solid var(--primary-color);
    padding: 0.5rem 1rem;
    border-radius: 4px;
    cursor: pointer;
    font-size: 0.9rem;
    transition: background-color 0.2s, color 0.2s;
}

.button:hover {
    background-color: var(--primary-variant-color);
    color: var(--on-surface-color);
}

.button--active {
    background-color: var(--primary-color);
    color: var(--surface-color);
}

.main {
    width: 100%;
    max-width: var(--grid-size);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.game-status {
    width: 100%;
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
    color: var(--secondary-color);
}

.sudoku-grid {
    width: var(--grid-size);
    height: var(--grid-size);
    display: grid;
    grid-template-columns: repeat(9, 1fr);
    grid-template-rows: repeat(9, 1fr);
    border: 3px solid var(--primary-color);
    border-radius: 5px;
    background-color: var(--surface-color);
}

.sudoku-grid__cell {
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: clamp(1rem, 5vw, 2rem);
    border: 1px solid var(--border-color);
    position: relative;
    cursor: pointer;
}

.sudoku-grid__cell:nth-child(3n) {
    border-right-color: var(--primary-color);
}
.sudoku-grid__cell:nth-child(9n) {
    border-right: none;
}
.sudoku-grid__cell:nth-child(n+19):nth-child(-n+27),
.sudoku-grid__cell:nth-child(n+46):nth-child(-n+54) {
    border-bottom-color: var(--primary-color);
}

.sudoku-grid__cell--given {
    color: var(--on-surface-color);
    font-weight: bold;
}

.sudoku-grid__cell--selected {
    background-color: var(--primary-variant-color);
}

.sudoku-grid__cell--highlighted {
    background-color: rgba(187, 134, 252, 0.3);
}

.sudoku-grid__cell--error {
    color: var(--error-color);
}

.sudoku-grid__cell .notes-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    width: 100%;
    height: 100%;
    position: absolute;
    top: 0;
    left: 0;
    font-size: clamp(0.5rem, 1.5vw, 0.8rem);
    color: var(--secondary-color);
}

.notes-grid__note {
    display: flex;
    justify-content: center;
    align-items: center;
}

.controls {
    margin-top: 1rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.controls__numbers {
    display: flex;
    gap: 0.5rem;
}

.btn-num {
    width: 3rem;
    height: 3rem;
    font-size: 1.5rem;
    background-color: var(--surface-color);
    color: var(--on-surface-color);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    cursor: pointer;
}

.controls__actions {
    display: flex;
    gap: 0.5rem;
}

.footer {
    margin-top: 2rem;
    padding: 1rem;
    max-width: var(--grid-size);
    text-align: center;
    color: #aaa;
    font-size: 0.9rem;
}

.footer h1 {
    font-size: 1.2rem;
    color: var(--on-background-color);
    margin-bottom: 0.5rem;
}

.footer h2 {
    font-size: 1rem;
    color: var(--on-background-color);
    margin-top: 1rem;
    margin-bottom: 0.5rem;
}

.footer ul {
    list-style: none;
    padding: 0;
    margin-bottom: 1rem;
}

.footer .copyright {
    font-size: 0.8rem;
    margin-top: 1rem;
}

.footer-nav {
    margin-top: 2rem;
    font-size: 0.9rem;
}

.footer-nav a {
    color: var(--primary-color);
    text-decoration: none;
    padding: 0.5rem;
    transition: color 0.2s;
}

.footer-nav a:hover {
    color: var(--secondary-color);
}

/* 静态页面样式 */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
    background-color: var(--surface-color);
    border-radius: 8px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.container h1 {
    color: var(--primary-color);
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
    text-align: center;
    font-weight: 700;
}

.container section {
    margin: 2.5rem 0;
    padding: 1.5rem;
    background: rgba(187, 134, 252, 0.05);
    border-radius: 6px;
    border-left: 4px solid var(--primary-color);
}

.container section h2 {
    color: var(--secondary-color);
    font-size: 1.5rem;
    margin-bottom: 1rem;
    font-weight: 600;
}

.container p {
    line-height: 1.8;
    margin-bottom: 1.2rem;
    color: var(--on-background-color);
}

.container ul {
    list-style-type: none;
    padding-left: 1.2rem;
    margin: 1rem 0;
}

.container ul li {
    position: relative;
    padding-left: 1.5rem;
    margin-bottom: 0.8rem;
    line-height: 1.6;
}

.container ul li::before {
    content: "•";
    color: var(--primary-color);
    font-size: 1.2em;
    position: absolute;
    left: 0;
    top: -1px;
}

.meta-info {
    text-align: center;
    color: var(--secondary-color);
    font-size: 0.9rem;
    margin-bottom: 2rem;
    font-style: italic;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin: 2rem 0;
}

.contact-method {
    background: var(--surface-color);
    padding: 1.5rem;
    border-radius: 8px;
    text-align: center;
    border: 1px solid rgba(187, 134, 252, 0.2);
    transition: transform 0.2s, border-color 0.2s;
}

.contact-method:hover {
    transform: translateY(-4px);
    border-color: var(--primary-color);
}

.contact-method h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

.contact-method a {
    color: var(--secondary-color);
    text-decoration: none;
    font-size: 1.1rem;
    transition: color 0.2s;
}

.contact-method a:hover {
    color: var(--primary-color);
}

.highlight-box {
    background: linear-gradient(145deg, rgba(187, 134, 252, 0.1), rgba(3, 218, 198, 0.1));
    padding: 2rem;
    border-radius: 8px;
    margin: 2rem 0;
    text-align: center;
}

.highlight-box h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
}

/* 底部导航样式优化 */
.static-footer {
    margin-top: 3rem;
    padding: 1rem;
    border-top: 1px solid rgba(187, 134, 252, 0.2);
    text-align: center;
}

.static-footer a {
    color: var(--primary-color);
    text-decoration: none;
    margin: 0 1rem;
    transition: color 0.2s;
}

.static-footer a:hover {
    color: var(--secondary-color);
}

/* 模态对话框样式 */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal-overlay.is-active {
    display: flex;
}

.modal {
    background-color: var(--surface-color);
    border-radius: 8px;
    padding: var(--spacing-l);
    max-width: 400px;
    width: 90%;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    transform: translateY(-20px);
    opacity: 0;
    transition: transform 0.3s ease, opacity 0.3s ease;
}

.modal-overlay.is-active .modal {
    transform: translateY(0);
    opacity: 1;
}

.modal__content {
    text-align: center;
}

.modal__title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-m);
    color: var(--primary-color);
}

.modal__message {
    margin-bottom: var(--spacing-l);
    line-height: 1.5;
    color: var(--on-background-color);
}

.modal__actions {
    display: flex;
    justify-content: center;
    gap: var(--spacing-m);
}

.modal__button {
    min-width: 100px;
}

.modal__button--cancel {
    background-color: transparent;
    border-color: var(--border-color);
}

.modal__button--confirm {
    background-color: var(--primary-color);
    color: var(--surface-color);
}

/* 胜利弹窗特殊样式 */
.modal__content.victory {
    padding: var(--spacing-xl);
}

.stats-display {
    display: flex;
    justify-content: center;
    gap: var(--spacing-xl);
    margin: var(--spacing-l) 0;
}

.stat-item {
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.9em;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xs);
}

.stat-value {
    display: block;
    font-size: 1.8em;
    font-weight: var(--font-weight-bold);
    color: var(--primary-color);
}

.share-section {
    background-color: rgba(0, 0, 0, 0.2);
    border-radius: var(--spacing-s);
    padding: var(--spacing-m);
    margin: var(--spacing-m) 0;
}

.share-label {
    font-size: 0.9em;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-s);
}

.share-text {
    font-family: monospace;
    background-color: rgba(0, 0, 0, 0.3);
    border-radius: var(--spacing-xs);
    padding: var(--spacing-s);
    margin-bottom: var(--spacing-m);
    color: var(--color-text-primary);
    white-space: pre-wrap;
}

.modal__button--share {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-s);
    margin-bottom: var(--spacing-m);
}

.modal__button--share svg {
    transition: transform 0.2s ease;
}

.modal__button--share:hover svg {
    transform: translateY(-2px);
}