* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: #f5f7fa;
    color: #333;
    line-height: 1.4;
    transition: background-color 0.3s, color 0.3s;
    overflow: hidden;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

body.dark {
    background-color: #1a1a2e;
    color: #e0e0e0;
}

.a {
    background: #0080ff;
    color: white;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    flex-shrink: 0;
}

.dark .a {
    background: #0060c0;
}

.b {
    max-width: 1200px;
    margin: 0 auto;
    padding: 12px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.e {
    font-size: 24px;
    font-weight: 700;
    letter-spacing: 1px;
}

.g {
    display: flex;
    align-items: center;
    gap: 15px;
}

#h {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s;
}

#h:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.game-container {
    width: 100%;
    max-width: 550px;
    margin: 0 auto;
    padding: 10px 20px;
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    overflow: visible;
}

.score-bar {
    background: white;
    border-radius: 20px;
    padding: 12px 16px;
    margin-bottom: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 10px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.dark .score-bar {
    background: #2d3047;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.score-box {
    display: flex;
    flex-direction: column;
    align-items: center;
    background: #f0f7ff;
    border-radius: 16px;
    padding: 6px 12px;
    min-width: 70px;
}

.dark .score-box {
    background: #2a3a5a;
}

.score-label {
    font-size: 11px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #6c7a89;
    font-weight: 600;
}

.dark .score-label {
    color: #bbccff;
}

.score-value {
    font-size: 24px;
    font-weight: 800;
    color: #0088ff;
    line-height: 1.2;
}

.dark .score-value {
    color: #6cb2ff;
}

.new-game-btn {
    background: #0088ff;
    border: none;
    color: white;
    font-size: 14px;
    font-weight: bold;
    padding: 6px 14px;
    border-radius: 40px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 6px;
    box-shadow: 0 2px 6px rgba(0, 136, 255, 0.3);
}

.new-game-btn:hover {
    background: #0066cc;
    transform: scale(0.97);
}

.w {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    background-color: #eef2f8;
    border-radius: 24px;
    padding: 16px;
    margin-bottom: 10px;
    touch-action: none;
    width: 100%;
    aspect-ratio: 1 / 1;
}

.dark .w {
    background: #252a3c;
}

.status-area {
    text-align: center;
    margin-top: 6px;
}

.status-msg {
    font-size: 14px;
    background: #eef3fc;
    border-radius: 30px;
    padding: 4px 14px;
    font-weight: 500;
    display: inline-block;
}

.dark .status-msg {
    background: #2d3b4f;
    color: #c0d0e8;
}

.control-hint {
    font-size: 12px;
    margin-top: 10px;
    color: #6c86a3;
    display: flex;
    justify-content: center;
    gap: 14px;
    flex-wrap: wrap;
}

.dark .control-hint {
    color: #8ea0bc;
}


/* 原网页风格 footer */

.footer {
    max-width: 1200px;
    margin: 10px auto 20px;
    padding: 20px;
    text-align: center;
    color: #666;
    border-top: 1px solid #eaeaea;
    flex-shrink: 0;
}

.dark .footer {
    color: #aaa;
    border-top: 1px solid #3a3d5c;
}

.notice-content {
    font-size: 16px;
    line-height: 1.8;
}

.notice-content p {
    margin-bottom: 15px;
}

.notice-content #personal-statement {
    font-style: italic;
    color: #666;
    font-size: 18px;
}

.dark .notice-content #personal-statement {
    color: #aaa;
}

.notice-content #update-time {
    font-size: 14px;
    color: #888;
    margin-left: 20px;
}

.dark .notice-content #update-time {
    color: #999;
}

@media (max-width: 560px) {
    .w {
        gap: 8px;
        padding: 12px;
    }
    .score-value {
        font-size: 22px;
    }
    .new-game-btn {
        padding: 5px 12px;
        font-size: 13px;
    }
    .score-box {
        min-width: 60px;
        padding: 5px 10px;
    }
    .e {
        font-size: 22px;
    }
    .b {
        padding: 10px 16px;
    }
    .notice-content #personal-statement {
        font-size: 14px;
    }
    .notice-content {
        font-size: 12px;
    }
}

@media (max-width: 430px) {
    .w {
        gap: 6px;
        padding: 10px;
    }
    .score-value {
        font-size: 20px;
    }
}

.w>div {
    aspect-ratio: 1 / 1;
    background-color: #cddbe9;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.8rem;
    font-weight: 800;
    color: #2d3e50;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.08);
}

.dark .w>div {
    background-color: #3a405b;
    color: #f0f3fc;
}

@media (max-width: 500px) {
    .w>div {
        font-size: 1.4rem;
    }
}

@media (max-width: 400px) {
    .w>div {
        font-size: 1.2rem;
    }
}

.w>div[data-v="2"] {
    background-color: #ede0c8;
    color: #776e65;
}

.w>div[data-v="4"] {
    background-color: #f2b179;
    color: #f9f6f2;
}

.w>div[data-v="8"] {
    background-color: #f59563;
    color: #f9f6f2;
}

.w>div[data-v="16"] {
    background-color: #f67c5f;
    color: #f9f6f2;
}

.w>div[data-v="32"] {
    background-color: #f65e3b;
    color: #f9f6f2;
}

.w>div[data-v="64"] {
    background-color: #ed4b2e;
    color: #f9f6f2;
}

.w>div[data-v="128"] {
    background-color: #edcf72;
    color: #776e65;
}

.w>div[data-v="256"] {
    background-color: #edcc61;
    color: #776e65;
}

.w>div[data-v="512"] {
    background-color: #edc850;
    color: #f9f6f2;
}

.w>div[data-v="1024"] {
    background-color: #edc53f;
    color: #f9f6f2;
}

.w>div[data-v="2048"] {
    background-color: #edc22e;
    color: #f9f6f2;
    box-shadow: 0 0 12px rgba(237, 194, 46, 0.6);
}

.w>div[data-v="4096"] {
    background-color: #3c3a32;
    color: #f9f6f2;
}

.dark .w>div[data-v="2"] {
    background-color: #d6cdb2;
    color: #2c2b26;
}

.dark .w>div[data-v="4"] {
    background-color: #e09d5e;
    color: white;
}

.dark .w>div[data-v="128"] {
    background-color: #e6c384;
    color: #2c2b26;
}

.dark .w>div[data-v="256"] {
    background-color: #e6bd6b;
    color: #2c2b26;
}

.footer a,
.footer a:visited {
    text-decoration: none;
    color: #0080FF;
}

.dark .footer a,
.dark .footer a:visited {
    color: #0080FF;
    text-decoration: none;
}

.footer a:hover,
.dark .footer a:hover {
    color: #3399ff;
}