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

body {
    background: #faf8ef;
    font-family: Arial, "Microsoft YaHei", sans-serif;
    overflow-x: hidden;
}

header {
    display: block;
    margin: 0 auto;
    width: 500px;
    text-align: center;
}

header h1 {
    font-family: Arial;
    font-size: 60px;
    font-weight: bold;
    color: #776e65;
}

header #newgamebutton {
    display: block;
    margin: 20px auto;
    width: 120px;
    padding: 12px 10px;
    background-color: #8f7a66;
    font-family: Arial;
    color: white;
    border-radius: 10px;
    text-decoration: none;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s;
}

header #newgamebutton:hover {
    background-color: #9f8b77;
}

header p {
    font-family: Arial;
    font-size: 25px;
    margin: 20px auto;
    color: #776e65;
}

#grid-container {
    overflow: hidden;
    -webkit-overflow-scrolling: touch;
    width: 500px;
    height: 500px;
    padding: 20px;
    margin: 30px auto;
    background-color: #bbada0;
    border-radius: 10px;
    position: relative;
    box-shadow:
        0 0 8px rgba(187,173,160,0.5),
        0 0 20px rgba(187,173,160,0.3);
}

.grid-cell {
    width: 106px;
    height: 106px;
    border-radius: 6px;
    background-color: #ccc0b3;
    position: absolute;
}

.number-cell {
    overflow: hidden;
    white-space: nowrap;
    border-radius: 6px;
    font-family: Arial;
    font-weight: bold;
    font-size: 50px;
    line-height: 106px;
    text-align: center;
    position: absolute;
}

/* 游戏结束遮罩 */
.game-over-mask {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    z-index: 999;
    justify-content: center;
    align-items: center;
}

.game-over-mask.show {
    display: flex;
}

.game-over-dialog {
    background: #fff;
    border-radius: 16px;
    padding: 40px 50px;
    text-align: center;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.3);
    animation: popIn 0.3s ease-out;
}

@keyframes popIn {
    from { transform: scale(0.7); opacity: 0; }
    to { transform: scale(1); opacity: 1; }
}

.game-over-dialog h2 {
    font-size: 36px;
    color: #776e65;
    margin-bottom: 16px;
}

.game-over-dialog p {
    font-size: 18px;
    color: #999;
    margin-bottom: 8px;
}

.final-score {
    font-size: 60px;
    font-weight: bold;
    color: #f67c5f;
    margin-bottom: 24px;
}

.restart-btn {
    display: inline-block;
    padding: 12px 40px;
    background: #8f7a66;
    color: #fff;
    border-radius: 10px;
    text-decoration: none;
    font-size: 18px;
    cursor: pointer;
    transition: background 0.2s;
}

.restart-btn:hover {
    background: #9f8b77;
}


/* 方向键十字布局 */
.dpad {
    width: 180px;
    margin: 20px auto 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    user-select: none;
    -webkit-user-select: none;
}

.dpad-row {
    display: flex;
    align-items: center;
    gap: 6px;
}

.dpad-center {
    width: 52px;
    height: 52px;
}

.dpad-btn {
    width: 52px;
    height: 52px;
    border: none;
    border-radius: 10px;
    background: #8f7a66;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background 0.15s, transform 0.1s;
    -webkit-tap-highlight-color: transparent;
    outline: none;
}

.dpad-btn:hover {
    background: #9f8b77;
}

.dpad-btn:active {
    background: #6d5c4e;
    transform: scale(0.92);
}

.dpad-btn svg {
    width: 22px;
    height: 22px;
    fill: #f9f6f2;
}


/* ============ 手机端响应式 ============ */

/* 超小屏 (<380px) */
@media (max-width: 379px) {
    .number-cell { font-size: 26px; line-height: 56px; }
    header { width: 280px; }
    header h1 { font-size: 36px; }
    header #newgamebutton { width: 100px; padding: 10px 8px; font-size: 14px; margin: 12px auto; }
    header p { font-size: 18px; margin: 12px auto; }
    .dpad { width: 140px; margin: 14px auto 0; gap: 4px; }
    .dpad-row { gap: 4px; }
    .dpad-btn, .dpad-center { width: 42px; height: 42px; }
    .dpad-btn svg { width: 18px; height: 18px; }
    .back-btn { font-size: 13px; padding: 6px 12px 6px 10px; }
    .game-over-dialog { padding: 30px 35px; }
    .game-over-dialog h2 { font-size: 28px; }
    .final-score { font-size: 44px; }
}

/* 小屏 (380-459px) */
@media (min-width: 380px) and (max-width: 459px) {
    .number-cell { font-size: 30px; line-height: 65px; }
    header { width: 320px; }
    header h1 { font-size: 40px; }
    header #newgamebutton { width: 110px; padding: 10px 8px; font-size: 14px; margin: 14px auto; }
    header p { font-size: 20px; margin: 14px auto; }
    .dpad { width: 156px; margin: 16px auto 0; gap: 5px; }
    .dpad-row { gap: 5px; }
    .dpad-btn, .dpad-center { width: 46px; height: 46px; }
    .dpad-btn svg { width: 20px; height: 20px; }
    .back-btn { font-size: 14px; padding: 6px 14px 6px 10px; }
    .game-over-dialog { padding: 32px 40px; }
    .game-over-dialog h2 { font-size: 30px; }
    .final-score { font-size: 48px; }
}

/* 中屏 (460-559px) */
@media (min-width: 460px) and (max-width: 559px) {
    .number-cell { font-size: 38px; line-height: 79px; }
    header { width: 380px; }
    header h1 { font-size: 48px; }
    header #newgamebutton { width: 110px; padding: 11px 8px; font-size: 15px; margin: 16px auto; }
    header p { font-size: 22px; margin: 16px auto; }
    .dpad { width: 170px; margin: 18px auto 0; gap: 5px; }
    .dpad-row { gap: 5px; }
    .dpad-btn, .dpad-center { width: 50px; height: 50px; }
    .dpad-btn svg { width: 21px; height: 21px; }
    .back-btn { font-size: 14px; padding: 7px 14px 6px 10px; }
    .game-over-dialog { padding: 36px 44px; }
    .game-over-dialog h2 { font-size: 32px; }
    .final-score { font-size: 54px; }
}