/* ── 主题变量（与主站 globals.css 保持同步） ── */
:root {
  --radius: 0.625rem;
  --background: oklch(1 0 0);
  --foreground: oklch(0.145 0 0);
  --card: oklch(1 0 0);
  --card-foreground: oklch(0.145 0 0);
  --primary: oklch(20.463% 0.00002 271.152);
  --primary-foreground: oklch(0.985 0 0);
  --secondary: oklch(0.90 0 150);
  --secondary-foreground: oklch(0.205 0 0);
  --muted: oklch(0.95 0 271);
  --muted-foreground: oklch(0.556 0 0);
  --accent: oklch(0.87 0 271);
  --accent-foreground: oklch(0.205 0 0);
  --destructive: oklch(0.577 0.245 27.325);
  --destructive-foreground: oklch(0.985 0 0);
  --border: oklch(0.922 0 0);
  --input: oklch(0.922 0 0);
  --ring: oklch(0.708 0 0);
  /* 数独专用 */
  --cell-bg: oklch(1 0 0);
  --cell-bg-initial: oklch(0.97 0 0);
  --cell-selected: oklch(0.88 0.04 250);
  --cell-highlight: oklch(0.94 0.01 250);
  --cell-error: oklch(0.92 0.06 20);
  --cell-user: oklch(0.40 0.12 250);
  --border-soft: oklch(0.85 0 0);
  --border-strong: oklch(0.60 0 0);
}

.dark {
  --background: oklch(0.145 0 0);
  --foreground: oklch(0.985 0 0);
  --card: oklch(0.205 0 0);
  --card-foreground: oklch(0.985 0 0);
  --primary: oklch(0.922 0 0);
  --primary-foreground: oklch(0.205 0 0);
  --secondary: oklch(0.269 0 0);
  --secondary-foreground: oklch(0.985 0 0);
  --muted: oklch(0.269 0 0);
  --muted-foreground: oklch(0.708 0 0);
  --accent: oklch(0.269 0 0);
  --accent-foreground: oklch(0.985 0 0);
  --destructive: oklch(0.704 0.191 22.216);
  --destructive-foreground: oklch(0.985 0 0);
  --border: oklch(1 0 0 / 10%);
  --input: oklch(1 0 0 / 15%);
  --ring: oklch(0.556 0 0);
  --cell-bg: oklch(0.205 0 0);
  --cell-bg-initial: oklch(0.18 0 0);
  --cell-selected: oklch(0.32 0.06 250);
  --cell-highlight: oklch(0.25 0.02 250);
  --cell-error: oklch(0.28 0.08 20);
  --cell-user: oklch(0.72 0.10 250);
  --border-soft: oklch(1 0 0 / 12%);
  --border-strong: oklch(1 0 0 / 35%);
}

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

body {
  font-family: 'HarmonyOS Sans SC', ui-sans-serif, system-ui, sans-serif;
  display: flex;
  flex-direction: column;
  align-items: center;
  background-color: transparent;
  color: var(--foreground);
  transition: color 0.2s ease;
}

/* --- 导航栏 --- */
.navbar {}
.nav-brand {}
.nav-brand h1 {}
.nav-functional-buttons {}

#timer-display {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 22px;
    font-weight: bold;
    color: var(--muted-foreground);
    flex-shrink: 0;
}
#timer { display: inline-block; line-height: 1; }

.icon-button {
    background: none;
    border: none;
    color: var(--muted-foreground);
    font-size: 22px;
    cursor: pointer;
    padding: 0;
    border-radius: 0;
    width: 32px;
    height: 22px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    transition: color 0.2s ease, transform 0.1s ease;
    flex-shrink: 0;
}
.icon-button:hover { color: var(--foreground); }
.icon-button:active { transform: scale(0.95); }

/* --- 前置页面 --- */
.start-page {
    position: fixed;
    top: 0; left: 0; width: 100%; height: 100%;
    background-color: transparent;
    display: none; justify-content: center; align-items: center;
    z-index: 10;
}
.difficulty-container { text-align: center; color: var(--foreground); }
.game-title { font-size: 3.5rem; font-weight: 700; margin-bottom: 2rem; color: var(--foreground); text-shadow: 0 0 20px color-mix(in oklch, var(--foreground) 20%, transparent); }
.difficulty-buttons { display: flex; flex-direction: column; gap: 1rem; align-items: center; }
.difficulty-btn {
    padding: 1rem 2rem; font-size: 1.25rem; font-weight: 500;
    background-color: var(--card); color: var(--card-foreground);
    border: 1px solid var(--border); border-radius: var(--radius);
    cursor: pointer; transition: all 0.2s ease; min-width: 300px;
    box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
}
.difficulty-btn:hover { background-color: var(--accent); color: var(--accent-foreground); transform: translateY(-2px); box-shadow: 0 4px 6px -1px rgb(0 0 0 / 0.1); }
.difficulty-btn:active { transform: translateY(0); box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05); }
.nightmare-mode { background-color: color-mix(in oklch, var(--destructive) 10%, transparent); border-color: color-mix(in oklch, var(--destructive) 20%, transparent); color: var(--destructive); }
.nightmare-mode:hover { background-color: color-mix(in oklch, var(--destructive) 20%, transparent); border-color: color-mix(in oklch, var(--destructive) 30%, transparent); color: var(--destructive); }

.game-page { width: 100%; justify-content: center; }

/* 游戏内控制按钮（返回） */
.game-controls { position: fixed; top: 16px; left: 16px; z-index: 100; }
.control-btn {
    padding: 8px 16px; font-size: 0.875rem; font-weight: 500;
    background-color: var(--secondary); color: var(--secondary-foreground);
    border: 1px solid var(--border); border-radius: var(--radius);
    cursor: pointer; transition: all 0.2s ease;
    box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
}
.control-btn:hover { background-color: color-mix(in oklch, var(--secondary) 80%, transparent); }
.primary-btn {
    background-color: var(--primary);
    color: var(--primary-foreground);
    border-color: transparent;
}
.primary-btn:hover { background-color: color-mix(in oklch, var(--primary) 90%, transparent); }

/* --- 主要游戏区域 --- */
.game-area {
    display: flex;
    flex-direction: column;
    align-items: center;
    margin: 7dvh auto 0;
    width: 100%;
    max-width: 900px;
    padding: 0;
}

.sudoku-and-right-panel-wrapper {
    display: flex;
    flex-direction: row;
    gap: 25px;
    justify-content: center;
    align-items: flex-start;
    width: 100%;
    max-width: 800px;
    margin: 0 auto;
}

#sudoku-container {
    display: grid;
    grid-template-columns: repeat(9, 50px);
    grid-template-rows: repeat(9, 50px);
    border: 3px solid var(--border-strong);
    background-color: var(--card);
    box-shadow: 0 4px 12px rgb(0 0 0 / 0.08);
    border-radius: var(--radius);
    overflow: hidden;
    flex-shrink: 0;
}

.cell {
    width: 50px;
    height: 50px;
    border: 1px solid var(--border-soft);
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 30px;
    font-weight: 600;
    box-sizing: border-box;
    transition: background-color 0.1s ease;
    -webkit-user-select: none;
    user-select: none;
    position: relative;
    overflow: hidden;
    min-width: 0;
    min-height: 0;
    background-color: var(--cell-bg);
    color: var(--foreground);
}

/* 笔记模式 */
.cell.note-mode-display .pencil-notes {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    font-size: 10px;
    font-weight: normal;
    color: var(--muted-foreground);
    width: 100%;
    height: 100%;
    align-items: center;
    justify-items: center;
    line-height: 1;
    padding: 2px;
    box-sizing: border-box;
}
.cell.note-mode-display .pencil-notes span {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
    line-height: 1;
}

/* 3x3 宫格粗边框 */
.cell:nth-child(3n)                              { border-right:  2px solid var(--border-strong); }
.cell:nth-child(9n)                              { border-right:  3px solid var(--border-strong); }
.cell:nth-child(n+1):nth-child(-n+9)             { border-top:    3px solid var(--border-strong); }
.cell:nth-child(n+19):nth-child(-n+27),
.cell:nth-child(n+46):nth-child(-n+54)           { border-bottom: 2px solid var(--border-strong); }
.cell:nth-child(n+73):nth-child(-n+81)           { border-bottom: 3px solid var(--border-strong); }
.cell                                            { border-left:   1px solid var(--border-soft); }
.cell:nth-child(9n+1)                            { border-left:   3px solid var(--border-strong); }

.cell.initial {
    color: var(--foreground);
    background-color: var(--cell-bg-initial);
    cursor: default;
}
.cell.user-input {
    color: var(--cell-user);
    cursor: pointer;
}
.cell.selected    { background-color: var(--cell-selected); }
.cell.highlight   { background-color: var(--cell-highlight); }
.cell.error       { background-color: var(--cell-error); color: var(--destructive); }
.right-panel {
    display: flex;
    flex-direction: column;
    gap: 12px;
    width: 220px;
    align-items: stretch;
    flex-shrink: 0;
    padding: 0;
}

/* 顶部信息行：错误、计时器、暂停 */
.top-info-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    padding: 8px 10px;
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.06);
    font-weight: bold;
    color: var(--muted-foreground);
}

#error-count {
    font-size: 16px;
    color: var(--destructive);
}


/* 顶部操作按钮行：撤销、笔记、橡皮擦、提示 */
.top-action-row {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 5px;
    width: 100%;
}

.icon-action-btn { /* 图标操作按钮 */
    background-color: var(--secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 7px 0;
    font-size: 20px;
    color: var(--secondary-foreground);
    cursor: pointer;
    box-shadow: 0 1px 2px rgb(0 0 0 / 0.05);
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.1s ease;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    flex: 1;
    min-width: 0;
}

.icon-action-btn:hover {
    background-color: var(--accent);
    color: var(--accent-foreground);
}
.icon-action-btn:active { /* 按钮点击呼吸感 */
    transform: scale(0.95);
    background-color: color-mix(in oklch, var(--accent) 80%, transparent);
}
.icon-action-btn.active { /* 笔记模式激活状态 */
    background-color: var(--primary);
    color: var(--primary-foreground);
    box-shadow: 0 2px 6px rgb(0 0 0 / 0.15);
}

.icon-action-btn .icon-glyph {
    font-size: 1.1rem;
    line-height: 1;
}
.icon-action-btn .icon-label {
    font-size: 12px;
    /* margin-top: 6px; */
    color: inherit;
}



/* --- 数字输入面板 (九宫格) --- */
#number-input-panel {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 8px;
    width: 100%;
    background-color: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: 0 1px 3px rgb(0 0 0 / 0.06);
    padding: 10px;
}
.num-btn {
    padding: 0;
    font-size: 22px;
    border: 1px solid var(--border);
    border-radius: calc(var(--radius) - 2px);
    background-color: var(--secondary);
    color: var(--secondary-foreground);
    cursor: pointer;
    transition: background-color 0.2s ease, transform 0.1s ease;
    font-weight: bold;
    box-shadow: 0 1px 2px rgb(0 0 0 / 0.05);
    aspect-ratio: 1 / 1;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
    width: 100%;
}

.num-btn:hover {
    background-color: var(--accent);
    color: var(--accent-foreground);
}
.num-btn:active { /* 按钮点击呼吸感 */
    transform: scale(0.95);
    background-color: color-mix(in oklch, var(--accent) 80%, transparent);
}

.num-btn .remaining-badge {
    position: absolute;
    top: 4px;
    right: 6px;
    font-size: 11px;
    color: var(--muted-foreground);
    pointer-events: none;
}

.num-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    box-shadow: none;
}


/* 底部"新游戏"按钮 */
.new-game-bottom-btn {
    width: 100%; /* 撑满右侧面板宽度 */
    padding: 12px;
    font-size: 1rem;
    margin-top: 5px;
}

/* 消息提示区 (独立于右侧面板) */
#message {
    margin-top: 20px;
    font-size: 20px;
    font-weight: bold;
    color: var(--foreground);
    min-height: 28px;
    text-align: center;
    width: 100%;
    max-width: 600px;
}
/* --- 响应式调整 --- */
@media (max-width: 900px) { /* 当屏幕宽度小于 900px 时，数独和右侧面板垂直堆叠 */
    .sudoku-and-right-panel-wrapper {
        flex-direction: column;
        align-items: center;
        gap: 30px;
        max-width: 650px; /* 与棋盘视觉宽度一致 */
    }

    .right-panel { width: 100%; max-width: 450px; padding: 0 10px; margin: 0 auto; }

    /* 移动端数字输入面板和操作按钮 */
    #number-input-panel {
        padding: 15px; /* 调整内边距 */
        gap: 10px; /* 调整间距 */
    }

    .num-btn {
        font-size: 22px; /* 缩小字体 */
        padding: 12px; /* 缩小内边距 */
    }
    
    .top-info-row, .top-action-row, .new-game-bottom-btn { max-width: 450px; width: 100%; }
    /* 当顶部信息行被移动到棋盘上方（成为 wrapper 的直接子元素）时，给予左右外间距 */
    .sudoku-and-right-panel-wrapper > .top-info-row { width: calc(100% - 30px); margin: 0 auto; }
}


@media (max-width: 768px) {
    body { padding-top: 0; }
    .navbar {
        flex-direction: column;
        padding: 10px 15px;
        gap: 10px;
        align-items: flex-start;
    }
    .nav-brand {
        margin-right: 0;
        width: 100%;
        text-align: center;
    }

    /* 移动端，所有功能按钮组垂直堆叠并居中 */
    .nav-functional-buttons {
        flex-direction: column; /* 垂直堆叠 */
        align-items: center; /* 居中 */
        margin-left: 0; /* 取消 auto margin */
        padding-right: 0; /* 取消右侧留白 */
        width: 100%;
        gap: 10px; /* 增加垂直间距 */
    }
    
    /* 调整移动端下拉菜单宽度（计时器不再占满） */
    .dropdown-container {
        width: 100%;
        justify-content: center; /* 内部元素居中 */
    }
    /* 确保右侧面板的顶部信息行中，计时器不撑满 */
    .top-info-row #timer-display {
        width: auto;
        justify-content: flex-end;
        flex-shrink: 0;
    }
    .dropdown-toggle {
        width: 100%;
        justify-content: center;
        font-size: 15px;
        padding: 8px 12px;
    }
    .dropdown-menu {
        width: 90%; /* 宽度跟随父级 */
        left: 50%;
        transform: translateX(-50%); /* 居中 */
    }
    .dropdown-menu button {
        font-size: 15px;
    }
    #timer-display {
        font-size: 18px;
        margin-left: 0; /* 取消左边距 */
    }
    #timer-display .icon-button {
        font-size: 16px;
    }


    #sudoku-container {
        width: calc(100vw - 24px);
        aspect-ratio: 1 / 1;
        grid-template-columns: repeat(9, 1fr);
        grid-template-rows: repeat(9, 1fr);
        border-width: 3px;
    }
    .cell {
        width: auto;
        height: auto;
        aspect-ratio: 1 / 1;
        font-size: 24px;
        border-width: 1px;
    }
    /* 媒体查询中的粗边框（统一暗色） */
    .cell:nth-child(3n) { border-right: 2px solid var(--border-strong); }
    .cell:nth-child(9n) { border-right: 3px solid var(--border-strong); }
    .cell:nth-child(n + 1):nth-child(-n + 9) { border-top: 3px solid var(--border-strong); }
    .cell:nth-child(n + 19):nth-child(-n + 27),
    .cell:nth-child(n + 46):nth-child(-n + 54) { border-bottom: 2px solid var(--border-strong); }
    .cell:nth-child(n + 73):nth-child(-n + 81) { border-bottom: 3px solid var(--border-strong); }
    .cell:nth-child(9n+1) { border-left: 3px solid var(--border-strong); }

    .right-panel { width: calc(100vw - 24px); max-width: calc(100vw - 24px); margin: 0 auto; padding: 0 10px; }
    .top-info-row, .top-action-row, .new-game-bottom-btn { width: 100%; max-width: 100%; }
    .top-info-row { width: 100%; margin: 0; }
    .sudoku-and-right-panel-wrapper > .top-info-row { width: calc(100% - 40px); margin: 0 auto; }
    #number-input-panel { display: grid; grid-template-columns: repeat(9, 1fr); gap: 5px; padding: 8px; }
    .num-btn { aspect-ratio: initial; padding: 8px; font-size: 18px; min-height: 44px; }
}

@media (max-width: 480px) {
    body { padding-top: 0; }
    .game-area { padding: 0; max-width: 100vw; }
    .icon-button {
        font-size: 20px;
        padding: 6px;
    }
    #sudoku-container { width: calc(100vw - 20px); aspect-ratio: 1 / 1; grid-template-columns: repeat(9, 1fr); grid-template-rows: repeat(9, 1fr); }
    .cell { width: auto; height: auto; aspect-ratio: 1 / 1; font-size: 22px; }
    #number-input-panel { display: grid; grid-template-columns: repeat(9, 1fr); gap: 4px; padding: 6px; }
    .num-btn { aspect-ratio: initial; padding: 6px; font-size: 16px; min-height: 44px; }
    .right-panel { width: calc(100vw - 20px); max-width: calc(100vw - 20px); margin: 0 auto; padding: 0 8px; }
    .top-info-row, .top-action-row, .new-game-bottom-btn { width: 100%; max-width: 100%; }
    .top-info-row { width: calc(100% - 16px); margin: 0 auto; }
}

@media (hover: none) {
    .icon-button:hover { color: var(--muted-foreground); }
    .difficulty-btn:hover { background-color: var(--accent); color: var(--accent-foreground); }
    .icon-action-btn:hover { background-color: var(--secondary); color: var(--secondary-foreground); }
    .num-btn:hover { background-color: var(--secondary); color: var(--secondary-foreground); }
}