/* ==========================================================================
   小学家庭作业生成器 · 样式表
   A4 (210mm x 297mm) 精确排版，屏幕所见即打印所得
   ========================================================================== */

:root {
  /* 界面 */
  --bg: #eceff5;
  --panel: #ffffff;
  --ink: #1b2430;
  --ink-2: #5c6879;
  --ink-3: #8d99a8;
  --line: #e2e7ef;
  --line-2: #eef1f6;
  --accent: #3b7cf6;
  --accent-d: #2563eb;
  --accent-soft: #eaf1ff;
  --radius: 10px;

  /* 作业纸 */
  --grid-line: #cf6d6d;
  /* 田字格实线 */
  --grid-soft: #e4a8a8;
  /* 田字格虚线 */
  --ink-paper: #1a1a1a;

  --kai: "KaiTi", "STKaiti", "Kaiti SC", "楷体", "AR PL UKai CN", "SimSun", serif;
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
}

body {
  height: 100vh;
  overflow: hidden;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", "Hiragino Sans GB", sans-serif;
  font-size: 14px;
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}

/* ------------------------------ 布局骨架 ------------------------------ */

.app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

.sidebar {
  flex: 0 0 336px;
  width: 336px;
  display: flex;
  flex-direction: column;
  background: var(--panel);
  border-right: 1px solid var(--line);
  overflow: hidden;
}

.stage {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

/* ------------------------------ 侧栏头部 ------------------------------ */

.brand {
  flex: 0 0 auto;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 16px 18px 12px;
}

.brand-logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(140deg, #4f8dff, #2f66e0);
  color: #fff;
  font-family: var(--kai);
  font-size: 21px;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 10px rgba(47, 102, 224, .28);
}

.brand-title {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .3px;
}

.brand-sub {
  font-size: 11.5px;
  color: var(--ink-3);
  margin-top: 2px;
}

/* ------------------------------ 选项卡 ------------------------------ */

.tabs {
  flex: 0 0 auto;
  display: flex;
  gap: 4px;
  margin: 0 14px 10px;
  padding: 4px;
  background: #f2f5fa;
  border-radius: 10px;
}

.tab {
  flex: 1;
  border: 0;
  background: transparent;
  padding: 8px 0;
  border-radius: 7px;
  font-size: 13.5px;
  font-weight: 600;
  color: var(--ink-2);
  cursor: pointer;
  transition: all .15s;
  font-family: inherit;
}

.tab:hover {
  color: var(--ink);
}

.tab.active {
  background: #fff;
  color: var(--accent-d);
  box-shadow: 0 1px 4px rgba(24, 44, 88, .12);
}

/* ------------------------------ 滚动面板 ------------------------------ */

.panel-body {
  flex: 1 1 auto;
  overflow-y: auto;
  overflow-x: hidden;
  padding: 0 18px 18px;
}

.panel-body::-webkit-scrollbar {
  width: 8px;
}

.panel-body::-webkit-scrollbar-thumb {
  background: #d3dae5;
  border-radius: 4px;
}

.panel-body::-webkit-scrollbar-track {
  background: transparent;
}

.field {
  margin-bottom: 15px;
}

.field-label {
  display: block;
  font-size: 12.5px;
  font-weight: 600;
  color: var(--ink-2);
  margin-bottom: 7px;
}

.field-label .hint {
  font-weight: 400;
  color: var(--ink-3);
  margin-left: 4px;
}

.field-tip {
  font-size: 11.5px;
  line-height: 1.6;
  color: var(--ink-3);
  margin-top: 6px;
}

/* 复选框组 / 小胶囊 */

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 6px 11px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 12.5px;
  color: var(--ink-2);
  background: #fbfcfe;
  cursor: pointer;
  user-select: none;
  transition: all .14s;
}

.chip:hover {
  border-color: #c5d3ea;
}

.chip input {
  display: none;
}

.chip:has(input:checked) {
  background: var(--accent-soft);
  border-color: #9dbbf8;
  color: var(--accent-d);
  font-weight: 600;
}

/* 兼容不支持 :has() 的环境，由 JS 补 on 类 */
.chip.on {
  background: var(--accent-soft);
  border-color: #9dbbf8;
  color: var(--accent-d);
  font-weight: 600;
}

[hidden] {
  display: none !important;
}

.chip .dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  border: 1.5px solid #c2cbd9;
  display: inline-block;
}

.chip:has(input:checked) .dot {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1.5px #fff;
}

.chip.on .dot {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: inset 0 0 0 1.5px #fff;
}

/* 分段选择 */

.seg {
  display: flex;
  gap: 5px;
}

.seg button {
  flex: 1;
  padding: 7px 0;
  border: 1px solid var(--line);
  background: #fbfcfe;
  border-radius: 8px;
  font-size: 12.5px;
  color: var(--ink-2);
  cursor: pointer;
  font-family: inherit;
  transition: all .14s;
}

.seg button:hover {
  border-color: #c5d3ea;
}

.seg button.on {
  background: var(--accent-soft);
  border-color: #9dbbf8;
  color: var(--accent-d);
  font-weight: 600;
}

/* 输入控件 */

input[type=number],
input[type=text],
select,
textarea {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 8px;
  font-size: 13px;
  font-family: inherit;
  color: var(--ink);
  background: #fff;
  outline: none;
  transition: border-color .14s, box-shadow .14s;
}

input[type=number]:focus,
input[type=text]:focus,
select:focus,
textarea:focus {
  border-color: #9dbbf8;
  box-shadow: 0 0 0 3px rgba(59, 124, 246, .12);
}

textarea {
  resize: vertical;
  min-height: 76px;
  line-height: 1.9;
  letter-spacing: .5px;
  font-size: 15px;
}

.row-2 {
  display: flex;
  gap: 9px;
  align-items: center;
  margin-top: 8px;
}

.row-2>* {
  flex: 1;
}

.row-2 .suffix {
  flex: 0 0 auto;
  font-size: 12.5px;
  color: var(--ink-3);
}

/* 通用设置折叠块 */

.sub-title {
  display: flex;
  align-items: center;
  gap: 8px;
  margin: 20px 0 12px;
  font-size: 12px;
  font-weight: 700;
  color: var(--ink-3);
  letter-spacing: .8px;
}

.sub-title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--line-2);
}

/* ------------------------------ 底部按钮 ------------------------------ */

.panel-foot {
  flex: 0 0 auto;
  padding: 12px 18px 16px;
  border-top: 1px solid var(--line);
  background: #fff;
  display: flex;
  gap: 9px;
}

.btn {
  border: 1px solid transparent;
  border-radius: 9px;
  padding: 10px 16px;
  font-size: 13.5px;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  transition: all .15s;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  white-space: nowrap;
}

.btn-primary {
  flex: 1;
  background: var(--accent);
  color: #fff;
  box-shadow: 0 2px 8px rgba(59, 124, 246, .3);
}

.btn-primary:hover {
  background: var(--accent-d);
}

.btn-primary:active {
  transform: translateY(1px);
}

.btn-ghost {
  background: #fff;
  border-color: var(--line);
  color: var(--ink-2);
}

.btn-ghost:hover {
  background: #f6f8fc;
  border-color: #c5d3ea;
}

.btn-ghost:disabled {
  opacity: .5;
  cursor: not-allowed;
}

/* ------------------------------ 顶部工具条 ------------------------------ */

.toolbar {
  flex: 0 0 54px;
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 0 18px;
  background: #fff;
  border-bottom: 1px solid var(--line);
}

.toolbar .spacer {
  flex: 1;
}

.page-badge {
  font-size: 12.5px;
  color: var(--ink-2);
  background: #f2f5fa;
  border-radius: 20px;
  padding: 5px 12px;
  display: none;
}

.page-badge.show {
  display: inline-block;
}

.zoom-group {
  display: flex;
  align-items: center;
  gap: 0;
  border: 1px solid var(--line);
  border-radius: 8px;
  overflow: hidden;
}

.zoom-group button {
  border: 0;
  background: #fff;
  padding: 6px 10px;
  font-size: 12.5px;
  color: var(--ink-2);
  cursor: pointer;
  font-family: inherit;
}

.zoom-group button:hover {
  background: #f6f8fc;
}

.zoom-group button+button {
  border-left: 1px solid var(--line);
}

.zoom-group .val {
  font-size: 12px;
  color: var(--ink-3);
  padding: 0 8px;
  min-width: 44px;
  text-align: center;
}

/* ------------------------------ 预览区 ------------------------------ */

.preview {
  flex: 1;
  overflow: auto;
  padding: 26px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 22px;
  background: #e6eaf1;
}

.preview.fit {
  align-items: center;
}

.sheet {
  flex: 0 0 auto;
  width: 210mm;
  height: 297mm;
  background: #fff;
  position: relative;
  overflow: hidden;
  box-shadow: 0 3px 22px rgba(22, 35, 66, .16);
  color: var(--ink-paper);
  font-family: "Times New Roman", "SimSun", "Songti SC", serif;
}

.sheet-foot {
  position: absolute;
  right: 12mm;
  bottom: 6mm;
  font-size: 9pt;
  color: #999;
  font-family: "Microsoft YaHei", sans-serif;
}

/* 空状态 */

.empty {
  margin: auto;
  text-align: center;
  color: #98a3b3;
}

.empty .big {
  font-family: var(--kai);
  font-size: 58px;
  color: #ccd5e2;
  line-height: 1;
  margin-bottom: 14px;
}

.empty p {
  margin: 0;
  font-size: 13px;
}

/* ==========================================================================
   作业纸 · 通用块
   ========================================================================== */

.blk {
  margin-bottom: 6mm;
}

.measure-box {
  position: absolute;
  left: -10000px;
  top: 0;
  visibility: hidden;
  display: flow-root;
}

/* 抬头 */

.hw-head {
  margin-bottom: 5mm;
}

.hw-title {
  text-align: center;
  font-size: 19pt;
  font-weight: 700;
  letter-spacing: 3px;
  font-family: "Microsoft YaHei", "Heiti SC", sans-serif;
  color: #111;
  padding-bottom: 2.5mm;
}

.hw-meta {
  display: flex;
  align-items: baseline;
  gap: 0;
  font-size: 10.5pt;
  font-family: "Microsoft YaHei", sans-serif;
  color: #222;
  border-bottom: 1.2pt solid #333;
  padding-bottom: 1.6mm;
}

.hw-meta .m {
  display: flex;
  align-items: baseline;
  white-space: nowrap;
}

.hw-meta .m.grow {
  flex: 1;
}

.hw-meta .m.grow .fill {
  flex: 1;
}

.hw-meta .label {
  flex: 0 0 auto;
}

.hw-meta .fill {
  display: inline-block;
  border-bottom: 0.9pt solid #333;
  min-width: 14mm;
  height: 1em;
  margin: 0 4mm 0 1mm;
}

.hw-meta .m:last-child .fill {
  margin-right: 0;
}

.hw-note {
  margin-top: 2.4mm;
  font-size: 10pt;
  color: #444;
  font-family: "Microsoft YaHei", sans-serif;
  line-height: 1.5;
}

/* 小节标题 */

.hw-sec {
  font-size: 12pt;
  font-weight: 700;
  font-family: "Microsoft YaHei", sans-serif;
  color: #111;
  margin: 0 0 3mm;
  padding-left: 0;
}

/* ==========================================================================
   数学
   ========================================================================== */

.p-row {
  display: grid;
  gap: 2mm 5mm;
  margin-bottom: 4.6mm;
}

.p-item {
  display: flex;
  align-items: flex-end;
  font-family: "Times New Roman", "SimSun", serif;
  font-size: var(--fs, 15pt);
  line-height: 1.1;
  color: #111;
  white-space: nowrap;
  overflow: hidden;
}

.p-item .expr {
  flex: 0 0 auto;
}

/*
 * 数字槽 + 运算符 + 等号：宽度写死。
 * 个位数与两位数占同样宽，「=」和答题线因此逐题对齐。
 * --nw 由 JS 按本批题目的最大位数注入。
 */
.p-item .expr i {
  display: inline-block;
  box-sizing: content-box;
  font-style: normal;
  font-variant-numeric: tabular-nums;
  vertical-align: baseline;
}

/*
 * 左边的数字贴右、右边的数字贴左 —— 两个数字各自朝运算符靠拢，
 * 「+ − × ÷」就正好落在两数正中间，且与数字位数无关。
 * 槽宽仍按本批最大位数固定，所以「=」和答题线照样对齐。
 * --nwa / --nwb 分别对应被操作数与操作数的最大位数。
 */
.p-item .expr .a {
  width: calc(var(--nwa, 2) * 1ch);
  text-align: right;
}

.p-item .expr .b {
  width: calc(var(--nwb, 2) * 1ch);
  text-align: left;
}

.p-item .expr .o {
  width: .95em;
  text-align: center;
}

.p-item .expr .e {
  width: .78em;
  text-align: center;
}

/* 答题线：随剩余空间伸缩，地方不够时变短，而不是被裁掉半截 */
.p-item .ans {
  flex: 1 1 11mm;
  min-width: 7mm;
  max-width: 12mm;
  height: 1.05em;
  margin-left: 1.2mm;
  border-bottom: 1pt solid #333;
}

/* 竖式 */

.v-item {
  font-family: "Times New Roman", "SimSun", serif;
  font-size: var(--fs, 15pt);
  color: #111;
  display: flex;
  justify-content: flex-start;
}

.vprob {
  display: inline-block;
  min-width: 26mm;
}

.vprob .vrow {
  display: flex;
  align-items: baseline;
  line-height: 1.35;
}

.vprob .vop {
  flex: 0 0 5.5mm;
  text-align: center;
}

.vprob .vnum {
  flex: 1;
  text-align: right;
  padding-right: 1mm;
  font-variant-numeric: tabular-nums;
}

.vprob .vline {
  border-top: 1.3pt solid #222;
  margin: 1mm 1mm 0 0;
}

.vprob .vspace {
  height: 15mm;
}

/* 答案页 */

.ans-grid {
  display: grid;
  gap: 2.2mm 4mm;
  font-size: 10.5pt;
  font-family: "Times New Roman", "SimSun", serif;
  color: #222;
}

.ans-grid .a {
  white-space: nowrap;
  overflow: hidden;
}

.ans-grid .a .no {
  display: inline-block;
  min-width: 8mm;
  color: #888;
}

.ans-grid .a .val {
  font-weight: 700;
}

/* ==========================================================================
   语文 · 田字格
   ========================================================================== */

.tian-row {
  display: flex;
  justify-content: center;
  width: 100%;
  margin-bottom: 3.6mm;
}

.tian-cell {
  position: relative;
  width: var(--cell, 18mm);
  height: var(--cell, 18mm);
  flex: 0 0 auto;
  border: 0.9pt solid var(--grid-line);
  background: #fff;
}

.tian-cell+.tian-cell {
  margin-left: -0.9pt;
}

/* 虚线（田字格十字 / 米字格对角） */

.tian-cell .gl {
  position: absolute;
  pointer-events: none;
}

.tian-cell .gl-v {
  left: 50%;
  top: 0;
  bottom: 0;
  border-left: 0.7pt dashed var(--grid-soft);
}

.tian-cell .gl-h {
  top: 50%;
  left: 0;
  right: 0;
  border-top: 0.7pt dashed var(--grid-soft);
}

.tian-cell .gl-d1,
.tian-cell .gl-d2 {
  left: 50%;
  top: 50%;
  width: 141.42%;
  border-top: 0.7pt dashed var(--grid-soft);
  transform-origin: center center;
}

.tian-cell .gl-d1 {
  transform: translate(-50%, -50%) rotate(45deg);
}

.tian-cell .gl-d2 {
  transform: translate(-50%, -50%) rotate(-45deg);
}

/* 格内汉字 */

.tian-cell .ch {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--kai);
  font-size: calc(var(--cell, 18mm) * .68);
  line-height: 1;
  color: #111;
  letter-spacing: 0;
  transform: translateY(-1%);
}

.tian-cell .ch.trace {
  color: var(--trace, #efb2b2);
}

.tian-cell .ch.pinyin {
  font-family: "Times New Roman", serif;
}

/* 格子上方的拼音行（可选） */

.tian-wrap {
  margin-bottom: 3.6mm;
}

/* ==========================================================================
   打印
   ========================================================================== */

@page {
  size: A4 portrait;
  margin: 0;
}

@media print {

  html,
  body {
    height: auto !important;
    overflow: visible !important;
    background: #fff !important;
  }

  .app {
    display: block !important;
    height: auto !important;
    overflow: visible !important;
  }

  .sidebar,
  .toolbar {
    display: none !important;
  }

  .stage {
    display: block !important;
    overflow: visible !important;
    height: auto !important;
  }

  .preview {
    display: block !important;
    overflow: visible !important;
    padding: 0 !important;
    gap: 0 !important;
    background: #fff !important;
    zoom: 1 !important;
  }

  .sheet {
    width: 210mm;
    height: 296.6mm;
    box-shadow: none !important;
    margin: 0 !important;
    break-inside: avoid;
    page-break-inside: avoid;
    break-after: page;
    page-break-after: always;
  }

  .sheet:last-child {
    break-after: auto;
    page-break-after: auto;
  }

  * {
    -webkit-print-color-adjust: exact !important;
    print-color-adjust: exact !important;
  }
}