:root {
  /*
   * 全站字級的總開關。
   *
   * 主要使用場景是老師拿著手機在教室裡點，不是坐在電腦前面，
   * 所以基準訂在手機看得清楚的大小（瀏覽器預設值是 16px）。
   * 全站的 font-size 一律寫成 rem，改這一個值就整站一起縮放——
   * 不要在個別元件裡改回 px，那會讓這個開關失效。
   * 最小的說明文字在換算時就設了 12px 的下限（0.75rem），再小老師看不清楚。
   */
  font-size: 18px;

  --bg: #f4f7f5;
  --surface: #ffffff;
  --surface-2: #eef3ef;
  --ink: #1d2b24;
  --ink-soft: #5b6b62;
  --line: #d9e3dc;
  --green: #2f7a5b;
  --green-soft: #e3f2ea;
  --amber: #92540d;
  --amber-soft: #fdf0dc;
  --red: #b23b3b;
  --red-soft: #fbe6e6;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(29, 43, 36, .06), 0 8px 24px rgba(29, 43, 36, .06);
}

* { box-sizing: border-box; }

/* display:flex 會蓋掉 hidden 屬性，這條把它拉回來 */
[hidden] { display: none !important; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "PingFang TC", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
}

h2, h3, h4 { margin: 0; font-weight: 700; }
p { margin: 0; }

/* ---- 頂列 ---- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 0;
  z-index: 20;
  flex-wrap: wrap;
}

.brand { display: flex; align-items: center; gap: 8px; }
.logo { color: var(--green); font-size: 1.25rem; }
.logo-img { flex: 0 0 auto; }
.brand-name { font-weight: 700; font-size: 1.0625rem; letter-spacing: .02em; }

.topbar-controls { display: flex; gap: 8px; }

select {
  font: inherit;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--ink);
  min-height: 44px;
}

/* ---- 分頁 ---- */

.tabs {
  display: flex;
  gap: 4px;
  padding: 8px 16px 0;
  background: var(--surface);
  border-bottom: 1px solid var(--line);
  position: sticky;
  top: 69px;
  z-index: 19;
  overflow: visible;
}

.tab {
  font: inherit;
  font-weight: 600;
  border: none;
  background: none;
  color: var(--ink-soft);
  padding: 10px 14px;
  border-bottom: 3px solid transparent;
  cursor: pointer;
  white-space: nowrap;
  min-height: 44px;
}

.tab.is-active { color: var(--green); border-bottom-color: var(--green); }
.primary-tabs { display: flex; min-width: 0; }

.more-menu { margin-left: auto; position: relative; }
.more-menu > summary { cursor: pointer; list-style: none; min-height: 44px; padding: 10px 14px; color: var(--ink-soft); font-weight: 600; white-space: nowrap; }
.more-menu > summary::-webkit-details-marker { display: none; }
.more-menu > summary::after { content: "⌄"; margin-left: 6px; }
.more-menu[open] > summary { color: var(--green); }
.tab-links {
  position: absolute;
  right: 0;
  top: calc(100% + 6px);
  width: min(430px, calc(100vw - 24px));
  max-height: min(640px, calc(100dvh - 188px));
  overflow-y: auto;
  overscroll-behavior: contain;
  scrollbar-gutter: stable;
  padding: 10px;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: var(--shadow);
  z-index: 30;
}
.tool-group + .tool-group { margin-top: 10px; padding-top: 10px; border-top: 1px solid var(--line); }
.tool-group-title { margin: 0 4px 6px; color: var(--ink-soft); font-size: 0.75rem; letter-spacing: .08em; }
.tool-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
.tool-link {
  min-width: 0;
  min-height: 80px;
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  align-items: center;
  gap: 9px;
  padding: 8px;
  color: var(--ink);
  text-decoration: none;
  background: #fbfdfb;
  border: 1px solid var(--line);
  border-radius: 12px;
}
.tool-link:hover { color: var(--green); background: var(--green-soft); border-color: #a9cdb9; }
.tool-illustration { width: 56px; height: 56px; aspect-ratio: 1; object-fit: cover; border-radius: 11px; border: 1px solid #d8e2da; background: #f8f5ed; }
.tool-copy { min-width: 0; display: grid; gap: 2px; line-height: 1.3; }
.tool-copy strong { font-size: 0.9375rem; }
.tool-copy small { color: var(--ink-soft); font-size: 0.75rem; line-height: 1.35; }
.tool-link.is-unavailable { background: #f3f4f3; border-style: dashed; }
.tool-link.is-unavailable .tool-illustration { filter: grayscale(.7); opacity: .78; }
.status-badge { display: inline-block; margin: 0 4px 2px 0; padding: 1px 5px; border: 1px solid #7d8b83; border-radius: 999px; color: #45534b; background: #fff; font-size: 0.75rem; font-weight: 700; white-space: nowrap; }
.app-chrome { position: sticky; top: 0; z-index: 20; background: var(--surface); }
.app-chrome .topbar, .app-chrome .tabs { position: static; }

@media (max-width: 720px) {
  .tabs { padding-inline: 8px; }
}

@media (max-width: 390px) {
  .tab-links { width: calc(100vw - 16px); right: -4px; }
  .tool-grid { grid-template-columns: 1fr; }
}

@media (max-width: 360px) {
  .tabs { gap: 0; padding-inline: 4px; }
  .tab { padding-inline: 8px; font-size: 0.875rem; }
  .more-menu > summary { padding-inline: 8px; font-size: 0.875rem; }
}

/* 子頁共用的返回列 */
.subpage-back { padding: 12px 16px 0; max-width: 1100px; margin: 0 auto; }
.subpage-back a { font-size: 0.875rem; color: var(--ink-soft); text-decoration: none; }
.subpage-back a:hover { color: var(--green); }

main { padding: 20px 16px 80px; max-width: 1100px; margin: 0 auto; }

.view { display: none; }
.view.is-active { display: block; }

.view-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 16px;
  flex-wrap: wrap;
}

#view-record > .view-head { align-items: center; }
.seat-heading { display: flex; align-items: center; gap: 12px; min-width: 0; }
.seat-heading-art {
  width: 84px;
  height: 84px;
  aspect-ratio: 1;
  object-fit: cover;
  flex: 0 0 auto;
  border: 1px solid #d5e1d8;
  border-radius: 18px;
  background: #faf7ef;
  box-shadow: 0 8px 22px rgba(29, 43, 36, .08);
}

.hint { color: var(--ink-soft); font-size: 0.875rem; margin-top: 4px; }
.view-actions { display: flex; gap: 8px; flex-wrap: wrap; }

/* ---- 按鈕 ---- */

.btn {
  font: inherit;
  font-weight: 600;
  border-radius: 10px;
  border: 1px solid var(--line);
  background: var(--surface);
  color: var(--ink);
  padding: 9px 14px;
  min-height: 44px;
  cursor: pointer;
}

.btn:hover { background: var(--surface-2); }
.btn-primary { background: var(--green); border-color: var(--green); color: #fff; }
.btn-primary:hover { background: #26654b; }
.btn-ghost { background: var(--surface); }
.btn-sm { padding: 7px 10px; min-height: 44px; font-size: 0.875rem; }
.btn.is-on { background: var(--green-soft); border-color: var(--green); color: var(--green); }

.linkbtn {
  font: inherit;
  font-size: 0.8125rem;
  background: none;
  border: none;
  color: var(--ink-soft);
  text-decoration: underline;
  cursor: pointer;
  padding: 8px;
  min-height: 44px;
  min-width: 44px;
}

:where(a, button, input, select, summary, [tabindex]):focus-visible {
  outline: 3px solid #84b9a0;
  outline-offset: 2px;
}

.demo-banner, .availability-card {
  display: flex;
  align-items: center;
  gap: 16px;
  background: linear-gradient(135deg, #f7fbf8, #fff8ee);
  border: 1px solid #c9ddd0;
  border-radius: var(--radius);
  padding: 14px 16px;
  margin-bottom: 18px;
}
.demo-banner img, .availability-card img { flex: 0 0 auto; }
.demo-banner div { flex: 1; }
.demo-banner p { color: var(--ink-soft); font-size: 0.8125rem; }
.availability-card { max-width: 760px; margin: 30px auto; padding: 24px; align-items: flex-start; }
.availability-card h2 { margin-bottom: 8px; }
.availability-card p { margin-bottom: 12px; }
.eyebrow { color: var(--green); font-size: 0.75rem; font-weight: 700; letter-spacing: .12em; }

.lock-screen { position: fixed; inset: 0; z-index: 100; display: grid; place-items: center; padding: 18px; background: rgba(20, 32, 26, .72); backdrop-filter: blur(8px); }
.lock-card { width: min(430px, 100%); max-height: calc(100vh - 36px); overflow-y: auto; background: var(--surface); border-radius: 20px; padding: 24px; box-shadow: 0 20px 70px rgba(20, 32, 26, .35); display: grid; gap: 12px; }
.lock-card img { justify-self: center; }
.lock-card h1 { margin: 0; font-size: 1.375rem; line-height: 1.35; }
.lock-card label { display: grid; gap: 5px; font-weight: 600; }
.lock-card input { min-height: 48px; padding: 10px 12px; border: 1px solid var(--line); border-radius: 10px; font: inherit; font-size: 1.125rem; }
.lock-error { min-height: 1.5em; color: var(--red); font-size: 0.875rem; }
.lock-note { color: var(--ink-soft); font-size: 0.75rem; }

/* ---- 座位表 ---- */

.board {
  text-align: center;
  font-size: 0.8125rem;
  letter-spacing: .3em;
  color: var(--ink-soft);
  background: var(--surface-2);
  border: 1px dashed var(--line);
  border-radius: 10px;
  padding: 8px;
  margin-bottom: 14px;
}

.board-bottom { margin: 14px 0 0; }

.seating {
  display: grid;
  gap: 10px;
}

.seat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 12px 8px;
  text-align: center;
  cursor: pointer;
  box-shadow: var(--shadow);
  transition: transform .08s ease, border-color .12s ease;
  min-height: 136px;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 4px;
}

.seat:active { transform: scale(.97); }
.seat.is-selected { border-color: var(--green); background: var(--green-soft); }
.seat.flash-up { animation: flashUp .5s ease; }
.seat.flash-down { animation: flashDown .5s ease; }

/*
 * 不參與記錄。位子留著、灰階、虛線邊框，不可點。
 * 刻意不用紅色或警告色——紅色留給「永久刪除」那種不可逆動作，
 * 兩者長得像的話，同學瞄到座位表就會自己腦補成「他被停權了」。
 */
.seat.is-optout {
  background: var(--surface-2);
  border-style: dashed;
  cursor: default;
  opacity: .7;
}
.seat.is-optout .seat-name { color: var(--ink-soft); font-weight: 400; }

@keyframes flashUp {
  0% { background: var(--green-soft); }
  100% { background: var(--surface); }
}
@keyframes flashDown {
  0% { background: var(--amber-soft); }
  100% { background: var(--surface); }
}

.seat-no { font-size: 0.75rem; color: var(--ink-soft); }
.seat-avatar {
  width: 44px;
  height: 44px;
  aspect-ratio: 1;
  object-fit: cover;
  align-self: center;
  border: 1px solid #d7e5dc;
  border-radius: 50%;
  background: #f8f5ed;
}
.seat-name { font-weight: 700; font-size: 0.9375rem; }
.seat-score { font-size: 1.25rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.seat-score.pos { color: var(--green); }
.seat-score.neg { color: var(--red); }
.seat-score.zero { color: var(--ink-soft); }
.seat-today { font-size: 0.75rem; color: var(--ink-soft); }

/* 手機直握時，座位表仍維持原本的排列，只把字級與留白收緊 */
@media (max-width: 560px) {
  main { padding: 16px 10px 80px; }
  .seat-heading { gap: 9px; }
  .seat-heading-art { width: 64px; height: 64px; border-radius: 14px; }
  .seating { gap: 6px; }
  .seat { padding: 7px 2px; min-height: 112px; border-radius: 10px; gap: 2px; }
  .seat-avatar { width: 34px; height: 34px; }
  .seat-name { font-size: 0.8125rem; letter-spacing: -.02em; }
  .seat-score { font-size: 1.0625rem; }
  .seat-no, .seat-today { font-size: 0.75rem; }
  .demo-banner { align-items: flex-start; }
  .demo-banner img { width: 70px; height: auto; }
  .demo-banner .btn { display: none; }
  .availability-card { flex-direction: column; margin-top: 12px; }
}

.multibar {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--green-soft);
  border: 1px solid var(--green);
  border-radius: 10px;
  padding: 8px 12px;
  margin-bottom: 12px;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--green);
  flex-wrap: wrap;
}

/* ---- 記錄面板 ---- */

.sheet { position: fixed; inset: 0; z-index: 40; display: flex; align-items: flex-end; justify-content: center; }
.sheet-backdrop { position: absolute; inset: 0; background: rgba(20, 32, 26, .45); }

.sheet-panel {
  position: relative;
  background: var(--surface);
  width: 100%;
  max-width: 640px;
  max-height: 88vh;
  overflow-y: auto;
  border-radius: 18px 18px 0 0;
  padding: 18px 18px 24px;
  box-shadow: 0 -8px 40px rgba(20, 32, 26, .2);
}

@media (min-width: 640px) {
  .sheet { align-items: center; }
  .sheet-panel { border-radius: 18px; }
}

.sheet-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 14px;
}

.behavior-group { margin-bottom: 16px; }

.group-title { font-size: 0.8125rem; margin-bottom: 8px; }
.group-title.positive { color: var(--green); }
.group-title.improve { color: var(--amber); }

.behaviors { display: grid; grid-template-columns: repeat(auto-fill, minmax(104px, 1fr)); gap: 8px; }

.bcard {
  font: inherit;
  border: 1px solid var(--line);
  border-radius: 12px;
  background: var(--surface);
  padding: 12px 6px;
  cursor: pointer;
  text-align: center;
  min-height: 84px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
}

.bcard:hover { background: var(--surface-2); }
.bcard .icon { font-size: 1.375rem; }
.behavior-art {
  width: 52px;
  height: 52px;
  aspect-ratio: 1;
  object-fit: cover;
  border: 1px solid rgba(47, 122, 91, .16);
  border-radius: 12px;
  background: #f8f5ed;
}
.bcard .label { font-size: 0.8125rem; font-weight: 600; }
.bcard .delta { font-size: 0.8125rem; font-weight: 700; font-variant-numeric: tabular-nums; }
.bcard.positive { border-color: #bcdcca; }
.bcard.positive .delta { color: var(--green); }
.bcard.improve { border-color: #eddcbe; }
.bcard.improve .delta { color: var(--amber); }

.sheet-foot { font-size: 0.75rem; color: var(--ink-soft); border-top: 1px solid var(--line); padding-top: 12px; }

/* ---- 提示 ---- */

.toast {
  position: fixed;
  left: 50%;
  transform: translateX(-50%);
  bottom: 20px;
  background: var(--ink);
  color: #fff;
  padding: 10px 12px 10px 16px;
  border-radius: 999px;
  display: flex;
  align-items: center;
  gap: 12px;
  z-index: 50;
  box-shadow: 0 8px 30px rgba(20, 32, 26, .3);
  font-size: 0.875rem;
  max-width: calc(100vw - 32px);
}

.btn-undo { background: rgba(255,255,255,.16); border: none; color: #fff; }
.btn-undo:hover { background: rgba(255,255,255,.28); }

/* ---- 儀表板 ---- */

.alerts { display: grid; gap: 10px; margin-bottom: 18px; }

.alert {
  border-radius: 12px;
  padding: 12px 14px;
  border: 1px solid var(--amber);
  background: var(--amber-soft);
}

.alert.student { border-color: var(--red); background: var(--red-soft); }
.alert h4 { font-size: 0.9375rem; margin-bottom: 2px; }
.alert p { font-size: 0.8125rem; color: var(--ink-soft); }
.alert-empty { border: 1px solid var(--line); background: var(--surface); color: var(--ink-soft); border-radius: 12px; padding: 12px 14px; font-size: 0.875rem; }

.stats { display: grid; grid-template-columns: repeat(auto-fit, minmax(140px, 1fr)); gap: 10px; margin-bottom: 18px; }

.stat {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 14px;
  box-shadow: var(--shadow);
}

.stat .k { font-size: 0.8125rem; color: var(--ink-soft); }
.stat .v { font-size: 1.625rem; font-weight: 700; font-variant-numeric: tabular-nums; }

.panel {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 16px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}

.panel h3 { font-size: 0.9375rem; margin-bottom: 12px; }

.trend { display: flex; align-items: flex-end; gap: 6px; height: 160px; overflow-x: auto; }

.tcol { flex: 1 1 0; min-width: 34px; display: flex; flex-direction: column; align-items: center; gap: 4px; height: 100%; justify-content: flex-end; }
.tbars { flex: 1; width: 100%; display: flex; align-items: flex-end; gap: 3px; }
.tbar { flex: 1; border-radius: 4px 4px 0 0; min-height: 2px; }
.tbar.p { background: var(--green); }
.tbar.i { background: #e0a35a; }
.tlabel { font-size: 0.75rem; color: var(--ink-soft); }

/* ---- 表格 ---- */

.filters { display: flex; gap: 14px; flex-wrap: wrap; margin-bottom: 14px; font-size: 0.875rem; align-items: center; }
.filters label { display: flex; align-items: center; gap: 6px; color: var(--ink-soft); }
.filters .check { gap: 6px; }

table { width: 100%; border-collapse: collapse; font-size: 0.875rem; }
th, td { text-align: left; padding: 9px 10px; border-bottom: 1px solid var(--line); vertical-align: middle; }
th { font-size: 0.75rem; color: var(--ink-soft); font-weight: 600; }
tbody tr:hover { background: var(--surface-2); }
tr.voided { opacity: .45; text-decoration: line-through; }

.logtable, .studenttable {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow-x: auto;
  box-shadow: var(--shadow);
}

.pill { display: inline-block; padding: 2px 8px; border-radius: 999px; font-size: 0.75rem; font-weight: 600; }
.pill.positive { background: var(--green-soft); color: var(--green); }
.pill.improve { background: var(--amber-soft); color: var(--amber); }
.pill.redeem { background: #ece6f6; color: #5b4a8a; }

.num { font-variant-numeric: tabular-nums; text-align: right; }
.empty { padding: 24px; text-align: center; color: var(--ink-soft); font-size: 0.875rem; }

/* ---- 學生詳情 ---- */

.detail-stats { display: flex; gap: 10px; margin-bottom: 14px; flex-wrap: wrap; }
.detail-stat { flex: 1 1 90px; background: var(--surface-2); border-radius: 10px; padding: 10px; text-align: center; }
.detail-stat .k { font-size: 0.75rem; color: var(--ink-soft); }
.detail-stat .v { font-size: 1.25rem; font-weight: 700; }
.timeline { list-style: none; padding: 0; margin: 0; max-height: 320px; overflow-y: auto; }
.timeline li { display: flex; gap: 10px; padding: 8px 0; border-bottom: 1px solid var(--line); font-size: 0.875rem; align-items: center; }
.timeline .t { color: var(--ink-soft); font-size: 0.75rem; min-width: 92px; }
.timeline .d { margin-left: auto; font-weight: 700; font-variant-numeric: tabular-nums; }
.timeline .d.pos { color: var(--green); }
.timeline .d.neg { color: var(--amber); }

.notice {
  background: var(--green-soft);
  border: 1px solid #bcdcca;
  border-radius: 10px;
  padding: 10px 12px;
  font-size: 0.8125rem;
  color: var(--green);
  margin-bottom: 14px;
}

/* ---- 頁尾 ---- */

.foot {
  border-top: 1px solid var(--line);
  padding: 18px 16px 40px;
  text-align: center;
  color: var(--ink-soft);
  font-size: 0.8125rem;
  display: grid;
  gap: 6px;
  justify-items: center;
}

/*
 * 行內小表單。原本各頁自己複製一份（roster / backup / comments 各一），
 * 結果 contact.html 只載 style.css 就拿到一排沒有樣式的裸元件——
 * 這種東西只能有一份，放在這裡。
 */
.inline-form {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
  margin: 12px 0;
  font-size: 0.875rem;
}
.inline-form label {
  display: flex;
  align-items: center;
  gap: 6px;
  color: var(--ink-soft);
}
.inline-form input,
.inline-form select {
  font: inherit;
  padding: 8px 10px;
  border: 1px solid var(--line);
  border-radius: 10px;
  background: var(--surface);
  color: var(--ink);
  min-height: 44px;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    scroll-behavior: auto !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .01ms !important;
  }
}
.inline-form input[type="number"] { width: 84px; }
.inline-form input[type="text"] { width: 140px; }

/* ---- Apps Script 版的登入遮罩（js/gas-auth.js 動態插入）----
   只有 STORE_BACKEND = 'gas' 且尚未登入時才會出現。 */
.gas-signin-mask {
  position: fixed;
  inset: 0;
  z-index: 9999;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(15, 23, 42, .55);
}
.gas-signin-box {
  width: min(420px, 100%);
  padding: 28px 24px;
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 18px 48px rgba(15, 23, 42, .28);
  text-align: center;
}
.gas-signin-box h2 { margin: 0 0 12px; font-size: 1.25rem; }
.gas-signin-box p { margin: 0 0 18px; color: var(--ink-soft); line-height: 1.7; }
.gas-signin-btn { display: flex; justify-content: center; min-height: 44px; }
.gas-signin-note { margin: 18px 0 0 !important; font-size: 0.8125rem; }