/*
[INPUT]: 依赖 index.html 的 DOM 类名和 CSS 变量、getstampstack.vercel.app 的白底 demo 视觉、app.js 的翻牌状态类
[OUTPUT]: 对外提供极简移动优先 TodayCard 布局、stampstack-like coverflow、圆角质感牌背、答案正面、10x10 网格和点击翻牌样式
[POS]: 项目视觉层，只负责形态、动效和响应式，不拥有 decision/options 数据和随机图案算法
[PROTOCOL]: 变更时更新此头部，然后检查 CLAUDE.md
*/
:root {
  --page: #ffffff;
  --ink: #252525;
  --muted: #8e8e8e;
  --quiet: #c7c7c7;
  --line: #e9e9e9;
  --soft: #f8f8f8;
  --shadow: 0 18px 42px rgba(30, 30, 30, 0.08);
  --sans: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, "Liberation Mono", monospace;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html,
body {
  margin: 0;
  min-height: 100%;
  background:
    radial-gradient(circle at 18% 4%, rgba(64, 114, 255, 0.08), transparent 22%),
    radial-gradient(circle at 77% 0%, rgba(95, 213, 0, 0.08), transparent 22%),
    radial-gradient(circle at 97% 4%, rgba(255, 101, 72, 0.08), transparent 20%),
    var(--page);
  color: var(--ink);
  font-family: var(--sans);
}

body {
  min-height: 100vh;
  padding: 32px 20px 34px;
  overflow-x: hidden;
}

button,
input,
textarea {
  font: inherit;
}

button {
  min-height: 36px;
  border: 1px solid #171717;
  border-radius: 14px;
  background: #171717;
  color: #fafafa;
  padding: 10px 18px;
  font-size: 14px;
  font-weight: 520;
  letter-spacing: -0.4px;
  cursor: pointer;
  transition: transform 160ms ease, opacity 160ms ease, background 160ms ease;
}

button:hover { transform: translateY(-1px); }
button:active { transform: translateY(0); }

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
.deck-shell:focus-visible {
  outline: 3px solid rgba(41, 93, 246, 0.18);
  outline-offset: 3px;
}

button.secondary,
button.ghost {
  border-color: #e5e5e5;
  background: #fff;
  color: #0a0a0a;
}

button.ghost {
  width: 36px;
  min-width: 36px;
  padding: 0;
  display: inline-grid;
  place-items: center;
  border-radius: 50%;
}

.app {
  width: min(100%, 430px);
  margin: 0 auto;
  display: grid;
  gap: 24px;
}

.hero {
  display: grid;
  justify-items: center;
}

.brand {
  display: grid;
  justify-items: center;
}

.brand h1 {
  margin: 0;
  font-size: 24px;
  font-weight: 780;
  line-height: 1;
  letter-spacing: -0.9px;
}

.stage {
  display: grid;
  gap: 0;
}

.deck-shell {
  position: relative;
  height: 372px;
  width: 100%;
  margin-inline: 0;
  perspective: 900px;
  touch-action: pan-y;
  user-select: none;
  cursor: grab;
  overflow: visible;
}

.deck-shell.is-dragging { cursor: grabbing; }

.deck {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  transform-style: preserve-3d;
}

.card {
  --card-bg: #fff;
  --card-cell: #f2f2f2;
  --card-mark: #00c9a7;
  --card-text: #666;
  --card-muted: #a4a4a4;
  --card-frame: #00c9a7;
  --lift: 0px;
  position: absolute;
  width: 240px;
  aspect-ratio: 0.76;
  color: var(--card-text);
  opacity: var(--opacity);
  pointer-events: auto;
  cursor: pointer;
  transform: translateY(calc(-20px + var(--lift))) translateX(var(--x)) translateZ(var(--z)) rotateY(var(--ry)) rotateZ(var(--rz)) scale(var(--scale));
  transform-origin: center;
  transition: transform 450ms cubic-bezier(0.25, 0.46, 0.45, 0.94), opacity 450ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
  will-change: transform, opacity;
}

.deck-shell.is-dragging .card {
  transition: none;
}

@media (hover: hover) and (pointer: fine) {
  .card:hover {
    --lift: -8px;
  }
}

.card-inner {
  position: absolute;
  inset: 0;
  border: 10px solid color-mix(in srgb, var(--card-frame), #fff 18%);
  border-radius: 28px;
  background:
    linear-gradient(145deg, rgba(255, 255, 255, 0.68), rgba(255, 255, 255, 0.08)),
    var(--card-frame);
  box-shadow:
    0 22px 32px rgba(31, 31, 31, 0.1),
    0 8px 14px rgba(31, 31, 31, 0.08);
  transform-style: preserve-3d;
  transform-origin: center;
  transition: transform 560ms cubic-bezier(0.2, 0.78, 0.12, 1);
  transform: translateZ(0);
  will-change: transform;
}

.card-inner::before {
  content: "";
  position: absolute;
  inset: -10px;
  z-index: 4;
  pointer-events: none;
  border-radius: 31px;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.58),
    inset 0 -14px 24px rgba(0, 0, 0, 0.08),
    0 1px 0 rgba(255, 255, 255, 0.9);
}

.card.is-flipped .card-inner {
  transform: translateZ(0) rotateY(180deg);
}

.stamp-face {
  position: absolute;
  inset: 0;
  display: grid;
  grid-template-rows: auto 1fr auto;
  gap: 12px;
  padding: 18px;
  border-radius: 20px;
  background:
    linear-gradient(180deg, rgba(255, 255, 255, 0.96), rgba(250, 250, 250, 0.9)),
    #fff;
  box-shadow:
    inset 0 1px 0 rgba(255, 255, 255, 0.9),
    inset 0 -1px 0 rgba(0, 0, 0, 0.04),
    inset 0 0 0 1px rgba(0, 0, 0, 0.045);
  overflow: hidden;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
}

.stamp-face::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(120deg, rgba(255, 255, 255, 0.42), transparent 42%),
    repeating-linear-gradient(0deg, rgba(0, 0, 0, 0.018) 0 1px, transparent 1px 5px);
  pointer-events: none;
}

.card-front {
  transform: rotateY(180deg);
}

.card-top,
.card-bottom,
.option-reveal,
.answer-copy {
  position: relative;
  z-index: 2;
}

.card-top,
.card-bottom {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  color: var(--card-muted);
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1;
}

.card-title,
.card-id,
.card-signature,
.card-date {
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.card-title {
  max-width: 112px;
}

.card-date {
  flex: 0 0 auto;
}

.card-signature {
  max-width: 112px;
}

.grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  width: min(100%, 184px);
  gap: 4px;
  align-self: center;
  justify-self: center;
}

.cell {
  aspect-ratio: 1;
  border-radius: 3px;
  background: var(--card-cell);
}

.cell.is-on {
  background: var(--card-mark);
}

.option-reveal,
.answer-copy {
  align-self: center;
  display: grid;
  gap: 8px;
  text-align: center;
}

.option-label {
  color: var(--card-muted);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.option-text,
.answer-text {
  margin: 0;
  color: #666;
  font-size: 20px;
  font-weight: 680;
  line-height: 1.05;
  letter-spacing: -0.5px;
  overflow-wrap: anywhere;
}

.option-text.sealed {
  color: #777;
  font-size: 18px;
}

.answer-mark {
  align-self: center;
  justify-self: center;
  width: 104px;
  aspect-ratio: 1;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 7px;
  transform: rotate(-7deg);
}

.answer-mark span {
  border-radius: 6px;
  background: var(--card-frame);
}

.answer-mark span:nth-child(1) {
  grid-column: 1 / 3;
  grid-row: 1 / 3;
}

.answer-mark span:nth-child(2) {
  grid-column: 2 / 4;
  grid-row: 2 / 4;
  opacity: 0.78;
}

.answer-mark span:nth-child(3) {
  grid-column: 1 / 2;
  grid-row: 3 / 4;
  opacity: 0.62;
}

.control-panel {
  display: grid;
  gap: 12px;
}

.field {
  display: grid;
  gap: 8px;
}

.field label,
.advanced summary {
  color: #989897;
  font-size: 12px;
  font-weight: 560;
  line-height: 20px;
  letter-spacing: -0.2px;
}

.field input,
.field textarea {
  width: 100%;
  border: 1px solid #e5e5e5;
  border-radius: 16px;
  background: #fff;
  color: #252525;
  padding: 14px 16px;
  font-size: 14px;
  font-weight: 500;
  line-height: 1.45;
  letter-spacing: -0.2px;
}

.field textarea {
  min-height: 112px;
  resize: vertical;
}

.advanced {
  display: grid;
  gap: 10px;
  margin-top: 2px;
}

.advanced summary {
  width: max-content;
  cursor: pointer;
  list-style: none;
}

.advanced summary::-webkit-details-marker {
  display: none;
}

.advanced summary::after {
  content: " +";
}

.advanced[open] summary::after {
  content: " -";
}

.empty {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  color: var(--muted);
  font-family: var(--mono);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

@media (max-width: 430px) {
  .app { gap: 22px; }

  .hero {
    gap: 0;
  }

  .deck-shell {
    height: 346px;
  }

  .card {
    width: 220px;
  }

  .card-inner {
    border-width: 9px;
  }

  .card-inner::before {
    inset: -9px;
  }

  .stamp-face {
    padding: 17px;
  }
}

@media (min-width: 860px) {
  body {
    padding-top: 50px;
  }

  .app {
    width: min(100%, 520px);
    gap: 34px;
  }

  .deck-shell {
    height: 390px;
    width: 100vw;
    margin-inline: calc(50% - 50vw);
  }

}