:root {
  /* 中式留白配色 —— 宣纸 / 墨 / 朱砂 */
  --bg: #f3efe7;            /* 宣纸暖白 */
  --bg-grad-top: #ece4d6;
  --card: #fffdf8;
  --card-soft: #f6f1e7;
  --ink: #2a2520;          /* 墨色 */
  --ink-soft: #8a8073;
  --ink-faint: #b6ac9c;
  --accent: #9d4030;       /* 朱砂 / 赭红 印章色 */
  --accent-dark: #843325;
  --accent-soft: #f1e3dd;
  --primary: #38332d;      /* 墨色 主按钮 */
  --primary-dark: #24201b;
  --line: #ece6d9;
  --line-strong: #ddd5c5;
  --radius: 14px;
  --radius-sm: 9px;
  --shadow: 0 2px 14px rgba(74, 58, 38, 0.05);
  --serif: "Songti SC", "STSong", "Songti TC", "SimSun", "Noto Serif CJK SC", serif;
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  -webkit-font-smoothing: antialiased;
}

body {
  min-height: 100vh;
  background: linear-gradient(180deg, var(--bg-grad-top) 0%, var(--bg) 240px);
}

/* ---------- 返回按钮（悬浮在设计页左上） ---------- */
.back-fab {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  margin: 0 0 8px -2px;
  border: 1px solid var(--line-strong);
  border-radius: 50%;
  background: var(--card);
  font-size: 26px;
  line-height: 1;
  color: var(--ink);
  cursor: pointer;
  box-shadow: var(--shadow);
}
.back-fab:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- 布局 ---------- */
.app {
  max-width: 430px;
  margin: 0 auto;
  padding: 18px 18px 44px;
}
.screen { display: none; }
.screen--active { display: block; }

/* ---------- 卡片 ---------- */
.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  padding: 22px 20px 24px;
  margin-bottom: 18px;
  box-shadow: var(--shadow);
}
.card--intro {
  background: transparent;
  border: none;
  box-shadow: none;
  padding: 8px 4px 14px;
}
.card__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.card__title {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 1px;
  margin: 0 0 18px;
  position: relative;
  padding-left: 12px;
}
.card__title::before {
  content: "";
  position: absolute;
  left: 0; top: 3px;
  width: 3px; height: 16px;
  background: var(--accent);
  border-radius: 2px;
}
.card__head .card__title { margin-bottom: 0; }
.card__meta { font-size: 13px; color: var(--ink-soft); margin: 8px 0 0; letter-spacing: .5px; }
.card__hint { font-size: 13px; color: var(--accent); font-weight: 600; margin: 12px 0 0; }

.hero__title {
  font-family: var(--serif);
  font-size: 25px;
  font-weight: 800;
  letter-spacing: 3px;
  margin: 0 0 14px;
}
.hero__sub { font-size: 14px; line-height: 1.9; color: var(--ink-soft); margin: 0; letter-spacing: .5px; }
.asset-status {
  display: inline-flex;
  align-items: center;
  min-height: 26px;
  margin: 12px 0 0;
  padding: 5px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: rgba(255, 253, 248, .62);
  color: var(--ink-soft);
  font-size: 12px;
  letter-spacing: .5px;
}
.asset-status--ready {
  border-color: rgba(157, 64, 48, .18);
  background: var(--accent-soft);
  color: var(--accent);
}
.asset-status--error {
  border-color: rgba(157, 64, 48, .34);
  color: var(--accent);
}

/* ---------- 表单 ---------- */
.field { display: block; margin-bottom: 18px; }
.field__label { display: block; font-size: 13px; color: var(--ink-soft); margin-bottom: 8px; letter-spacing: 1px; }
.field__input {
  width: 100%;
  height: 50px;
  border: 1px solid var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--card-soft);
  padding: 0 14px;
  font-size: 17px;
  color: var(--ink);
  outline: none;
  transition: border-color .15s, box-shadow .15s;
}
.field__input:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(157, 64, 48, 0.1);
}
.field__input[aria-invalid="true"] {
  border-color: var(--accent);
  background: #fff8f5;
}
.field__input--select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%238a8073' d='M1 1l5 5 5-5'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 14px center;
  padding-right: 36px;
  cursor: pointer;
}
.field--inline { display: flex; align-items: center; gap: 12px; }
.field--inline .field__input { flex: 1; height: 44px; font-size: 15px; }
.field__label--inline {
  margin-bottom: 0;
  white-space: nowrap;
  background: var(--card-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  color: var(--ink);
  font-size: 14px;
  letter-spacing: 1px;
}

.hint { font-size: 12px; color: var(--ink-faint); margin: 4px 0 18px; line-height: 1.6; letter-spacing: .5px; }
.dimension-feedback {
  min-height: 20px;
  margin: -6px 0 18px;
  color: var(--accent);
  font-size: 12px;
  line-height: 1.55;
  letter-spacing: .5px;
}
.dimension-feedback--ok { color: #4f7963; }

/* ---------- 统计卡 ---------- */
.stats { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.stat {
  background: var(--card-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 16px;
}
.stat:last-child { grid-column: 1 / -1; }
.stat__value { font-family: var(--serif); font-size: 21px; font-weight: 800; letter-spacing: 1px; }
.stat__label { font-size: 12px; color: var(--ink-soft); margin-top: 5px; letter-spacing: 1px; }

/* ---------- 按钮 ---------- */
.btn {
  width: 100%;
  height: 54px;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 4px;
  cursor: pointer;
  transition: transform .05s, background .15s, opacity .15s;
}
.btn:active { transform: scale(0.985); }
.btn:focus-visible,
.back-fab:focus-visible,
.field__input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.btn--primary { background: var(--primary); color: #f3efe7; }
.btn--primary:hover { background: var(--primary-dark); }
.btn--primary:disabled { opacity: .4; cursor: not-allowed; }
.btn--ghost {
  height: 42px;
  border-radius: 6px;
  background: transparent;
  color: var(--ink);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 2px;
  border: 1px solid var(--line-strong);
}
.btn--ghost:hover { background: var(--card-soft); border-color: var(--accent); color: var(--accent); }

.design-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 16px; }
.design-actions .btn--ghost {
  flex: 1 1 auto;
  min-width: 0;
  padding: 0 8px;
  font-size: 13px;
  letter-spacing: 1px;
  white-space: nowrap;
}
.preview-actions { flex-wrap: nowrap; }
.preview-actions .btn--ghost { flex: 1 1 0; }

/* ---------- 徽章 / 当前 ---------- */
.badge {
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 700;
  padding: 4px 12px;
  border-radius: 4px;
  letter-spacing: 1px;
}
.current { display: flex; align-items: center; gap: 6px; margin: 16px 0 12px; font-size: 14px; }
.current__label { color: var(--ink-soft); letter-spacing: 1px; }
.current__name { font-weight: 700; letter-spacing: 1px; }

/* ---------- 预览网格 ---------- */
.preview-wrap {
  background: var(--card-soft);
  border: 1px solid var(--line);
  border-radius: var(--radius-sm);
  padding: 12px;
}
.grid {
  display: grid;
  gap: 2px;
  width: 100%;
  aspect-ratio: 3 / 2; /* JS 会按真实比例覆盖 */
  background: #cfc6b4;
  border-radius: 4px;
  overflow: hidden;
}
.tile {
  position: relative;
  display: block;
  border: 0;
  padding: 0;
  font: inherit;
  background-size: 100% 100%;
  background-position: center;
  cursor: pointer;
  image-rendering: auto;
  -webkit-optimize-contrast: optimize-contrast;
  outline: 2px solid transparent;
  outline-offset: -2px;
}
.tile:hover { outline-color: rgba(157, 64, 48, 0.5); }
.tile:focus-visible {
  outline-color: var(--accent);
  z-index: 3;
}
.tile--selected { outline-color: var(--accent); z-index: 2; }
.tile--selected::after {
  content: "";
  position: absolute;
  inset: 0;
  box-shadow: inset 0 0 0 2px var(--card);
}

/* ---------- 选择区 ---------- */
.series-desc { font-size: 13px; color: var(--ink-soft); line-height: 1.8; margin: 12px 0 10px; letter-spacing: .5px; }

.swatch__title { font-size: 14px; font-weight: 700; margin: 20px 0 14px; letter-spacing: 1px; }
.swatches {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.swatches--empty { display: block; }
.swatch {
  position: relative;
  display: block;
  width: 100%;
  border: 2px solid transparent;
  padding: 0;
  font: inherit;
  border-radius: 6px;
  overflow: hidden;
  cursor: pointer;
  background-size: cover;
  background-position: center;
  aspect-ratio: 1 / 1;
  transition: border-color .1s, transform .05s;
}
.swatch:active { transform: scale(0.96); }
.swatch--active { border-color: var(--accent); }
.swatch:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 3px;
}
.swatch__caption {
  position: absolute;
  left: 0; right: 0; bottom: 0;
  background: linear-gradient(180deg, transparent, rgba(0,0,0,0.55));
  color: #fff;
  padding: 12px 4px 3px;
  font-size: 10px;
  line-height: 1.25;
  text-align: center;
}
.swatch__code { font-weight: 700; display: block; }
.swatch__name { opacity: .9; }
.swatch--active .swatch__check {
  position: absolute;
  top: 3px; right: 3px;
  width: 16px; height: 16px;
  background: var(--accent);
  border-radius: 50%;
  color: #fff;
  font-size: 11px;
  line-height: 16px;
  text-align: center;
}

/* ---------- 用料小结 ---------- */
.card--summary .summary-row {
  display: flex;
  justify-content: space-between;
  font-size: 14px;
  padding: 9px 0;
  color: var(--ink-soft);
  border-bottom: 1px solid var(--line);
  letter-spacing: .5px;
}
.summary-row span:last-child { color: var(--ink); font-weight: 600; }
.summary-row--total { border-bottom: none; padding-top: 14px; }
.summary-row--total span { font-family: var(--serif); font-size: 18px; font-weight: 800; color: var(--ink); }
.summary-row--total span:last-child { color: var(--accent); }

/* ---------- 各花色用量 ---------- */
.usage__title { font-size: 14px; font-weight: 700; margin: 18px 0 12px; letter-spacing: 1px; }
.usage-list { display: flex; flex-direction: column; gap: 8px; }
.usage-row {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  letter-spacing: .5px;
}
.usage-row__swatch {
  width: 22px;
  height: 22px;
  flex: 0 0 auto;
  border-radius: 5px;
  border: 1px solid var(--line-strong);
  background-size: cover;
  background-position: center;
}
.usage-row__name { flex: 1; color: var(--ink); }
.usage-row__count { font-weight: 700; color: var(--accent); white-space: nowrap; }
.usage-empty { font-size: 13px; color: var(--ink-faint); margin: 4px 0 0; letter-spacing: .5px; }
.empty-state {
  margin: 0;
  padding: 14px;
  border: 1px dashed var(--line-strong);
  border-radius: var(--radius-sm);
  background: var(--card-soft);
  color: var(--ink-soft);
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: .5px;
}

/* ---------- 提示气泡 ---------- */
.toast {
  position: fixed;
  left: 50%;
  bottom: 28px;
  transform: translateX(-50%) translateY(20px);
  background: rgba(42, 37, 32, 0.94);
  color: #f3efe7;
  font-size: 13px;
  letter-spacing: 1px;
  padding: 10px 18px;
  border-radius: 6px;
  opacity: 0;
  pointer-events: none;
  transition: opacity .2s, transform .2s;
  z-index: 50;
}
.toast--show { opacity: 1; transform: translateX(-50%) translateY(0); }