/* ============ 手写扫描通 - 设计系统 ============ */
:root {
  /* 浅色主题（默认） */
  --bg: #fafaf9;
  --bg-soft: #f2f1ef;
  --card: #ffffff;
  --border: #e7e5e4;
  --text: #1c1917;
  --text-2: #57534e;
  --text-3: #a8a29e;
  --accent: #7c3aed;
  --accent-2: #db2777;
  --accent-grad: linear-gradient(135deg, #7c3aed, #db2777);
  --accent-soft: rgba(124, 58, 237, 0.08);
  --warn: #f59e0b;
  --warn-soft: rgba(245, 158, 11, 0.15);
  --ok: #10b981;
  --shadow: 0 1px 3px rgba(0,0,0,.06), 0 8px 24px rgba(0,0,0,.05);
  --radius: 16px;
  --font: 'Inter', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
  --nav-h: 64px;
}

[data-theme="dark"] {
  --bg: #0d0d12;
  --bg-soft: #14141b;
  --card: #1a1a22;
  --border: #2a2a35;
  --text: #f4f4f5;
  --text-2: #a1a1aa;
  --text-3: #71717a;
  --accent: #a78bfa;
  --accent-2: #f472b6;
  --accent-soft: rgba(167, 139, 250, 0.12);
  --warn: #fbbf24;
  --warn-soft: rgba(251, 191, 36, 0.15);
  --shadow: 0 1px 3px rgba(0,0,0,.4), 0 8px 24px rgba(0,0,0,.3);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background .3s ease, color .3s ease;
  -webkit-font-smoothing: antialiased;
}

/* ============ 导航 ============ */
.nav {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--nav-h);
  background: color-mix(in srgb, var(--bg) 80%, transparent);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: 1100px;
  margin: 0 auto;
  height: 100%;
  padding: 0 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 17px;
}
.brand-icon {
  width: 32px; height: 32px;
  display: grid; place-items: center;
  border-radius: 9px;
  background: var(--accent-grad);
  font-size: 16px;
  box-shadow: 0 2px 8px rgba(124,58,237,.3);
}
.nav-actions { display: flex; align-items: center; gap: 10px; }

.quota-pill {
  display: flex; align-items: center; gap: 7px;
  padding: 6px 12px;
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  border: 1px solid transparent;
}
.quota-dot {
  width: 7px; height: 7px; border-radius: 50%;
  background: var(--ok);
  animation: pulse 2s infinite;
}
@keyframes pulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: .5; transform: scale(.85); }
}

.theme-toggle, .lang-toggle {
  border: 1px solid var(--border);
  background: var(--card);
  color: var(--text-2);
  width: 38px; height: 38px;
  border-radius: 10px;
  cursor: pointer;
  display: grid; place-items: center;
  transition: all .2s ease;
}
.theme-toggle:hover, .lang-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}
.lang-toggle { width: auto; padding: 0 12px; font-weight: 600; font-size: 13px; }
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }
.theme-toggle svg { width: 18px; height: 18px; }

/* ============ Hero ============ */
.hero {
  padding: 72px 24px 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(600px 300px at 20% 0%, var(--accent-soft), transparent),
    radial-gradient(600px 300px at 80% 10%, var(--warn-soft), transparent);
  pointer-events: none;
}
.hero-inner { position: relative; max-width: 800px; margin: 0 auto; }

.hero-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 8px;
  margin-top: 24px;
}
.hero-tags span {
  padding: 5px 12px;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-2);
  transition: all .2s ease;
}
.hero-tags span:hover {
  border-color: var(--accent);
  color: var(--accent);
  transform: translateY(-1px);
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 16px;
  border-radius: 999px;
  background: var(--card);
  border: 1px solid var(--border);
  font-size: 13px;
  font-weight: 500;
  color: var(--text-2);
  margin-bottom: 24px;
  animation: fadeUp .6s ease both;
}
.badge-dot {
  width: 8px; height: 8px; border-radius: 50%;
  background: var(--accent-grad);
  display: inline-block;
}
.hero-title {
  font-size: clamp(32px, 5vw, 52px);
  font-weight: 800;
  letter-spacing: -0.02em;
  line-height: 1.15;
  margin-bottom: 18px;
  animation: fadeUp .6s ease .1s both;
}
.hero-title .grad {
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-sub {
  font-size: clamp(15px, 2vw, 17px);
  color: var(--text-2);
  max-width: 620px;
  margin: 0 auto;
  animation: fadeUp .6s ease .2s both;
}

@keyframes fadeUp {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* ============ 工作区 ============ */
.workspace {
  max-width: 900px;
  margin: 0 auto;
  padding: 0 24px 60px;
}
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  overflow: hidden;
}
.upload-card { padding: 24px; animation: fadeUp .5s ease .3s both; }

.drop-zone {
  border: 2px dashed var(--border);
  border-radius: 12px;
  padding: 56px 24px;
  text-align: center;
  cursor: pointer;
  transition: all .25s ease;
  background: var(--bg-soft);
}
.drop-zone:hover, .drop-zone.dragover {
  border-color: var(--accent);
  background: var(--accent-soft);
  transform: scale(1.005);
}
.drop-icon {
  width: 64px; height: 64px;
  margin: 0 auto 16px;
  border-radius: 18px;
  background: var(--accent-grad);
  display: grid; place-items: center;
  color: #fff;
  box-shadow: 0 8px 24px rgba(124,58,237,.3);
  transition: transform .3s ease;
}
.drop-zone:hover .drop-icon { transform: translateY(-4px) rotate(-3deg); }
.drop-icon svg { width: 30px; height: 30px; }
.drop-title { font-size: 17px; font-weight: 600; margin-bottom: 6px; }
.drop-sub { font-size: 13px; color: var(--text-3); }

/* 预览区 */
.preview-area { text-align: center; }
.preview-area img {
  max-width: 100%;
  max-height: 420px;
  border-radius: 12px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  animation: fadeUp .3s ease both;
}
.preview-meta {
  display: flex; justify-content: space-between;
  padding: 10px 4px;
  font-size: 13px;
  color: var(--text-3);
}
.btn-row {
  display: flex; gap: 12px; justify-content: center;
  margin-top: 16px;
}

/* 按钮 */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 11px;
  border: none;
  font-family: var(--font);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: all .2s ease;
}
.btn-primary {
  background: var(--accent-grad);
  color: #fff;
  box-shadow: 0 4px 14px rgba(124,58,237,.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 8px 24px rgba(124,58,237,.45); }
.btn-primary:active { transform: translateY(0); }
.btn-arrow { width: 16px; height: 16px; transition: transform .2s ease; }
.btn-primary:hover .btn-arrow { transform: translateX(3px); }

.btn-ghost {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text-2);
}
.btn-ghost:hover { border-color: var(--text-3); color: var(--text); }

.btn-outline {
  background: var(--card);
  border: 1px solid var(--border);
  color: var(--text-2);
  font-size: 13px;
  padding: 8px 14px;
  border-radius: 9px;
}
.btn-outline:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--accent-soft);
}

/* 识别中动画 */
.scanning {
  text-align: center;
  padding: 48px 24px;
  position: relative;
}
.scan-line {
  position: absolute;
  left: 8%; right: 8%;
  height: 2px;
  background: var(--accent-grad);
  border-radius: 2px;
  animation: scanMove 1.8s ease-in-out infinite;
  box-shadow: 0 0 20px rgba(124,58,237,.6);
  top: 30%;
}
@keyframes scanMove {
  0% { top: 20%; opacity: 0; }
  15% { opacity: 1; }
  50% { top: 75%; }
  85% { opacity: 1; }
  100% { top: 20%; opacity: 0; }
}
.scan-ring {
  width: 72px; height: 72px;
  margin: 0 auto 20px;
  position: relative;
}
.scan-ring svg { width: 100%; height: 100%; transform: rotate(-90deg); }
.ring-bg { fill: none; stroke: var(--border); stroke-width: 4; }
.ring-fg {
  fill: none;
  stroke: var(--accent);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-dasharray: 163;
  stroke-dashoffset: 163;
  animation: ringSpin 1.6s ease-in-out infinite;
}
@keyframes ringSpin {
  0% { stroke-dashoffset: 163; }
  50% { stroke-dashoffset: 40; }
  100% { stroke-dashoffset: 163; }
}
.scan-text { font-size: 16px; font-weight: 600; }
.scan-sub { font-size: 13px; color: var(--text-3); margin-top: 6px; animation: pulse 2s infinite; }

/* 结果区 */
.result-card { margin-top: 24px; animation: fadeUp .5s ease both; }
.result-head {
  display: flex; align-items: center; justify-content: space-between;
  flex-wrap: wrap; gap: 12px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--border);
}
.result-title { font-size: 18px; font-weight: 700; }
.result-tools { display: flex; gap: 8px; flex-wrap: wrap; }
.result-body { padding: 24px; }

.section-label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
  margin-bottom: 12px;
}

/* 字段确认区 */
.fields-grid { display: grid; gap: 10px; margin-bottom: 28px; }
.field-row {
  display: grid;
  grid-template-columns: 180px 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 10px 14px;
  border-radius: 10px;
  background: var(--bg-soft);
  border: 1px solid var(--border);
  transition: border-color .2s ease;
}
.field-label { font-size: 13px; font-weight: 600; color: var(--text-2); }
.field-value {
  border: none;
  background: transparent;
  font-family: var(--font);
  font-size: 14px;
  color: var(--text);
  outline: none;
  width: 100%;
  padding: 4px 0;
  border-bottom: 1px dashed transparent;
  word-break: break-word;
  overflow-wrap: anywhere;
}
.field-value:focus { border-bottom-color: var(--accent); }
.field-row.confidence-low { background: var(--warn-soft); border-color: var(--warn); }
.field-row.confidence-low .field-value { color: var(--text); font-weight: 500; }
.field-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 999px;
  white-space: nowrap;
}
.badge-high { background: var(--ok); color: #fff; opacity: .85; }
.badge-low {
  background: var(--warn);
  color: #fff;
  animation: pulse 2s infinite;
}

/* Markdown 输出 */
.md-output {
  background: var(--bg-soft);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 20px;
  font-family: 'SF Mono', 'JetBrains Mono', Consolas, monospace;
  font-size: 13.5px;
  line-height: 1.7;
  white-space: pre-wrap;
  word-break: break-word;
  max-height: 480px;
  overflow-y: auto;
  outline: none;
}
.md-output:focus { border-color: var(--accent); }
.md-output h1, .md-output h2, .md-output h3 { font-family: var(--font); margin: 14px 0 8px; line-height: 1.3; }
.md-output h1 { font-size: 17px; }
.md-output h2 { font-size: 15px; }
.md-output h3 { font-size: 14px; }
.md-output p { margin: 6px 0; }
.md-output ul, .md-output ol { padding-left: 22px; margin: 6px 0; }
.md-output table { border-collapse: collapse; margin: 10px 0; font-size: 13px; }
.md-output th, .md-output td { border: 1px solid var(--border); padding: 6px 10px; }
.md-output th { background: var(--accent-soft); font-weight: 600; }
.md-output code { background: var(--card); padding: 1px 5px; border-radius: 4px; font-size: 12px; }

/* ============ 步骤区 ============ */
.how, .faq {
  max-width: 900px;
  margin: 0 auto;
  padding: 40px 24px 60px;
}
.section-title {
  font-size: 26px;
  font-weight: 800;
  text-align: center;
  margin-bottom: 36px;
  letter-spacing: -0.01em;
}
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.step {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  text-align: center;
  transition: transform .25s ease, box-shadow .25s ease;
}
.step:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.step-num {
  width: 44px; height: 44px;
  margin: 0 auto 14px;
  border-radius: 12px;
  background: var(--accent-grad);
  color: #fff;
  font-weight: 800;
  font-size: 18px;
  display: grid; place-items: center;
  box-shadow: 0 4px 12px rgba(124,58,237,.3);
}
.step h3 { font-size: 16px; margin-bottom: 8px; }
.step p { font-size: 13.5px; color: var(--text-2); }

/* ============ FAQ ============ */
.faq-list { display: grid; gap: 12px; }
.faq-item {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 4px 20px;
  transition: border-color .2s ease;
}
.faq-item:hover { border-color: var(--accent); }
.faq-item summary {
  padding: 14px 0;
  font-weight: 600;
  font-size: 15px;
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.faq-item summary::after {
  content: '+';
  font-size: 20px;
  color: var(--text-3);
  transition: transform .25s ease;
}
.faq-item[open] summary::after { transform: rotate(45deg); }
.faq-item p { padding: 0 0 16px; font-size: 14px; color: var(--text-2); }

/* ============ Footer ============ */
.footer {
  border-top: 1px solid var(--border);
  padding: 28px 24px;
  text-align: center;
  font-size: 13px;
  color: var(--text-3);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 28px;
  left: 50%;
  transform: translateX(-50%) translateY(20px);
  background: var(--text);
  color: var(--bg);
  padding: 12px 22px;
  border-radius: 12px;
  font-size: 14px;
  font-weight: 500;
  opacity: 0;
  pointer-events: none;
  transition: all .3s ease;
  z-index: 200;
  box-shadow: var(--shadow);
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* ============ 响应式 ============ */
@media (max-width: 768px) {
  .hero { padding: 48px 20px 32px; }
  .steps { grid-template-columns: 1fr; }
  .field-row { grid-template-columns: 1fr; gap: 4px; }
  .field-badge { justify-self: start; }
  .result-head { flex-direction: column; align-items: flex-start; }
  .quota-pill { display: none; }
  .drop-zone { padding: 40px 16px; }
}
@media (max-width: 480px) {
  .btn-row { flex-direction: column; }
  .result-tools { width: 100%; }
  .result-tools .btn-outline { flex: 1; justify-content: center; }
}