/* =========================================================
   在线扫描全能王 - 样式表
   主色调：深蓝 + 天蓝，简洁专业的文档处理工具风格
   ========================================================= */

:root {
  --color-primary: #1b4b8f;
  --color-primary-dark: #123566;
  --color-accent: #2da1f8;
  --color-accent-light: #e7f3ff;
  --color-bg: #f4f8fd;
  --color-surface: #ffffff;
  --color-ink: #14213d;
  --color-ink-soft: #4a5b7a;
  --color-border: #dbe6f5;
  --color-success: #2e9e6b;

  --font-display: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", "Helvetica Neue", Arial, sans-serif;
  --font-body: "PingFang SC", "Microsoft YaHei", "Segoe UI", Arial, sans-serif;

  --radius-s: 6px;
  --radius-m: 12px;
  --radius-l: 20px;
  --shadow-card: 0 6px 24px rgba(20, 33, 61, 0.08);
  --shadow-panel: 0 12px 40px rgba(27, 75, 143, 0.14);
  --max-width: 1120px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  color: var(--color-ink);
  background: var(--color-bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { font-family: var(--font-display); color: var(--color-primary-dark); margin: 0 0 .5em; }
h1 { font-size: clamp(1.9rem, 4vw, 2.8rem); line-height: 1.25; }
h2 { font-size: clamp(1.5rem, 3vw, 2rem); }
h3 { font-size: 1.1rem; }
p { margin: 0 0 1em; color: var(--color-ink-soft); }

a { color: var(--color-primary); }

img, svg { max-width: 100%; display: block; }

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

.visually-hidden {
  position: absolute;
  width: 1px; height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: #fff;
  padding: 10px 16px;
  z-index: 100;
  border-radius: 0 0 var(--radius-s) 0;
}
.skip-link:focus {
  left: 0;
}

/* focus visibility */
a:focus-visible,
button:focus-visible,
input:focus-visible,
[tabindex]:focus-visible,
summary:focus-visible {
  outline: 3px solid var(--color-accent);
  outline-offset: 2px;
}

/* =================== Header =================== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(6px);
  border-bottom: 1px solid var(--color-border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 8px;
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--color-primary-dark);
  text-decoration: none;
}
.logo-mark { color: var(--color-primary); display: inline-flex; }

.main-nav {
  display: flex;
  gap: 28px;
}
.main-nav a {
  color: var(--color-ink-soft);
  text-decoration: none;
  font-size: .95rem;
}
.main-nav a:hover { color: var(--color-primary); }

/* =================== Buttons =================== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 10px 22px;
  border-radius: var(--radius-s);
  font-size: .95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  text-decoration: none;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn-primary {
  background: var(--color-primary);
  color: #fff;
  box-shadow: 0 4px 14px rgba(27, 75, 143, 0.28);
}
.btn-primary:hover { background: var(--color-primary-dark); }
.btn-primary:disabled {
  background: #a9bcd9;
  box-shadow: none;
  cursor: not-allowed;
}
.btn-large { padding: 13px 32px; font-size: 1rem; }
.btn-ghost {
  background: transparent;
  color: var(--color-primary);
  border: 1px solid var(--color-border);
}
.btn-ghost:hover { background: var(--color-accent-light); }

/* =================== Hero / Workspace =================== */
.hero {
  padding: 56px 0 40px;
}
.hero-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 36px;
}
.eyebrow {
  color: var(--color-accent);
  font-weight: 700;
  letter-spacing: .04em;
  font-size: .9rem;
  margin-bottom: 12px;
}
.accent { color: var(--color-accent); }
.hero-desc { font-size: 1.05rem; max-width: 60ch; }

.scan-panel {
  background: var(--color-surface);
  border-radius: var(--radius-l);
  box-shadow: var(--shadow-panel);
  padding: 28px;
  border: 1px solid var(--color-border);
}

.dropzone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-m);
  padding: 36px 20px;
  text-align: center;
  cursor: pointer;
  transition: border-color .15s ease, background .15s ease;
  color: var(--color-primary);
}
.dropzone:hover,
.dropzone.is-dragover {
  border-color: var(--color-accent);
  background: var(--color-accent-light);
}
.dropzone-icon { margin: 0 auto 12px; color: var(--color-accent); }
.dropzone-title { font-weight: 600; color: var(--color-ink); margin-bottom: 4px; }
.dropzone-hint { font-size: .85rem; color: var(--color-ink-soft); margin-bottom: 18px; }

.thumb-list {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(96px, 1fr));
  gap: 12px;
  margin: 20px 0 0;
  padding: 0;
}
.thumb-list:empty { margin: 0; }
.thumb-item {
  position: relative;
  border-radius: var(--radius-s);
  overflow: hidden;
  border: 1px solid var(--color-border);
  aspect-ratio: 3 / 4;
  background: var(--color-bg);
}
.thumb-item img { width: 100%; height: 100%; object-fit: cover; }
.thumb-item .thumb-index {
  position: absolute;
  top: 4px; left: 4px;
  background: rgba(27,75,143,.85);
  color: #fff;
  font-size: .7rem;
  padding: 1px 6px;
  border-radius: 4px;
}
.thumb-item .thumb-remove {
  position: absolute;
  top: 4px; right: 4px;
  width: 20px; height: 20px;
  border-radius: 50%;
  border: none;
  background: rgba(20,33,61,.65);
  color: #fff;
  cursor: pointer;
  line-height: 1;
  font-size: .85rem;
}

.scan-actions {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  margin-top: 24px;
}
.scan-options {
  display: flex;
  flex-wrap: wrap;
  gap: 14px 20px;
}
.option-check {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: .9rem;
  color: var(--color-ink-soft);
  cursor: pointer;
}
.option-check input { accent-color: var(--color-primary); width: 16px; height: 16px; }

.scan-progress { margin-top: 24px; }
.progress-track {
  height: 8px;
  border-radius: 999px;
  background: var(--color-border);
  overflow: hidden;
}
.progress-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
  transition: width .3s ease;
}
.progress-text {
  margin: 10px 0 0;
  font-size: .9rem;
  color: var(--color-ink-soft);
}

.scan-result {
  margin-top: 24px;
  text-align: center;
  padding: 24px;
  border-radius: var(--radius-m);
  background: var(--color-accent-light);
  color: var(--color-success);
}
.scan-result p { color: var(--color-ink); font-weight: 600; }
.scan-result .btn { margin: 4px 8px; }

/* =================== Features =================== */
.features { padding: 56px 0; }
.section-sub { max-width: 60ch; }

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
  margin-top: 28px;
}
.feature-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-m);
  padding: 22px;
  box-shadow: var(--shadow-card);
}
.feature-icon {
  width: 48px; height: 48px;
  border-radius: var(--radius-s);
  background: var(--color-accent-light);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 14px;
}
.feature-card p { font-size: .92rem; margin-bottom: 0; }

/* =================== How it works =================== */
.how-it-works { padding: 56px 0; background: var(--color-surface); }
.steps {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.step {
  border-left: 3px solid var(--color-accent);
  padding-left: 18px;
}
.step-num {
  display: block;
  font-family: var(--font-display);
  font-weight: 700;
  color: var(--color-accent);
  font-size: 1.4rem;
  margin-bottom: 6px;
}
.step p { font-size: .92rem; margin-bottom: 0; }

/* =================== FAQ =================== */
.faq { padding: 56px 0; }
.faq-list {
  margin-top: 24px;
  display: flex;
  flex-direction: column;
  gap: 10px;
}
.faq-item {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-m);
  padding: 6px 20px;
}
.faq-item summary {
  cursor: pointer;
  padding: 14px 0;
  font-weight: 600;
  color: var(--color-primary-dark);
  list-style: none;
  display: flex;
  justify-content: space-between;
  gap: 12px;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
  content: "+";
  color: var(--color-accent);
  font-weight: 700;
  font-size: 1.2rem;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item p { padding-bottom: 16px; margin: 0; font-size: .92rem; }

/* =================== Help =================== */
.help { padding: 56px 0 72px; background: var(--color-surface); }
.help-grid {
  margin-top: 24px;
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}
.help-card {
  padding: 20px;
  border-radius: var(--radius-m);
  background: var(--color-bg);
  border: 1px solid var(--color-border);
}
.help-card p { font-size: .92rem; margin-bottom: 0; }

/* =================== Footer =================== */
.site-footer {
  background: var(--color-primary-dark);
  color: #cfe0f7;
  padding: 24px 0;
}
.footer-inner {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px;
  font-size: .85rem;
}
.footer-nav { display: flex; gap: 18px; }
.footer-nav a { color: #cfe0f7; text-decoration: none; }
.footer-nav a:hover { color: #fff; }

/* =================== Responsive =================== */
@media (min-width: 880px) {
  .hero-inner {
    grid-template-columns: 1fr 1fr;
    align-items: center;
  }
}

@media (max-width: 880px) {
  .main-nav { display: none; }
  .feature-grid { grid-template-columns: repeat(2, 1fr); }
  .steps { grid-template-columns: 1fr; }
  .help-grid { grid-template-columns: 1fr; }
}

@media (max-width: 560px) {
  .feature-grid { grid-template-columns: 1fr; }
  .scan-panel { padding: 20px; }
  .scan-actions { flex-direction: column; align-items: stretch; }
  .btn-large { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  * { transition: none !important; animation: none !important; }
}