:root {
  --bg: #f5f6f8;
  --panel: #ffffff;
  --ink: #1a1f2b;
  --ink-soft: #4a5265;
  --ink-dim: #8a92a4;
  --line: #e4e7ee;
  --accent: #3a5bd9;
  --accent-soft: #eaeffc;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 28, 48, 0.04), 0 8px 24px rgba(20, 28, 48, 0.06);
  --c-problem: #d9534f;
  --c-method: #3a5bd9;
  --c-finding: #1f9d6b;
  --c-limit: #d68a1e;
  --c-scene: #7a4fd0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans SC",
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
}

* { box-sizing: border-box; }

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

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* Topbar */
.topbar {
  background: rgba(255, 255, 255, 0.86);
  backdrop-filter: saturate(160%) blur(8px);
  border-bottom: 1px solid var(--line);
  position: sticky; top: 0; z-index: 10;
}
.topbar-inner { display: flex; align-items: center; justify-content: space-between; height: 58px; }
.brand { display: flex; align-items: center; gap: 9px; font-weight: 700; font-size: 17px; }
.brand-mark { color: var(--accent); font-size: 20px; }
.topnav { display: flex; align-items: center; gap: 18px; font-size: 14px; }
.topnav a { color: var(--ink-soft); text-decoration: none; }
.topnav a:hover { color: var(--accent); }
.badge-local {
  background: var(--accent-soft); color: var(--accent);
  font-size: 12px; font-weight: 600; padding: 4px 10px; border-radius: 999px;
}

/* Hero */
.hero { padding: 44px 20px 22px; text-align: center; }
.hero h1 { font-size: 34px; line-height: 1.25; margin: 0 0 14px; letter-spacing: -0.01em; }
.hero-sub { color: var(--ink-soft); font-size: 16px; max-width: 640px; margin: 0 auto; }
.mobile-break { display: none; }

/* Workbench */
.workbench { display: grid; grid-template-columns: 1fr; gap: 20px; padding-bottom: 20px; }
.panel {
  background: var(--panel); border: 1px solid var(--line);
  border-radius: var(--radius); box-shadow: var(--shadow); padding: 20px;
}
.panel-head { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 10px; margin-bottom: 14px; }
.panel-head h2 { font-size: 16px; margin: 0; }

.samples, .out-actions { display: flex; align-items: center; gap: 8px; flex-wrap: wrap; }
.samples-label { font-size: 13px; color: var(--ink-dim); }
.chip {
  border: 1px solid var(--line); background: #fff; color: var(--ink-soft);
  font-size: 13px; padding: 6px 12px; border-radius: 999px; cursor: pointer;
  transition: all 0.15s;
}
.chip:hover { border-color: var(--accent); color: var(--accent); }
.chip.ghost { color: var(--ink-dim); }

textarea {
  width: 100%; min-height: 240px; resize: vertical;
  border: 1px solid var(--line); border-radius: 10px; padding: 14px;
  font-size: 14.5px; line-height: 1.7; color: var(--ink);
  font-family: inherit; background: #fcfcfd;
}
textarea:focus { outline: none; border-color: var(--accent); background: #fff; }

.input-foot { display: flex; align-items: center; justify-content: space-between; margin-top: 14px; }
.stats { font-size: 13px; color: var(--ink-dim); }
.primary {
  background: var(--accent); color: #fff; border: none; font-weight: 600;
  font-size: 15px; padding: 11px 22px; border-radius: 10px; cursor: pointer;
  box-shadow: 0 4px 12px rgba(58, 91, 217, 0.28); transition: transform 0.1s, box-shadow 0.15s;
}
.primary:hover { transform: translateY(-1px); box-shadow: 0 6px 16px rgba(58, 91, 217, 0.34); }
.primary:active { transform: translateY(0); }

/* Summary strip */
.summary-strip {
  display: flex; flex-wrap: wrap; gap: 10px; margin-bottom: 18px;
  padding: 14px; background: #fafbfd; border: 1px solid var(--line); border-radius: 10px;
}
.summary-item { font-size: 13px; color: var(--ink-soft); }
.summary-item b { color: var(--ink); }
.summary-tldr {
  width: 100%; font-size: 15px; color: var(--ink); padding-bottom: 10px;
  margin-bottom: 4px; border-bottom: 1px dashed var(--line);
}
.summary-tldr .lbl { color: var(--accent); font-weight: 700; margin-right: 6px; }

/* Cards */
.cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 14px; }
.card {
  border: 1px solid var(--line); border-radius: 12px; padding: 15px 16px;
  border-top: 3px solid var(--cc, var(--accent)); background: #fff;
}
.card-head { display: flex; align-items: baseline; justify-content: space-between; margin-bottom: 8px; }
.card-title { font-size: 15px; font-weight: 700; color: var(--cc); }
.card-count { font-size: 12px; color: var(--ink-dim); }
.card ul { margin: 0; padding-left: 18px; }
.card li { font-size: 13.5px; color: var(--ink-soft); margin-bottom: 7px; }
.card .empty { font-size: 13px; color: var(--ink-dim); font-style: italic; padding-left: 2px; }

.card-problem { --cc: var(--c-problem); }
.card-method { --cc: var(--c-method); }
.card-finding { --cc: var(--c-finding); }
.card-limit { --cc: var(--c-limit); }
.card-scene { --cc: var(--c-scene); }

/* Extras */
.extras { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 1fr)); gap: 16px; margin-top: 22px; }
.extra-block h3 { font-size: 14px; margin: 0 0 8px; display: flex; align-items: baseline; gap: 8px; }
.extra-block .hint { font-size: 12px; color: var(--ink-dim); font-weight: 400; }
.extra-block ul { margin: 0; padding-left: 18px; }
.extra-block li { font-size: 13.5px; color: var(--ink-soft); margin-bottom: 7px; }

.disclaimer {
  margin-top: 22px; padding: 12px 14px; font-size: 12.5px; color: var(--ink-dim);
  background: #fafbfd; border: 1px solid var(--line); border-radius: 10px;
}

/* Explain sections */
.explain { padding: 26px 20px; }
.explain h2 { font-size: 22px; margin: 0 0 16px; }
.steps { margin: 0; padding-left: 20px; color: var(--ink-soft); font-size: 15px; }
.steps li { margin-bottom: 8px; }
.steps strong { color: var(--ink); }

.why-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 16px; }
.why-card { background: var(--panel); border: 1px solid var(--line); border-radius: 12px; padding: 18px; box-shadow: var(--shadow); }
.why-card h3 { font-size: 16px; margin: 0 0 8px; }
.why-card p { font-size: 14px; color: var(--ink-soft); margin: 0; }

/* Footer */
.footer { border-top: 1px solid var(--line); padding: 22px 0; margin-top: 20px; }
.footer .wrap { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; font-size: 13px; color: var(--ink-soft); }
.footer .dim { color: var(--ink-dim); }

/* Toast */
.toast {
  position: fixed; bottom: 26px; left: 50%; transform: translateX(-50%) translateY(20px);
  background: var(--ink); color: #fff; padding: 10px 18px; border-radius: 999px;
  font-size: 14px; opacity: 0; pointer-events: none; transition: all 0.25s; z-index: 50;
}
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

@media (min-width: 860px) {
  .workbench { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
  .hero h1 { font-size: 26px; }
  .mobile-break { display: inline; }
  .topnav a { display: none; }
  .hero { padding-top: 30px; }
  .input-foot { flex-direction: column; gap: 12px; align-items: stretch; }
  .primary { width: 100%; }
}