/* feedback.css — extracted verbatim from the original feedback.html <style>.
   Visual design is preserved 1:1; do not restyle without a design review. */
:root{
  --bg:#eef3f0; --surface:#ffffff; --surface-2:#f5f8f6;
  --ink:#152019; --muted:#57665d; --faint:#7f8e84;
  --line:#dde6e0; --line-strong:#cbd6cf;
  --accent:#0e9d68; --accent-ink:#0a6f4a; --accent-soft:#dcefe6;
  --shadow:0 1px 2px rgba(16,40,30,.04), 0 12px 32px -12px rgba(16,40,30,.18);
  --radius:16px;
  --display:'Sora','PingFang SC','Microsoft YaHei',system-ui,sans-serif;
  --body:'IBM Plex Sans','PingFang SC','Microsoft YaHei',system-ui,sans-serif;
  --mono:'IBM Plex Mono',ui-monospace,'Cascadia Code',monospace;
}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]){
    --bg:#0d1512; --surface:#141e1a; --surface-2:#1a2620;
    --ink:#e9efeb; --muted:#a0b1a8; --faint:#78897f;
    --line:#233129; --line-strong:#2c3b32;
    --accent:#2fd08a; --accent-ink:#5be3a6; --accent-soft:#12271e;
    --shadow:0 1px 2px rgba(0,0,0,.4), 0 16px 40px -14px rgba(0,0,0,.6);
  }
}
*{box-sizing:border-box}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--body);
  line-height:1.6;-webkit-font-smoothing:antialiased}
.wrap{max-width:720px;margin:0 auto;padding-inline:24px}
a{color:inherit}
header{position:sticky;top:0;z-index:20;
  background:color-mix(in srgb,var(--bg) 82%,transparent);
  backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
.nav{display:flex;align-items:center;justify-content:space-between;padding-block:13px;gap:16px}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--display);
  font-weight:600;font-size:16px;text-decoration:none}
.dot{width:11px;height:11px;border-radius:50%;background:var(--accent);
  box-shadow:0 0 0 3px var(--accent-soft);flex:none}
.brand .en{color:var(--faint);font-weight:500;font-size:13px;font-family:var(--mono)}
.nav-meta{display:flex;gap:12px;align-items:center}
.lang{position:relative;display:flex;align-items:center}
.lang select{appearance:none;-webkit-appearance:none;font-family:var(--body);
  font-size:13.5px;color:var(--ink);background:var(--surface);
  border:1px solid var(--line-strong);border-radius:9px;
  padding:8px 28px 8px 12px;cursor:pointer}
h1{font-family:var(--display);font-size:clamp(28px,5vw,36px);font-weight:700;
  letter-spacing:-.02em;margin:40px 0 10px}
.lede{color:var(--muted);margin:0 0 28px}
form{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);
  padding:28px;box-shadow:var(--shadow);display:flex;flex-direction:column;gap:16px}
label{font-size:13.5px;font-weight:600;display:flex;flex-direction:column;gap:8px}
.hint{font-weight:500;color:var(--faint);font-size:12.5px}
input,textarea{font:inherit;color:var(--ink);background:var(--surface-2);
  border:1px solid var(--line-strong);border-radius:10px;padding:11px 13px;width:100%}
input:focus,textarea:focus{outline:2px solid var(--accent);outline-offset:1px}
textarea{min-height:160px;resize:vertical}
.hp{position:absolute;left:-9999px;height:0;overflow:hidden}
.row{display:grid;grid-template-columns:1fr 1fr;gap:14px}
@media (max-width:560px){.row{grid-template-columns:1fr}}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--display);font-weight:600;font-size:15px;padding:12px 20px;
  border-radius:11px;border:0;cursor:pointer;background:var(--accent);color:#04150e}
.btn:disabled{opacity:.6;cursor:not-allowed}
.status{min-height:1.4em;font-size:14px}
.status.ok{color:var(--accent-ink)}
.status.err{color:#b42318}
footer{padding:36px 0;color:var(--faint);font-family:var(--mono);font-size:13px}