:root{
  --theme:#c8102e;
  --theme-d:#9c0c22;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  font-family:-apple-system,BlinkMacSystemFont,"Microsoft YaHei","PingFang SC",sans-serif;
  color:#222;background:#f4f5f7;
  -webkit-tap-highlight-color:transparent;
  min-height:100vh;
}
.wrap{max-width:520px;margin:0 auto;min-height:100vh;display:flex;flex-direction:column;position:relative}
.page-bg{position:fixed;inset:0;background-size:cover;background-position:center;z-index:-1}
.page-bg::after{content:"";position:absolute;inset:0;background:rgba(255,255,255,.55)}

/* 顶部 */
.topbar{background:linear-gradient(135deg,var(--theme),var(--theme-d));color:#fff;padding:18px 18px;text-align:center;box-shadow:0 2px 8px rgba(0,0,0,.12)}
.topbar .logo{height:40px;margin-bottom:8px}
.topbar h1{margin:0;font-size:20px;font-weight:700;letter-spacing:1px}
.topbar .sub{margin-top:4px;font-size:13px;opacity:.9}

.content{flex:1;padding:18px}
.card{background:#fff;border-radius:14px;box-shadow:0 4px 18px rgba(0,0,0,.06);padding:22px 20px;margin-bottom:16px}

.banner{width:100%;border-radius:14px;margin-bottom:16px;display:block}

.rule{font-size:14px;line-height:1.9;color:#555;white-space:pre-line}
.rule h3{color:var(--theme);font-size:16px;margin:0 0 8px}

label.fld{display:block;font-size:14px;color:#444;margin:16px 0 6px;font-weight:600}
input.fld{width:100%;padding:13px 14px;border:1.5px solid #e3e3e3;border-radius:10px;font-size:16px;outline:none}
input.fld:focus{border-color:var(--theme)}

.btn{display:block;width:100%;padding:15px;background:var(--theme);color:#fff;border:0;border-radius:10px;font-size:17px;font-weight:600;cursor:pointer;margin-top:22px}
.btn:active{background:var(--theme-d)}
.btn[disabled]{opacity:.5}

.footer{text-align:center;color:#aaa;font-size:12px;padding:16px}
.msg{color:var(--theme);font-size:13px;margin-top:10px;min-height:18px;text-align:center}

/* 答题页 */
.center-box{flex:1;display:flex;flex-direction:column;align-items:center;justify-content:center;text-align:center;padding:30px}
.spinner{width:46px;height:46px;border:4px solid #eee;border-top-color:var(--theme);border-radius:50%;animation:spin 1s linear infinite;margin-bottom:18px}
@keyframes spin{to{transform:rotate(360deg)}}
.waiting-text{font-size:16px;color:#666;line-height:1.8;white-space:pre-line}
.hello{font-size:14px;color:#999;margin-top:14px}

.q-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:6px}
.q-no{font-size:14px;color:#999}
.q-score{font-size:13px;color:var(--theme);font-weight:600}
.timer{position:relative;height:8px;background:#eee;border-radius:4px;overflow:hidden;margin:12px 0 4px}
.timer .bar{position:absolute;left:0;top:0;bottom:0;background:var(--theme);transition:width .9s linear}
.timer-num{text-align:center;font-size:34px;font-weight:800;color:var(--theme);margin:6px 0 14px}
.q-type{display:inline-block;font-size:12px;color:#fff;background:var(--theme);border-radius:20px;padding:2px 12px;margin-bottom:10px}
.q-title{font-size:18px;line-height:1.7;font-weight:600;color:#222;margin-bottom:18px}

.opt{display:flex;align-items:center;padding:14px 16px;border:1.5px solid #e6e6e6;border-radius:12px;margin-bottom:12px;font-size:16px;cursor:pointer;background:#fff;transition:.15s}
.opt .k{width:28px;height:28px;flex:none;border-radius:50%;background:#f0f0f0;color:#666;display:flex;align-items:center;justify-content:center;font-weight:700;margin-right:12px}
.opt.sel{border-color:var(--theme);background:#fff5f6}
.opt.sel .k{background:var(--theme);color:#fff}
.opt.correct{border-color:#2e7d32;background:#edf7ee}
.opt.correct .k{background:#2e7d32;color:#fff}
.opt.wrong{border-color:#c62828;background:#fdecec}
.opt.wrong .k{background:#c62828;color:#fff}
.opt.disabled{pointer-events:none;opacity:.95}

.judge-row{display:flex;gap:14px}
.judge-row .opt{flex:1;justify-content:center;font-size:18px;font-weight:600}

input.fill{width:100%;padding:14px;border:1.5px solid #e6e6e6;border-radius:12px;font-size:17px;text-align:center}

.result-banner{text-align:center;padding:18px;border-radius:12px;font-size:18px;font-weight:700;margin-top:8px}
.result-banner.ok{background:#edf7ee;color:#2e7d32}
.result-banner.no{background:#fdecec;color:#c62828}
.result-sub{text-align:center;color:#888;font-size:14px;margin-top:10px}
.answered-tip{text-align:center;color:#888;font-size:15px;padding:24px 0}
.big-score{font-size:40px;font-weight:800;color:var(--theme);margin:6px 0}