:root{--bg:#f5f7fb;--paper:#fff;--ink:#172033;--muted:#778196;--line:#dfe5ef;--blue:#356ae6;--blue-soft:#eaf0ff;--green:#168b57;--red:#c84949;--shadow:0 12px 35px rgba(37,55,88,.08)}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:16px/1.7 -apple-system,BlinkMacSystemFont,"PingFang SC","Microsoft YaHei",sans-serif}.app{max-width:860px;margin:auto;padding:24px 18px 110px}header{display:flex;align-items:center;justify-content:space-between;gap:16px;margin-bottom:18px}header h1{font-size:24px;letter-spacing:.02em;margin:0}header p{margin:2px 0 0;color:var(--muted);font-size:13px}header button{background:var(--paper);color:var(--muted)}.card{background:var(--paper);border:1px solid var(--line);border-radius:18px;box-shadow:var(--shadow)}.login{max-width:400px;margin:14vh auto;padding:30px}.login h1{margin:0 0 4px}.login p{color:var(--muted);margin-top:0}.login label{display:grid;gap:6px;margin:14px 0;color:var(--muted);font-size:13px}.login input{margin-top:0}.stats{display:grid;grid-template-columns:repeat(4,1fr);gap:10px;margin-bottom:16px}.stats span{background:var(--paper);border:1px solid var(--line);border-radius:13px;padding:10px 12px;color:var(--muted);font-size:13px}.stats b{display:block;color:var(--ink);font-size:21px;line-height:1.2}.subjects{display:flex;overflow:auto;gap:7px;margin-bottom:12px;padding-bottom:2px}.subjects button{white-space:nowrap;background:var(--paper);color:#53617a}.subjects button:hover,.subjects button:focus{color:var(--blue);border-color:#9db6fa}.filters{display:grid;grid-template-columns:1fr 160px auto;gap:8px;margin-bottom:18px}input,select,button{font:inherit}input,select{width:100%;padding:11px 13px;border:1px solid var(--line);border-radius:11px;background:var(--paper);color:var(--ink);outline:none}input:focus,select:focus{border-color:var(--blue);box-shadow:0 0 0 3px var(--blue-soft)}button{border:1px solid var(--line);border-radius:11px;background:#f8faff;color:var(--ink);padding:10px 15px;cursor:pointer;transition:.18s ease}button:hover{transform:translateY(-1px);box-shadow:0 5px 12px rgba(37,55,88,.08)}button.primary{background:var(--blue);border-color:var(--blue);color:#fff;font-weight:700}.question{padding:26px 28px;min-height:410px}.meta{display:flex;justify-content:space-between;color:var(--muted);font-size:13px;border-bottom:1px solid var(--line);padding-bottom:12px;margin-bottom:22px}.question h2{font-size:23px;line-height:1.75;margin:0 0 24px;font-weight:700}.options{display:grid;gap:10px}.options button{text-align:left;background:#fbfcff;padding:14px 16px}.options button.selected{border-color:var(--blue);background:var(--blue-soft);color:var(--blue)}.options button.correct{border-color:var(--green);background:#eaf8f1;color:var(--green)}.options button.wrong{border-color:var(--red);background:#fff0f0;color:var(--red)}.result{margin-top:20px;padding:13px 15px;border-radius:11px;font-weight:700}.result p{font-weight:400;margin:7px 0 0;white-space:pre-wrap}.result.good{background:#eaf8f1;color:var(--green)}.result.bad{background:#fff0f0;color:var(--red)}.pager{display:flex;justify-content:space-between;margin-top:14px}.pager button{min-width:96px}.empty{text-align:center;padding:55px;color:var(--muted)}.error{color:var(--red);min-height:24px} @media(max-width:640px){.app{padding:14px 10px 80px}header h1{font-size:20px}.stats{gap:6px}.stats span{padding:8px;font-size:12px}.stats b{font-size:18px}.filters{grid-template-columns:1fr 1fr}.filters input{grid-column:1/-1}.filters .primary{grid-column:1/-1}.question{padding:18px 16px;min-height:440px}.question h2{font-size:19px;line-height:1.65}.subjects{margin-left:-2px;margin-right:-2px}.pager button{min-width:88px}}