:root{color-scheme:dark;--bg:#0A0A0B;--surface:#141416;--text:#F4F4F5;--strong:#FFFFFF;--secondary:#A1A1AA;--border:#3F3F46;--border-strong:#6B6B74;--primary:#D9DCE1;--primary-hover:#E6E8EC;--primary-text:#0A0A0B;--hover:#232326;--focus:#E3E6EA;--danger:#F2A19C;--danger-bg:#2A1716;--danger-border:#6B2F2C;--note-bg:#1C1C1F;--sans:system-ui,-apple-system,"PingFang TC","Noto Sans TC","Microsoft JhengHei",sans-serif}
@media (prefers-color-scheme:light){:root{color-scheme:light;--bg:#F4F4F5;--surface:#FFFFFF;--text:#18181B;--strong:#0A0A0B;--secondary:#52525B;--border:#C9CDD3;--border-strong:#71717A;--primary:#18181B;--primary-hover:#2E2E33;--primary-text:#FFFFFF;--hover:#ECECEE;--focus:#18181B;--danger:#9B1C14;--danger-bg:#FDECEA;--danger-border:#E5A8A2;--note-bg:#F4F4F5}}
*{box-sizing:border-box}html,body{margin:0;overflow-x:clip}
body{background:var(--bg);color:var(--text);font-family:var(--sans);font-size:16px;line-height:1.6;min-height:100dvh;-webkit-text-size-adjust:100%}
main{max-width:440px;margin:0 auto;padding:max(24px,env(safe-area-inset-top)) max(16px,env(safe-area-inset-right)) max(32px,env(safe-area-inset-bottom)) max(16px,env(safe-area-inset-left))}
.brand{margin:16px 0 20px;font-weight:600;color:var(--strong)}
.card{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:24px}
h1{font-size:26px;line-height:1.3;margin:0 0 4px;color:var(--strong);font-weight:650;overflow-wrap:break-word;min-width:0}h1:focus{outline:none}
h2{font-size:18px;margin:0 0 8px;color:var(--strong)}
.lead{margin:0 0 20px;color:var(--secondary)}
.field{margin:0 0 16px}label{display:block;font-size:15px;margin:0 0 6px;color:var(--text)}
input[type=text],input[type=email],input[type=tel],input[type=password]{width:100%;min-height:48px;padding:10px 12px;font:inherit;font-size:16px;color:var(--strong);background:var(--bg);border:1px solid var(--border-strong);border-radius:8px}
input[aria-invalid=true]{border-color:var(--danger)}
.pw{display:flex;gap:8px}.pw input{flex:1;min-width:0}
.hint{margin:6px 0 0;font-size:14px;color:var(--secondary)}
.check{display:flex;gap:10px;align-items:center;min-height:44px;margin:0 0 16px;font-size:15px}.check input{width:22px;height:22px;margin:0;flex:none;accent-color:var(--primary)}
.btn{display:inline-flex;align-items:center;justify-content:center;width:100%;min-height:48px;padding:10px 16px;margin:0 0 12px;font:inherit;font-weight:600;color:var(--text);background:transparent;border:1px solid var(--border-strong);border-radius:8px;cursor:pointer;text-decoration:none;transition:background-color .15s,border-color .15s}
.btn:hover{background:var(--hover)}.btn.primary{background:var(--primary);color:var(--primary-text);border-color:var(--primary)}.btn.primary:hover{background:var(--primary-hover)}
.ghost{flex:none;min-width:64px;min-height:48px;font:inherit;font-size:15px;color:var(--text);background:transparent;border:1px solid var(--border-strong);border-radius:8px;cursor:pointer}.ghost:hover{background:var(--hover)}
button:disabled,.btn[aria-disabled=true]{opacity:.55;cursor:not-allowed}
a{color:var(--strong);text-underline-offset:3px}
:focus-visible{outline:2px solid var(--focus);outline-offset:2px}
.links{display:flex;flex-wrap:wrap;gap:0 16px;justify-content:space-between;align-items:center;margin:8px 0 0;font-size:15px}.links a{display:inline-flex;align-items:center;min-height:44px;padding:0 4px}.links .btn{margin:0}
.row{display:flex;flex-wrap:wrap;gap:8px}.row .btn{flex:1 1 140px;margin:0}
.note{background:var(--note-bg);border:1px solid var(--border);border-radius:8px;padding:12px;margin:0 0 20px}.note p{margin:0 0 12px}
.msg{margin:16px 0 0;padding:10px 12px;border-radius:8px;border:1px solid var(--border);background:var(--note-bg)}.msg.error{color:var(--danger);background:var(--danger-bg);border-color:var(--danger-border)}
[hidden]{display:none!important}
@media (max-width:360px){.card{padding:16px}h1{font-size:23px}}
@media (prefers-reduced-motion:reduce){.btn{transition:none}}