*, *::before, *::after { box-sizing: border-box; }
:root { 
    --p: #0071e3; --bg-color: #f5f5f7; --card-bg: rgba(255, 255, 255, 0.85);
    --text-main: #1d1d1f; --text-sub: #86868b; --border: rgba(0, 0, 0, 0.08); 
    --input-bg: rgba(255, 255, 255, 0.8); --danger: #ff3b30;
}
body { 
    margin: 0; padding: 0; font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", sans-serif; 
    background: var(--bg-color); 
    background-image: radial-gradient(at 0% 0%, hsla(253,16%,7%,1) 0, transparent 50%), radial-gradient(at 50% 0%, hsla(225,39%,30%,1) 0, transparent 50%), radial-gradient(at 100% 0%, hsla(339,49%,30%,1) 0, transparent 50%);
    background-attachment: fixed; display: flex; justify-content: center; align-items: center; 
    min-height: 100vh; color: var(--text-main); -webkit-font-smoothing: antialiased;
}
.auth-container { 
    background: var(--card-bg); backdrop-filter: blur(40px); -webkit-backdrop-filter: blur(40px);
    width: 100%; max-width: 400px; padding: 40px; border-radius: 28px; 
    box-shadow: 0 20px 40px rgba(0,0,0,0.1), 0 0 0 1px rgba(255,255,255,0.5) inset; 
    animation: springUp 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}
@keyframes springUp { 0% { opacity: 0; transform: translateY(40px) scale(0.95); } 100% { opacity: 1; transform: translateY(0) scale(1); } }
.logo { text-align: center; font-size: 28px; font-weight: 800; margin-bottom: 6px; letter-spacing: -0.5px; }
.logo span { color: var(--p); font-weight: 700;}
.desc { text-align: center; font-size: 14px; color: var(--text-sub); margin-bottom: 32px; font-weight: 500;}
.tabs { display: flex; background: rgba(0,0,0,0.05); padding: 4px; border-radius: 12px; margin-bottom: 28px; }
.tab { flex: 1; text-align: center; padding: 10px 0; font-size: 14px; font-weight: 600; color: var(--text-sub); cursor: pointer; transition: 0.3s; border-radius: 8px; }
.tab.active { color: var(--text-main); background: #ffffff; box-shadow: 0 2px 8px rgba(0,0,0,0.06); }
.form-box { display: none; animation: fadeBlur 0.4s cubic-bezier(0.16, 1, 0.3, 1); }
.form-box.active { display: block; }
@keyframes fadeBlur { from { opacity: 0; filter: blur(4px); transform: translateY(10px); } to { opacity: 1; filter: blur(0); transform: translateY(0); } }
.input-group { margin-bottom: 16px; position: relative; transition: all 0.3s ease; opacity: 1; max-height: 100px; overflow: hidden; }
.input-group.collapsed { max-height: 0; opacity: 0; margin-bottom: 0; pointer-events: none; }
.input-css { width: 100%; padding: 16px 18px; border: 1px solid var(--border); border-radius: 14px; outline: none; font-size: 15px; box-sizing: border-box; transition: 0.2s; background: var(--input-bg); color: var(--text-main); font-weight: 500;}
.input-css::placeholder { color: #a1a1a6; font-weight: 400;}
.input-css:focus { border-color: var(--p); background: #ffffff; box-shadow: 0 0 0 4px rgba(0, 113, 227, 0.15); }
.input-css.select { appearance: none; -webkit-appearance: none; background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%2386868b' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e"); background-repeat: no-repeat; background-position: right 14px center; background-size: 14px; padding-right: 36px; cursor: pointer; text-overflow: ellipsis; white-space: nowrap; }
.flex-row { display: flex; gap: 10px; align-items: center; width: 100%; }
.flex-row > input.input-css { flex: 1; min-width: 0; } 
.flex-row > img, .flex-row > button { flex-shrink: 0; } 
.email-row { gap: 6px; } .email-row input { flex: 1.3; } .email-row select { flex: 1; padding-left: 10px; padding-right: 28px; background-position: right 8px center;}
.at-symbol { font-size: 16px; font-weight: 700; color: var(--text-sub); }
.btn { width: 100%; padding: 16px; background: var(--text-main); color: #fff; border: none; border-radius: 14px; font-size: 15px; font-weight: 600; cursor: pointer; transition: 0.3s; display: flex; justify-content: center; align-items: center; gap: 8px; }
.btn:hover { background: #000; transform: scale(0.98);}
.btn.primary { background: var(--p); } .btn.primary:hover { background: #0077ED; box-shadow: 0 4px 15px rgba(0, 113, 227, 0.3); }
.btn-outline { background: #fff; color: var(--text-main); border: 1px solid var(--border); font-weight: 600; box-shadow: 0 2px 5px rgba(0,0,0,0.02);} .btn-outline:hover { background: #f5f5f7; transform: scale(0.98);}
.btn:disabled { opacity: 0.5; cursor: not-allowed; transform: none; box-shadow: none;}
.link-text { text-align: center; font-size: 13px; font-weight: 500; color: var(--p); cursor: pointer; margin-top: 20px; transition: 0.2s; }
.link-text:hover { text-decoration: underline; }
.toast { position: fixed; top: 40px; left: 50%; transform: translateX(-50%) translateY(-20px); background: rgba(29, 29, 31, 0.85); backdrop-filter: blur(20px); color: #fff; padding: 12px 24px; border-radius: 30px; font-size: 14px; font-weight: 500; opacity: 0; transition: 0.5s; pointer-events: none; z-index: 9999; box-shadow: 0 10px 30px rgba(0,0,0,0.2); white-space: nowrap; }
.toast.show { opacity: 1; transform: translateX(-50%) translateY(0); }

/* 手机端响应式 */
@media (max-width: 480px) {
    body { align-items: center; padding: 16px; }
    .auth-container { border-radius: 28px; padding: 32px 20px; background: rgba(255, 255, 255, 0.95); max-height: 85vh; overflow-y: auto; -webkit-overflow-scrolling: touch; }
    .auth-container::-webkit-scrollbar { display: none; }
    .input-css { padding: 15px 14px; background: #f0f0f5; border: 1px solid transparent; font-size: 14px;}
    .input-css:focus { background: #fff; border: 1px solid var(--p); }
    .logo { font-size: 24px; } .desc { margin-bottom: 20px; font-size: 13px;}
    #img_l_captcha, #img_r_captcha, #img_f_captcha { height: 50px !important; width: 100px !important; }
    .btn-outline { height: 50px !important; width: 100px !important; font-size: 12px !important; padding: 0 !important; }
}