:root {
    --bg1: #e6f6ff;
    --bg2: #d9f0ff;
    --accent: #37aef9;
    --accent-2: #16a4fd;
    --panel: #ffffff;
    --muted: #6b7280;
}

* {
    box-sizing: border-box
}

html,
body {
    height: 100%;
    margin: 0
}

body {
    font-family: "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", Arial, sans-serif;
    background: radial-gradient(1200px 600px at 10% 20%, rgba(55, 174, 249, 0.08), transparent),
        linear-gradient(135deg, var(--bg1), var(--bg2));
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 32px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.register-form {
    width: 100%;
    max-width: 520px;
    background: var(--panel);
    padding: 28px;
    border-radius: 14px;
    box-shadow: 0 10px 30px rgba(16, 24, 40, 0.08), 0 2px 6px rgba(16, 24, 40, 0.04);
    text-align: left;
    position: relative;
}

.register-form::before {
    content: '';
    position: absolute;
    right: -60px;
    top: -40px;
    width: 160px;
    height: 160px;
    background: linear-gradient(45deg, rgba(55, 174, 249, 0.12), rgba(22, 164, 253, 0.08));
    border-radius: 50%;
    filter: blur(24px);
    pointer-events: none;
}

.login-header,
.register-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 18px
}

.register-header .logo {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    background: linear-gradient(135deg, var(--accent), var(--accent-2));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 20px
}

.register-header h2 {
    margin: 0;
    color: var(--accent);
    font-size: 20px
}

.register-header p {
    margin: 0;
    color: var(--muted);
    font-size: 13px
}

.field {
    margin-top: 12px
}

.field label {
    display: block;
    font-size: 13px;
    color: var(--muted);
    margin-bottom: 6px
}

.field input[type="text"],
.field input[type="password"],
.field input[type="email"],
.field input[type="file"] {
    width: 100%;
    padding: 12px 14px;
    border-radius: 10px;
    border: 1px solid rgba(15, 23, 42, 0.06);
    background: linear-gradient(#fff, #fbfdff);
    font-size: 14px;
    color: #111827;
    transition: box-shadow .18s ease, transform .12s ease;
}

.field input::placeholder {
    color: #c7d5e0
}

.field input:focus {
    box-shadow: 0 6px 18px rgba(55, 174, 249, 0.14);
    transform: translateY(-1px);
    outline: none
}

.button-group {
    margin-top: 6px;
    display: flex;
    gap: 8px;
    align-items: center
}

.button-group input[type="text"] {
    flex: 1
}

.button-group button {
    padding: 8px 12px;
    border-radius: 8px;
    border: 1px solid rgba(15, 23, 42, 0.06);
    background: transparent;
    color: var(--accent);
    cursor: pointer;
    font-weight: 600
}

.button-group button:hover {
    background: rgba(55, 174, 249, 0.06)
}

/* 自定义文件选择器样式 */
.file-picker{display:flex;gap:10px;align-items:center}
.file-input{display:none}
.file-btn{padding:8px 12px;border-radius:8px;border:1px solid rgba(15,23,42,0.06);background:transparent;color:var(--accent);cursor:pointer;font-weight:600}
.file-btn:hover{background:rgba(55,174,249,0.06)}
.file-name{font-size:13px;color:var(--muted);max-width:240px;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}

/* 样式应用到 input 旁边的内联按钮（例如随机用户名） */
.field>div button,
#random_username {
    padding: 8px 12px;
    border-radius: 8px;
    border: 1px solid rgba(15, 23, 42, 0.06);
    background: transparent;
    color: var(--accent);
    cursor: pointer;
    font-weight: 600;
    width: 120px;
}

.field>div button:hover,
#random_username:hover {
    background: rgba(55, 174, 249, 0.06)
}

.shield-verify {
    margin-top: 12px
}

.submit-row {
    margin-top: 18px
}

.submit-row input[type="submit"] {
    width: 100%;
    padding: 12px 14px;
    border-radius: 10px;
    border: none;
    background: linear-gradient(90deg, var(--accent), var(--accent-2));
    color: #fff;
    font-weight: 600;
    font-size: 15px;
    cursor: pointer;
    box-shadow: 0 8px 20px rgba(22, 164, 253, 0.18);
    transition: transform .12s ease, box-shadow .12s ease, opacity .12s ease;
}

.submit-row input[type="submit"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 28px rgba(22, 164, 253, 0.18)
}

.action {
    display: flex;
    gap: 10px;
    justify-content: center;
    margin-top: 14px
}

.action button {
    background: transparent;
    border: 1px solid rgba(15, 23, 42, 0.06);
    padding: 8px 14px;
    border-radius: 8px;
    cursor: pointer;
    color: var(--accent);
    font-weight: 600
}

.action button:hover {
    background: rgba(55, 174, 249, 0.06)
}

@media (max-width:640px) {
    .register-form {
        padding: 18px;
        border-radius: 12px
    }
}

/* accessibility */
input,
button {
    outline: none
}

button:focus,
input:focus {
    box-shadow: 0 8px 20px rgba(55, 174, 249, 0.12)
}