* { margin: 0; padding: 0; box-sizing: border-box; }

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
    color: #1d1d1f;
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

.gradient-bg {
    position: fixed; top: 0; left: 0; width: 100%; height: 100%; z-index: -1;
    background: linear-gradient(-45deg, #e8f5f3, #e0f2f1, #e3f2fd, #e0f7fa, #f1f8e9, #e8f5e9);
    background-size: 400% 400%;
    animation: gradientShift 20s ease infinite;
}

@keyframes gradientShift {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.acrylic-header {
    position: fixed; top: 0; left: 0; right: 0; height: 60px;
    background: rgba(255, 255, 255, 0.72);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 0.5px solid rgba(0,0,0,0.1);
    z-index: 1000;
    display: flex; align-items: center; padding: 0 24px;
}

.header-content {
    width: 100%; max-width: 1200px; margin: 0 auto;
    display: flex; align-items: center; justify-content: space-between;
}

.logo-img { height: 50px; width: auto; border-radius: 8px; flex-shrink: 0; }

.header-title {
    font-size: 17px; font-weight: 450; color: #1d1d1f;
    letter-spacing: 1px; margin-right: 8px;
}

.main-content { padding: 100px 24px 100px; min-height: 100vh; }

.form-container { max-width: 600px; margin: 0 auto; }

.form-card {
    background: rgba(255,255,255,0.75);
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    border-radius: 20px; padding: 40px;
    box-shadow: 0 4px 24px rgba(0,0,0,0.06), 0 1px 2px rgba(0,0,0,0.04);
    border: 1px solid rgba(255,255,255,0.5);
}

.form-title { font-size: 28px; font-weight: 700; color: #1d1d1f; margin-bottom: 8px; letter-spacing: -0.5px; }

.form-subtitle { font-size: 15px; color: #86868b; margin-bottom: 32px; line-height: 1.7; }

.form-section { margin-bottom: 36px; }

.section-title {
    font-size: 18px; font-weight: 600; color: #1d1d1f;
    margin-bottom: 20px; padding-bottom: 8px;
    border-bottom: 1px solid rgba(0,0,0,0.08);
}

.form-group { margin-bottom: 20px; }

.form-label { display: block; font-size: 15px; font-weight: 500; color: #1d1d1f; margin-bottom: 10px; }

.form-input, .form-select {
    width: 100%; padding: 12px 16px; font-size: 15px; font-family: inherit;
    background: rgba(255,255,255,0.8); border: 1px solid rgba(0,0,0,0.12);
    border-radius: 8px; color: #1d1d1f; transition: all 0.2s ease; outline: none;
}

.form-input:focus, .form-select:focus {
    border-color: #007aff; box-shadow: 0 0 0 3px rgba(0,122,255,0.1);
}

.form-input::placeholder { color: #aeaeb2; }

.form-select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%2386868b' stroke-width='2' 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 12px center;
    cursor: pointer;
}

.radio-group { display: flex; flex-wrap: wrap; gap: 10px; }

.radio-group input[type="radio"] { display: none; }

.radio-label {
    position: relative;
    padding: 10px 16px;
    background: rgba(255,255,255,0.6);
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 8px;
    font-size: 14px;
    color: #333;
    cursor: pointer;
    transition: all 0.2s ease;
    user-select: none;
}

.radio-label:hover {
    background: rgba(255,255,255,0.9);
    border-color: rgba(0,0,0,0.15);
}

.radio-group input[type="radio"]:checked + .radio-label {
    background: #007aff;
    border-color: #007aff;
    color: white;
}

.radio-group input[type="radio"]:checked + .radio-label span {
    color: white;
}

.form-note { margin-top: 10px; font-size: 13px; color: #86868b; line-height: 1.6; padding-left: 4px; }

.next-btn {
    width: 100%; padding: 14px; font-size: 16px; font-weight: 600;
    color: white;
    background: linear-gradient(135deg, #007aff 0%, #0066dd 100%);
    border: none; border-radius: 10px; cursor: pointer;
    transition: all 0.2s ease; margin-top: 8px;
}

.next-btn:hover { transform: translateY(-1px); box-shadow: 0 4px 12px rgba(0,122,255,0.3); }

.next-btn:active { transform: translateY(0); }

.form-step {
    transition: all 0.3s ease;
    opacity: 1;
    transform: translateX(0);
}

.username-display {
    padding: 12px 16px;
    background: rgba(0,122,255,0.1);
    border: 1px solid rgba(0,122,255,0.2);
    border-radius: 8px;
    font-size: 18px;
    font-weight: 600;
    color: #007aff;
    word-break: break-all;
}

.password-input-wrapper {
    position: relative;
}

.password-input-wrapper .form-input {
    padding-right: 48px;
}

.password-toggle {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.password-toggle:hover {
    opacity: 0.7;
}

.button-group {
    display: flex;
    gap: 12px;
    margin-top: 8px;
}

.back-btn {
    flex: 1;
    padding: 14px;
    font-size: 16px;
    font-weight: 600;
    color: #333;
    background: rgba(255,255,255,0.8);
    border: 1px solid rgba(0,0,0,0.1);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.back-btn:hover {
    background: rgba(255,255,255,1);
    border-color: rgba(0,0,0,0.15);
}

.register-btn {
    flex: 2;
    padding: 14px;
    font-size: 16px;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, #007aff 0%, #0066dd 100%);
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
}

.register-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,122,255,0.3);
}

.register-btn:active {
    transform: translateY(0);
}

.success-content {
    text-align: center;
    padding: 20px 0;
}

.success-icon {
    margin-bottom: 20px;
    animation: successPulse 0.5s ease;
}

@keyframes successPulse {
    0% { transform: scale(0.8); opacity: 0; }
    50% { transform: scale(1.1); }
    100% { transform: scale(1); opacity: 1; }
}

.account-info {
    margin-top: 24px;
    padding: 20px;
    background: rgba(255,255,255,0.6);
    border-radius: 12px;
}

.info-row {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid rgba(0,0,0,0.06);
}

.info-row:last-child {
    border-bottom: none;
}

.info-label {
    font-size: 14px;
    color: #86868b;
}

.info-value {
    font-size: 14px;
    font-weight: 600;
    color: #1d1d1f;
}

.acrylic-footer {
    position: relative;
    background: rgba(255,255,255,0.72);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-top: 0.5px solid rgba(0,0,0,0.1);
    padding: 16px 24px; margin-top: auto;
}

.footer-content { max-width: 1200px; margin: 0 auto; display: flex; flex-direction: column; align-items: center; gap: 6px; }

.beian-link { display: flex; align-items: center; gap: 6px; font-size: 12px; color: #86868b; text-decoration: none; transition: color 0.2s ease; }

.beian-link:hover { color: #1d1d1f; }

.beian-icon { height: 16px; width: auto; display: inline-block; }

.beian-police { margin-bottom: 2px; }

.copyright-info { font-size: 12px; color: #86868b; margin-top: 4px; }

@media (max-width: 768px) {
    .acrylic-header { height: 56px; padding: 0 16px; }
    .header-title { font-size: 16px; }
    .main-content { padding: 80px 16px 80px; }
    .form-card { padding: 28px; border-radius: 16px; }
    .form-title { font-size: 24px; }
    .form-subtitle { font-size: 14px; }
    .section-title { font-size: 16px; }
    .footer-content { gap: 4px; }
    .radio-group { gap: 8px; }
    .radio-label { padding: 8px 12px; font-size: 13px; }
}

html { scroll-behavior: smooth; }

::selection { background: rgba(0,122,255,0.2); color: #1d1d1f; }