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

:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --bg-light: #f8fafc;
    --bg-white: #ffffff;
    --text-dark: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --error-color: #ef4444;
    --success-color: #22c55e;
}

body {
    font-family: 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.register-container {
    width: 100%;
    max-width: 420px;
}

.register-box {
    background: var(--bg-white);
    border-radius: 16px;
    padding: 2.5rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
    animation: slideUp 0.5s ease;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.register-header {
    text-align: center;
    margin-bottom: 2rem;
}

.register-header h1 {
    font-size: 1.75rem;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.register-header p {
    color: var(--text-secondary);
}

.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.form-group input {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    transition: all 0.3s ease;
    font-family: inherit;
}

.form-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.form-options {
    margin-bottom: 1.5rem;
}

.form-group label .optional {
    font-size: 0.75rem;
    font-weight: 400;
    color: var(--text-secondary);
}

.form-group textarea {
    width: 100%;
    padding: 0.875rem 1rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    transition: all 0.3s ease;
}

.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.agree-terms {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

.agree-terms input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary-color);
}

.agree-terms a {
    color: var(--primary-color);
    text-decoration: none;
}

.agree-terms a:hover {
    text-decoration: underline;
}

.message {
    padding: 0.875rem 1rem;
    border-radius: 10px;
    margin-bottom: 1rem;
    font-size: 0.875rem;
    text-align: center;
    animation: shake 0.5s ease;
}

.message.error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error-color);
    border: 1px solid rgba(239, 68, 68, 0.3);
}

.message.success {
    background: rgba(34, 197, 94, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(34, 197, 94, 0.3);
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    20%, 60% { transform: translateX(-5px); }
    40%, 80% { transform: translateX(5px); }
}

.btn-register-submit {
    width: 100%;
    padding: 1rem;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    font-family: inherit;
}

.btn-register-submit:hover:not(:disabled) {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 14px rgba(37, 99, 235, 0.4);
}

.btn-register-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.register-footer {
    text-align: center;
    margin-top: 1.5rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.register-footer p {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: 0.5rem;
}

.register-footer a {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
}

.register-footer a:hover {
    text-decoration: underline;
}

@media (max-width: 480px) {
    body {
        padding: 1rem;
    }

    .register-box {
        padding: 2rem 1.5rem;
    }
}