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

body {
    font-family: 'Inter', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    background: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    min-height: 100vh;
    color: #f1f5f9;
}

.navbar {
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding: 0 5%;
    height: 70px;
    display: flex;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-img {
    width: 40px;
    height: 40px;
    background: #3b82f6;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    color: white;
}

.logo h2 {
    font-size: 1.5rem;
    font-weight: 600;
    background: linear-gradient(135deg, #fff, #94a3b8);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.main-content {
    display: flex;
    flex-wrap: wrap;
    max-width: 1400px;
    margin: 40px auto;
    padding: 0 5%;
    gap: 48px;
    align-items: flex-start; /* 顶部对齐 */
}

.welcome-section {
    flex: 1.2;
    min-width: 280px;
}

.welcome-title {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    background: linear-gradient(135deg, #fff, #60a5fa);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.welcome-subtitle {
    font-size: 1.1rem;
    color: #cbd5e1;
    line-height: 1.5;
    margin-bottom: 2.5rem;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2.5rem;
}

.feature-item {
    background: rgba(255,255,255,0.05);
    backdrop-filter: blur(4px);
    border-radius: 20px;
    padding: 1.2rem;
    transition: transform 0.2s, background 0.2s;
}

    .feature-item:hover {
        background: rgba(255,255,255,0.1);
        transform: translateY(-4px);
    }

.feature-icon {
    width: 48px;
    height: 48px;
    background: #3b82f6;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1rem;
    font-size: 24px;
}

.feature-text h3 {
    font-size: 1.2rem;
    margin-bottom: 0.5rem;
}

.feature-text p {
    font-size: 0.85rem;
    color: #cbd5e1;
}

.dynamic-content {
    background: rgba(0,0,0,0.3);
    border-radius: 24px;
    padding: 1.5rem;
    margin-top: 1rem;
}

.dynamic-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.dynamic-title {
    font-size: 1.2rem;
    font-weight: 600;
}

.dynamic-header span {
    font-size: 0.75rem;
    color: #94a3b8;
}

.dynamic-items {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.dynamic-item {
    font-size: 0.9rem;
    color: #e2e8f0;
    padding: 0.5rem 0;
    border-bottom: 1px dashed rgba(255,255,255,0.05);
}

    .dynamic-item strong {
        color: #60a5fa;
    }

.login-section {
    flex: 1;
    max-width: 520px;
    min-width: 380px;
    background: rgba(15, 23, 42, 0.75);
    backdrop-filter: blur(12px);
    border-radius: 40px;
    padding: 2.5rem 2.8rem;
    border: 1px solid rgba(255,255,255,0.15);
    box-shadow: 0 30px 60px -15px rgba(0,0,0,0.4);
    transition: all 0.3s ease;
}

.login-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    padding-bottom: 0.75rem;
}

.tab-btn {
    background: transparent;
    border: none;
    padding: 0.5rem 1.2rem;
    font-size: 1rem;
    font-weight: 500;
    color: #94a3b8;
    cursor: pointer;
    border-radius: 40px;
    transition: all 0.2s;
}

    .tab-btn.active {
        background: #3b82f6;
        color: white;
    }

.login-form {
    display: none;
    animation: fadeIn 0.3s ease;
}

    .login-form.active {
        display: block;
    }

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

    .login-header h1 {
        font-size: 1.8rem;
        margin-bottom: 0.5rem;
    }

    .login-header p {
        color: #94a3b8;
    }

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

    .form-group label {
        display: block;
        margin-bottom: 0.5rem;
        font-weight: 500;
        font-size: 0.9rem;
    }

.input-with-icon {
    position: relative;
    display: flex;
    align-items: center;
}

.input-icon {
    position: absolute;
    left: 14px;
    color: #64748b;
    font-size: 1rem;
}

.input-with-icon input {
    width: 100%;
    padding: 12px 12px 12px 42px;
    background: rgba(0,0,0,0.4);
    border: 1px solid rgba(255,255,255,0.2);
    border-radius: 16px;
    font-size: 1rem;
    color: white;
    transition: 0.2s;
}

    .input-with-icon input:focus {
        outline: none;
        border-color: #3b82f6;
        background: rgba(0,0,0,0.6);
    }

.error-message {
    font-size: 0.75rem;
    color: #ef4444;
    margin-top: 0.25rem;
    display: none;
}

.login-btn {
    width: 100%;
    background: #3b82f6;
    border: none;
    padding: 12px;
    border-radius: 40px;
    font-size: 1rem;
    font-weight: 600;
    color: white;
    cursor: pointer;
    transition: 0.2s;
    margin-top: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

    .login-btn:hover {
        background: #2563eb;
        transform: translateY(-1px);
    }

.loading {
    display: inline-block;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 0.8s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.footer {
    text-align: center;
    padding: 2rem;
    color: #64748b;
    font-size: 0.8rem;
    border-top: 1px solid rgba(255,255,255,0.05);
}

    .footer a {
        color: #60a5fa;
        text-decoration: none;
    }

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    background: #1e293b;
    border-left: 4px solid #3b82f6;
    padding: 12px 20px;
    border-radius: 12px;
    color: white;
    z-index: 1000;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    max-width: 300px;
}

.captcha-group {
    display: flex;
    gap: 12px;
    align-items: center;
}

    .captcha-group .input-with-icon {
        flex: 1;
    }

.captcha-btn {
    background: rgba(59, 130, 246, 0.2);
    border: 1px solid rgba(59, 130, 246, 0.5);
    padding: 0 16px;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 500;
    color: #60a5fa;
    cursor: pointer;
    white-space: nowrap;
    transition: all 0.2s;
    height: 46px;
}

    .captcha-btn:hover:not(:disabled) {
        background: #3b82f6;
        color: white;
    }

    .captcha-btn:disabled {
        opacity: 0.5;
        cursor: not-allowed;
    }

.other-login {
    margin-top: 28px;
    text-align: center;
}

.divider {
    display: block;
    position: relative;
    font-size: 12px;
    color: #64748b;
    margin-bottom: 16px;
}

    .divider::before, .divider::after {
        content: '';
        position: absolute;
        top: 50%;
        width: calc(50% - 60px);
        height: 1px;
        background: rgba(255,255,255,0.1);
    }

    .divider::before {
        left: 0;
    }

    .divider::after {
        right: 0;
    }

.social-login {
    display: flex;
    justify-content: center;
}

.social-btn {
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    padding: 10px 24px;
    border-radius: 40px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

    .social-btn i {
        font-size: 18px;
    }

.wechat-btn {
    color: #07c160;
    border-color: rgba(7, 193, 96, 0.3);
}

    .wechat-btn:hover {
        background: #07c160;
        color: white;
    }

@media (max-width: 900px) {
    .main-content {
        flex-direction: column;
        gap: 32px;
    }

    .welcome-title {
        font-size: 2rem;
    }

    .login-section {
        width: 100%;
        max-width: none;
        min-width: auto;
        padding: 1.8rem;
        margin: 0 16px;
    }

    .captcha-group {
        flex-direction: column;
    }

    .captcha-btn {
        width: 100%;
        padding: 10px;
    }
}