* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}
body {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: #f1f5f9;
    padding: 20px;
}
.container {
    position: relative;
    width: 100%;
    max-width: 900px;
    height: 650px;
    background: #fff;
    border-radius: 20px;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}
.panel {
    position: absolute;
    top: 0;
    height: 100%;
    width: 50%;
    padding: 40px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    transition: all 0.6s ease-in-out;
    z-index: 1;
}
.login-panel {
    left: 0;
    opacity: 1;
    z-index: 2;
}
.register-panel {
    left: 0;
    transform: translateX(100%);
    opacity: 0;
}
.container.active .login-panel {
    transform: translateX(-100%);
    opacity: 0;
}
.container.active .register-panel {
    transform: translateX(0);
    opacity: 1;
    z-index: 2;
}
.panel h2 {
    text-align: center;
    font-size: 28px;
    color: #1e293b;
    margin-bottom: 30px;
}
.input-group {
    position: relative;
    margin-bottom: 20px;
}
.input-group i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: #94a3b8;
    font-size: 16px;
}
.input-group input {
    width: 100%;
    padding: 14px 15px 14px 45px;
    border: 1px solid #e2e8f0;
    border-radius: 10px;
    font-size: 15px;
    transition: 0.3s;
}
.input-group input:focus {
    outline: none;
    border-color: #6366f1;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}
.code-group {
    display: flex;
    gap: 10px;
}
.code-group input {
    flex: 1;
}
.code-btn {
    white-space: nowrap;
    padding: 0 15px;
    border: none;
    background: #6366f1;
    color: #fff;
    border-radius: 10px;
    cursor: pointer;
    font-size: 14px;
}
.code-btn:disabled {
    background: #94a3b8;
    cursor: not-allowed;
}
.btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 500;
    cursor: pointer;
    transition: 0.3s;
    margin-top: 10px;
}
.btn:hover {
    transform: scale(1.03);
}
.btn:active {
    transform: scale(0.98);
}
.link-text {
    text-align: center;
    margin-top: 20px;
    font-size: 14px;
    color: #64748b;
}
.link-text button {
    background: none;
    border: none;
    color: #6366f1;
    font-weight: 500;
    cursor: pointer;
    font-size: 14px;
}
.link-text button:hover {
    text-decoration: underline;
}
.overlay {
    position: absolute;
    top: 0;
    right: 0;
    width: 50%;
    height: 100%;
    background: linear-gradient(135deg, #6366f1, #8b5cf6);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    color: white;
    text-align: center;
    padding: 40px;
    z-index: 10;
}
.overlay i {
    font-size: 60px;
    margin-bottom: 20px;
}
.overlay h3 {
    font-size: 24px;
    margin-bottom: 10px;
}
.overlay p {
    font-size: 14px;
    opacity: 0.9;
    max-width: 250px;
}
@media (max-width: 768px) {
    .panel {
        width: 100%;
    }
    .overlay {
        display: none;
    }
}