:root {
    --bg-primary: #0a0e27;
    --bg-secondary: #151932;
    --bg-card: #1a1f3a;
    --text-primary: #ffffff;
    --text-secondary: #a0aec0;
    --accent-yellow: #ffd700;
    --accent-yellow-dark: #ffb700;
    --accent-blue: #4299e1;
    --border-color: #2d3748;
    --success: #48bb78;
    --error: #f56565;
    --shadow: rgba(0, 0, 0, 0.3);
}

[data-theme="light"] {
    --bg-primary: #f7fafc;
    --bg-secondary: #edf2f7;
    --bg-card: #ffffff;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --border-color: #e2e8f0;
    --shadow: rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    transition: all 0.3s ease;
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

#themeBtn {
    background: var(--bg-card);
    border: 2px solid var(--border-color);
    color: var(--accent-yellow);
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    font-size: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
    box-shadow: 0 4px 6px var(--shadow);
}

#themeBtn:hover {
    transform: scale(1.1);
    background: var(--accent-yellow);
    color: var(--bg-primary);
}

.container {
    width: 100%;
    max-width: 450px;
    animation: fadeInUp 0.6s ease;
}

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

.auth-card {
    background: var(--bg-card);
    border-radius: 20px;
    padding: 40px 30px;
    box-shadow: 0 20px 60px var(--shadow);
    border: 1px solid var(--border-color);
}

.logo {
    text-align: center;
    margin-bottom: 30px;
}

.logo i {
    font-size: 60px;
    color: var(--accent-yellow);
    margin-bottom: 10px;
    animation: rotate 3s linear infinite;
}

@keyframes rotate {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.logo h1 {
    font-size: 32px;
    background: linear-gradient(135deg, var(--accent-yellow) 0%, var(--accent-yellow-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    font-weight: 700;
}

.auth-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 30px;
    background: var(--bg-secondary);
    padding: 5px;
    border-radius: 12px;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: transparent;
    color: var(--text-secondary);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.tab-btn.active {
    background: var(--accent-yellow);
    color: var(--bg-primary);
}

.auth-form {
    display: none;
}

.auth-form.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 14px;
}

.form-group label i {
    color: var(--accent-yellow);
    margin-right: 5px;
}

.form-group input {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 15px;
    transition: all 0.3s ease;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-yellow);
    box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.1);
}

.password-input {
    position: relative;
}

.password-input input {
    padding-right: 50px;
}

.toggle-password {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 18px;
    padding: 5px;
    transition: color 0.3s ease;
}

.toggle-password:hover {
    color: var(--accent-yellow);
}

.password-strength {
    margin-top: 8px;
    height: 4px;
    border-radius: 2px;
    background: var(--border-color);
    overflow: hidden;
}

.password-strength::after {
    content: '';
    display: block;
    height: 100%;
    width: 0;
    background: var(--error);
    transition: all 0.3s ease;
}

.password-strength.weak::after {
    width: 33%;
    background: var(--error);
}

.password-strength.medium::after {
    width: 66%;
    background: var(--accent-yellow);
}

.password-strength.strong::after {
    width: 100%;
    background: var(--success);
}

.form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    font-size: 14px;
}

.checkbox {
    display: flex;
    align-items: center;
    cursor: pointer;
    color: var(--text-secondary);
}

.checkbox input {
    margin-right: 8px;
    cursor: pointer;
}

.checkbox.terms {
    margin-bottom: 20px;
}

.checkbox.terms span {
    line-height: 1.5;
}

.checkbox a {
    color: var(--accent-yellow);
    text-decoration: none;
}

.checkbox a:hover {
    text-decoration: underline;
}

.profile-upload {
    display: flex;
    gap: 15px;
    align-items: center;
    padding: 15px;
    background: var(--bg-secondary);
    border-radius: 12px;
    border: 2px dashed var(--border-color);
}

.profile-preview {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: var(--bg-card);
    border: 3px solid var(--accent-yellow);
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    flex-shrink: 0;
}

.profile-preview i {
    font-size: 50px;
    color: var(--text-secondary);
}

.profile-preview img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.upload-controls {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.btn-upload {
    padding: 10px 16px;
    border: 2px solid var(--accent-yellow);
    background: transparent;
    color: var(--accent-yellow);
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}

.btn-upload:hover {
    background: var(--accent-yellow);
    color: var(--bg-primary);
}

.btn-remove {
    padding: 10px;
    border: 2px solid var(--error);
    background: transparent;
    color: var(--error);
    border-radius: 8px;
    font-size: 14px;
    cursor: pointer;
    transition: all 0.3s ease;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-remove:hover {
    background: var(--error);
    color: white;
}

.forgot-link {
    color: var(--accent-yellow);
    text-decoration: none;
    font-weight: 500;
}

.forgot-link:hover {
    text-decoration: underline;
}

.btn-primary {
    width: 100%;
    padding: 16px;
    border: none;
    border-radius: 10px;
    background: linear-gradient(135deg, var(--accent-yellow) 0%, var(--accent-yellow-dark) 100%);
    color: var(--bg-primary);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(255, 215, 0, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(255, 215, 0, 0.4);
}

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

.divider {
    text-align: center;
    margin: 25px 0;
    position: relative;
}

.divider::before,
.divider::after {
    content: '';
    position: absolute;
    top: 50%;
    width: 40%;
    height: 1px;
    background: var(--border-color);
}

.divider::before {
    left: 0;
}

.divider::after {
    right: 0;
}

.divider span {
    background: var(--bg-card);
    padding: 0 15px;
    color: var(--text-secondary);
    font-size: 14px;
}

.btn-social {
    width: 100%;
    padding: 14px;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.btn-social:hover {
    border-color: var(--accent-yellow);
    background: var(--bg-card);
}

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

.features {
    display: flex;
    justify-content: space-around;
    margin-top: 30px;
    padding: 20px;
    background: var(--bg-card);
    border-radius: 15px;
    border: 1px solid var(--border-color);
}

.feature-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    text-align: center;
}

.feature-item i {
    font-size: 28px;
    color: var(--accent-yellow);
}

.feature-item span {
    font-size: 12px;
    color: var(--text-secondary);
    font-weight: 500;
}

.notification {
    position: fixed;
    top: 20px;
    left: 50%;
    transform: translateX(-50%) translateY(-100px);
    background: var(--bg-card);
    color: var(--text-primary);
    padding: 16px 24px;
    border-radius: 10px;
    box-shadow: 0 10px 30px var(--shadow);
    border: 2px solid var(--border-color);
    z-index: 2000;
    opacity: 0;
    transition: all 0.3s ease;
    max-width: 90%;
}

.notification.show {
    transform: translateX(-50%) translateY(0);
    opacity: 1;
}

.notification.success {
    border-color: var(--success);
}

.notification.error {
    border-color: var(--error);
}

/* Responsive Design */
@media (max-width: 480px) {
    .auth-card {
        padding: 30px 20px;
    }
    
    .logo h1 {
        font-size: 28px;
    }
    
    .logo i {
        font-size: 50px;
    }
    
    .features {
        flex-direction: column;
        gap: 15px;
    }
    
    .feature-item {
        flex-direction: row;
        justify-content: center;
    }
    
    .feature-item i {
        font-size: 24px;
    }
}