:root {
    --primary: #0d1117;
    --secondary: #161b22;
    --accent: #1a73e8;
    --danger: #ea4335;
    --success: #34a853;
    --warning: #fbbc05;
    --text: #e6edf3;
    --text-secondary: #8b949e;
    --border: #30363d;
    --card-bg: #161b22;
    --hover-bg: #21262d;
    --shadow: 0 8px 24px rgba(0, 0, 0, 0.5);
    --radius: 12px;
    --radius-sm: 8px;
    --transition: all 0.3s ease;
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--primary);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.auth-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.auth-nav {
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--secondary);
    border-bottom: 1px solid var(--border);
}

.back-btn {
    color: var(--text-secondary);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: var(--transition);
}

.back-btn:hover {
    color: var(--text);
}

.logo {
    font-size: 1.5rem;
    font-weight: 900;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 0.1rem;
}

.logo span {
    color: var(--accent);
}

.auth-content {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 1fr;
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
    gap: 3rem;
    align-items: center;
}

.auth-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.auth-tabs {
    display: flex;
    background: var(--secondary);
    border-bottom: 1px solid var(--border);
}

.tab-btn {
    flex: 1;
    padding: 1.25rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.tab-btn.active {
    color: var(--accent);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--accent);
}

.tab-content {
    padding: 2rem;
    display: none;
}

.tab-content.active {
    display: block;
}

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

.form-header h2 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
    color: var(--text);
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
}

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

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

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text);
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.password-input {
    position: relative;
}

.password-input input {
    width: 100%;
    padding: 1rem 3rem 1rem 1rem;
    background: var(--secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    color: var(--text);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.password-input input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(26, 115, 232, 0.1);
}

.toggle-password {
    position: absolute;
    right: 1rem;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1rem;
    padding: 0.25rem;
}

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

.password-strength {
    display: flex;
    gap: 4px;
    height: 4px;
    margin: 0.5rem 0;
}

.strength-bar {
    flex: 1;
    background: var(--border);
    border-radius: 2px;
    transition: var(--transition);
}

.strength-bar.weak {
    background: var(--danger);
}

.strength-bar.fair {
    background: var(--warning);
}

.strength-bar.good {
    background: #fbbc05;
}

.strength-bar.strong {
    background: var(--success);
}

.password-requirements {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    margin-top: 0.5rem;
}

.password-requirements span {
    font-size: 0.875rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.25rem;
}

.password-requirements span i {
    color: var(--success);
}

.btn {
    padding: 1rem 1.5rem;
    border-radius: var(--radius-sm);
    border: none;
    font-family: inherit;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.btn-primary {
    background: var(--accent);
    color: white;
}

.btn-primary:hover {
    background: #1669c1;
    transform: translateY(-2px);
}

.btn-block {
    width: 100%;
}

.form-footer {
    margin-top: 1.5rem;
    text-align: center;
}

.forgot-link {
    color: var(--accent);
    text-decoration: none;
    font-size: 0.95rem;
    transition: var(--transition);
}

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

.demo-note, .form-note {
    margin-top: 1rem;
    padding: 1rem;
    background: rgba(26, 115, 232, 0.1);
    border: 1px solid rgba(26, 115, 232, 0.3);
    border-radius: var(--radius-sm);
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    color: var(--text);
}

.demo-note i, .form-note i {
    color: var(--accent);
    margin-top: 0.125rem;
}

.auth-info {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.info-card {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    transition: var(--transition);
}

.info-card:hover {
    transform: translateY(-5px);
    border-color: var(--accent);
}

.info-icon {
    width: 48px;
    height: 48px;
    background: rgba(26, 115, 232, 0.1);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--accent);
    margin-bottom: 1rem;
}

.info-card h3 {
    font-size: 1.125rem;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.info-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
}

.auth-modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(5px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.auth-modal.active {
    display: flex;
}

.modal-content {
    background: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    max-width: 500px;
    width: 100%;
    box-shadow: var(--shadow);
    animation: modalSlideIn 0.3s ease;
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.modal-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 1.25rem;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    color: var(--text-secondary);
    cursor: pointer;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.modal-close:hover {
    background: var(--hover-bg);
    color: var(--text);
}

.modal-body {
    padding: 1.5rem;
}

.id-display {
    background: var(--secondary);
    border: 2px dashed var(--border);
    border-radius: var(--radius-sm);
    padding: 1.5rem;
    text-align: center;
    margin-bottom: 1.5rem;
}

.id-display code {
    font-family: 'JetBrains Mono', monospace;
    font-size: 1.5rem;
    color: var(--accent);
    font-weight: 600;
    letter-spacing: 1px;
}

.id-instructions {
    background: rgba(251, 188, 5, 0.1);
    border: 1px solid rgba(251, 188, 5, 0.3);
    border-radius: var(--radius-sm);
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.id-instructions p {
    margin-bottom: 0.5rem;
    color: var(--text);
    font-size: 0.95rem;
    display: flex;
    align-items: flex-start;
    gap: 0.5rem;
}

.id-instructions p:last-child {
    margin-bottom: 0;
}

.id-instructions i {
    color: var(--warning);
    margin-top: 0.125rem;
}

.id-actions {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 1rem;
}

.id-actions .btn {
    white-space: nowrap;
}

@media (max-width: 1024px) {
    .auth-content {
        grid-template-columns: 1fr;
        max-width: 600px;
    }
    
    .auth-info {
        order: -1;
    }
}

@media (max-width: 768px) {
    .auth-nav {
        padding: 1rem;
    }
    
    .auth-content {
        padding: 1rem;
    }
    
    .auth-card {
        border-radius: var(--radius-sm);
    }
    
    .tab-btn {
        padding: 1rem;
        font-size: 0.95rem;
    }
    
    .tab-content {
        padding: 1.5rem;
    }
    
    .id-actions {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .auth-content {
        padding: 1rem;
        gap: 2rem;
    }
    
    .form-header h2 {
        font-size: 1.5rem;
    }
    
    .password-requirements {
        flex-direction: column;
        gap: 0.5rem;
    }
    
    .info-card {
        padding: 1.25rem;
    }
}
/* Loading System */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--primary);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    opacity: 1;
    visibility: visible;
    transition: opacity 0.3s ease, visibility 0.3s ease;
}

.loading-overlay.hidden {
    opacity: 0;
    visibility: hidden;
}

.loading-spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    border-top-color: var(--accent);
    animation: spin 1s linear infinite;
    margin-bottom: 1.5rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.loading-text {
    color: var(--text);
    font-size: 1rem;
    font-weight: 500;
    margin-bottom: 0.5rem;
    text-align: center;
}

.loading-subtext {
    color: var(--text-secondary);
    font-size: 0.875rem;
    text-align: center;
    max-width: 300px;
}

/* Progress Bar */
.progress-bar {
    width: 300px;
    height: 4px;
    background: var(--border);
    border-radius: 2px;
    margin-top: 1rem;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    position: absolute;
    top: 0;
    left: 0;
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 2px;
}

/* Content fade-in animation */
.content-fade-in {
    animation: contentFadeIn 0.5s ease;
}

@keyframes contentFadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Page transition loader */
.page-transition-loader {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--border);
    z-index: 10000;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.page-transition-loader.active {
    opacity: 1;
}

.page-transition-progress {
    height: 100%;
    background: var(--accent);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 0 2px 2px 0;
}

/* Skeleton loading */
.skeleton {
    background: linear-gradient(90deg, var(--border) 25%, var(--hover-bg) 50%, var(--border) 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: var(--radius-sm);
}

@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.skeleton-text {
    height: 1rem;
    margin-bottom: 0.5rem;
}

.skeleton-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
}

.skeleton-card {
    padding: 1.5rem;
    border-radius: var(--radius);
}