:root {
    --tg-theme-bg-color: #ffffff;
    --tg-theme-text-color: #000000;
    --tg-theme-hint-color: #999999;
    --tg-theme-link-color: #2481cc;
    --tg-theme-button-color: #2481cc;
    --tg-theme-button-text-color: #ffffff;
    --tg-theme-secondary-bg-color: #f4f4f5;

    --primary-color: #2481cc;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --premium-color: #ffd700;

    --border-radius: 12px;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--tg-theme-bg-color);
    color: var(--tg-theme-text-color);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}

/* Loading Screen */
.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background-color: var(--tg-theme-bg-color);
    z-index: 9999;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--tg-theme-secondary-bg-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* Main Container */
.main-container {
    min-height: 100vh;
    padding-bottom: 80px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary-color), #1a6db8);
    color: white;
    padding: 20px;
    box-shadow: var(--shadow-md);
}

.header-content {
    max-width: 1200px;
    margin: 0 auto;
}

.header h1 {
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 8px;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 10px;
}

.user-name {
    font-size: 14px;
    opacity: 0.9;
}

/* Badge */
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.badge-premium {
    background: var(--premium-color);
    color: #000;
}

.badge-secondary {
    background: var(--secondary-color);
    color: white;
}

/* Navigation */
.nav-tabs {
    display: flex;
    background: white;
    border-bottom: 1px solid #e5e5e5;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-sm);
}

.nav-tab {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 8px;
    border: none;
    background: transparent;
    color: var(--tg-theme-hint-color);
    font-size: 12px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    border-bottom: 2px solid transparent;
}

.nav-tab.active {
    color: var(--primary-color);
    border-bottom-color: var(--primary-color);
}

.nav-tab .icon {
    width: 24px;
    height: 24px;
    stroke-width: 2;
}

/* Tab Content */
.tab-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.3s;
}

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

/* Cards */
.card {
    background: white;
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 20px;
    box-shadow: var(--shadow-sm);
}

.card h2, .card h3 {
    margin-bottom: 16px;
    font-size: 18px;
    font-weight: 600;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.stat-card {
    background: white;
    border-radius: var(--border-radius);
    padding: 20px;
    box-shadow: var(--shadow-sm);
    display: flex;
    align-items: center;
    gap: 15px;
}

.stat-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--primary-color), #1a6db8);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.stat-icon svg {
    width: 24px;
    height: 24px;
    stroke: white;
    stroke-width: 2;
}

.stat-info {
    flex: 1;
}

.stat-label {
    font-size: 12px;
    color: var(--tg-theme-hint-color);
    margin-bottom: 4px;
}

.stat-value {
    font-size: 24px;
    font-weight: 700;
    color: var(--tg-theme-text-color);
}

/* Form Elements */
.form-group {
    margin-bottom: 20px;
}

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

.input, .textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #e5e5e5;
    border-radius: 8px;
    font-size: 14px;
    font-family: inherit;
    background: var(--tg-theme-bg-color);
    color: var(--tg-theme-text-color);
    transition: border-color 0.3s;
}

.input:focus, .textarea:focus {
    outline: none;
    border-color: var(--primary-color);
}

.textarea {
    resize: vertical;
    min-height: 100px;
}

.help-text {
    display: block;
    margin-top: 6px;
    font-size: 12px;
    color: var(--tg-theme-hint-color);
}

.text-muted {
    color: var(--tg-theme-hint-color);
    font-size: 14px;
    margin-bottom: 16px;
}

/* Checkbox */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    font-size: 14px;
}

.checkbox-label input[type="checkbox"] {
    width: 20px;
    height: 20px;
    cursor: pointer;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
    text-align: center;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color), #1a6db8);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

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

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

.btn-block {
    display: block;
    width: 100%;
}

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

/* Features List */
.features-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.feature-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px;
    background: var(--tg-theme-secondary-bg-color);
    border-radius: 8px;
}

.check-icon {
    width: 20px;
    height: 20px;
    stroke: var(--success-color);
    stroke-width: 3;
    flex-shrink: 0;
}

/* Progress Bar */
.progress-bar {
    width: 100%;
    height: 8px;
    background: var(--tg-theme-secondary-bg-color);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 12px;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary-color), var(--success-color));
    transition: width 0.3s;
    width: 0%;
}

.status-text {
    font-size: 14px;
    color: var(--tg-theme-hint-color);
    text-align: center;
}

/* Session Status */
.session-status {
    background: var(--tg-theme-secondary-bg-color);
    padding: 15px;
    border-radius: 8px;
    margin-bottom: 16px;
}

.session-info {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

#session-details p {
    margin: 8px 0;
    font-size: 14px;
}

/* Premium Section */
.premium-header {
    text-align: center;
    margin-bottom: 30px;
    padding: 30px 20px;
    background: linear-gradient(135deg, var(--primary-color), #1a6db8);
    color: white;
    border-radius: var(--border-radius);
}

.premium-header h2 {
    font-size: 28px;
    margin-bottom: 8px;
    color: white;
}

.premium-header p {
    font-size: 16px;
    opacity: 0.9;
}

.premium-features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.premium-feature {
    display: flex;
    align-items: flex-start;
    gap: 15px;
    padding: 20px;
    background: white;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.premium-icon {
    width: 32px;
    height: 32px;
    stroke: var(--primary-color);
    stroke-width: 2;
    flex-shrink: 0;
}

.premium-feature h3 {
    font-size: 16px;
    margin-bottom: 4px;
}

.premium-feature p {
    font-size: 14px;
    color: var(--tg-theme-hint-color);
}

/* Pricing Grid */
.pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-bottom: 20px;
}

.price-card {
    background: white;
    border: 2px solid #e5e5e5;
    border-radius: var(--border-radius);
    padding: 20px;
    text-align: center;
    transition: all 0.3s;
    position: relative;
}

.price-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.price-card.popular, .price-card.best-value {
    border-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(36, 129, 204, 0.05), rgba(26, 109, 184, 0.05));
}

.popular-badge {
    position: absolute;
    top: -12px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--premium-color);
    color: #000;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 700;
    white-space: nowrap;
}

.price-header {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 10px;
    color: var(--tg-theme-text-color);
}

.price-amount {
    font-size: 32px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.price-period {
    font-size: 14px;
    color: var(--tg-theme-hint-color);
    margin-bottom: 15px;
}

.price-card .btn {
    width: 100%;
    padding: 10px;
    font-size: 13px;
}

.premium-expiry {
    font-size: 18px;
    font-weight: 600;
    color: var(--premium-color);
    text-align: center;
    margin-top: 10px;
}

/* Responsive Design */
@media (max-width: 768px) {
    .tab-content {
        padding: 15px;
    }

    .stats-grid {
        grid-template-columns: 1fr;
    }

    .premium-features {
        grid-template-columns: 1fr;
    }

    .pricing-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .price-amount {
        font-size: 24px;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 20px;
    }

    .nav-tab {
        font-size: 11px;
        padding: 10px 4px;
    }

    .nav-tab .icon {
        width: 20px;
        height: 20px;
    }

    .pricing-grid {
        grid-template-columns: 1fr;
    }
}

/* Animations */
@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.card, .stat-card, .premium-feature, .price-card {
    animation: slideUp 0.5s ease-out;
}