/* ============================================================================
   Telegram Mini App - Modern Shop UI
   Дизайн: Минималистичный, элегантный, с плавными переходами
   ============================================================================ */

:root {
    /* Brand Colors */
    --color-primary: #3390ec;
    --color-primary-light: #54a3ef;
    --color-primary-dark: #2b7dd1;
    
    /* Accent Colors */
    --color-accent: #f5a524;
    --color-success: #4bb34b;
    --color-error: #e74c3c;
    --color-warning: #f39c12;
    
    /* Neutrals */
    --color-bg: #f8f9fa;
    --color-surface: #ffffff;
    --color-surface-hover: #f0f2f5;
    --color-border: #e4e6eb;
    --color-text-primary: #1c1e21;
    --color-text-secondary: #65676b;
    --color-text-tertiary: #8a8d91;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    
    /* Typography */
    --font-display: 'Syne', system-ui, -apple-system, sans-serif;
    --font-body: 'DM Sans', system-ui, -apple-system, sans-serif;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Layout */
    --header-height: 80px;
    --tab-nav-height: 60px;
    --bottom-nav-height: 72px;
    --safe-area-bottom: env(safe-area-inset-bottom, 0px);
}

/* ============================================================================
   Reset & Base Styles
   ============================================================================ */

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

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-body);
    font-size: 15px;
    line-height: 1.6;
    color: var(--color-text-primary);
    background: var(--color-bg);
    overflow-x: hidden;
    -webkit-tap-highlight-color: transparent;
}

/* ============================================================================
   Loading Screen
   ============================================================================ */

.loading-screen {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--color-bg);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}

.loading-content {
    text-align: center;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto var(--spacing-md);
}

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

.loading-text {
    color: var(--color-text-secondary);
    font-size: 14px;
    font-weight: 500;
}

/* ============================================================================
   Main Container
   ============================================================================ */

.main-container {
    min-height: 100vh;
    padding-bottom: calc(var(--bottom-nav-height) + var(--safe-area-bottom));
}

/* ============================================================================
   Header
   ============================================================================ */

.app-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) var(--spacing-md);
    animation: slideDown 0.4s var(--transition-base);
}

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

.header-content {
    max-width: 600px;
    margin: 0 auto;
}

.user-info {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.user-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    flex-shrink: 0;
}

.user-avatar svg {
    width: 24px;
    height: 24px;
}

.user-details {
    flex: 1;
}

.user-name {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
    line-height: 1.2;
    margin-bottom: 4px;
}

.balance-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--color-surface-hover);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 13px;
}

.balance-label {
    color: var(--color-text-tertiary);
    font-weight: 500;
}

.balance-amount {
    color: var(--color-primary);
    font-weight: 700;
}

/* ============================================================================
   Tab Navigation
   ============================================================================ */

.tab-nav {
    display: flex;
    gap: var(--spacing-sm);
    padding: var(--spacing-md);
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    overflow-x: auto;
    scrollbar-width: none;
    -ms-overflow-style: none;
    animation: slideDown 0.4s 0.1s var(--transition-base) backwards;
}

.tab-nav::-webkit-scrollbar {
    display: none;
}

.tab-btn {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px 16px;
    border: none;
    background: var(--color-bg);
    border-radius: var(--radius-lg);
    font-family: var(--font-body);
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-secondary);
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.tab-btn:hover {
    background: var(--color-surface-hover);
}

.tab-btn.active {
    background: var(--color-primary);
    color: white;
    box-shadow: var(--shadow-sm);
}

.tab-icon {
    font-size: 18px;
}

/* ============================================================================
   Main Content
   ============================================================================ */

.main-content {
    max-width: 600px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-md);
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s var(--transition-base);
}

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

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

.content-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

/* Section Hero */
.section-hero {
    text-align: center;
    padding: var(--spacing-md) 0;
}

.section-title {
    font-family: var(--font-display);
    font-size: 32px;
    font-weight: 800;
    color: var(--color-text-primary);
    line-height: 1.2;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    font-size: 15px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* ============================================================================
   Action Cards
   ============================================================================ */

.action-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.action-card {
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
}

.action-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.action-card:active {
    transform: translateY(0);
}

.action-card.primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-color: var(--color-primary);
    color: white;
}

.action-card.primary .action-title,
.action-card.primary .action-desc {
    color: white;
}

.action-card.secondary {
    background: var(--color-surface);
}

.action-icon {
    font-size: 36px;
    margin-bottom: var(--spacing-xs);
}

.action-title {
    font-family: var(--font-display);
    font-size: 18px;
    font-weight: 700;
    color: var(--color-text-primary);
    line-height: 1.2;
}

.action-desc {
    font-size: 13px;
    color: var(--color-text-secondary);
    line-height: 1.4;
}

/* ============================================================================
   Cards
   ============================================================================ */

.calculator-card,
.info-card,
.steps-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
}

.card-title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

/* Input Group */
.input-group {
    margin-bottom: var(--spacing-md);
}

.input-label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
}

.input-field {
    width: 100%;
    padding: 14px 16px;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 16px;
    color: var(--color-text-primary);
    background: var(--color-bg);
    transition: all var(--transition-fast);
}

.input-field:focus {
    outline: none;
    border-color: var(--color-primary);
    background: var(--color-surface);
}

.input-field::placeholder {
    color: var(--color-text-tertiary);
}

/* Calculation Result */
.calculation-result {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    border-radius: var(--radius-md);
    color: white;
}

.result-label {
    font-size: 14px;
    font-weight: 600;
    opacity: 0.9;
}

.result-value {
    font-family: var(--font-display);
    font-size: 24px;
    font-weight: 800;
}

.calc-note {
    margin-top: var(--spacing-sm);
    font-size: 13px;
    color: var(--color-text-tertiary);
    text-align: center;
}

/* Info Card */
.info-card {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.info-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.info-icon {
    font-size: 20px;
    flex-shrink: 0;
}

.info-text {
    font-size: 14px;
    font-weight: 500;
    color: var(--color-text-primary);
}

/* Steps Card */
.steps-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

.step-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.step-item:last-child {
    margin-bottom: 0;
}

.step-number {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--color-primary);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 14px;
    font-weight: 700;
    flex-shrink: 0;
}

.step-text {
    font-size: 14px;
    color: var(--color-text-primary);
    line-height: 1.5;
}

/* ============================================================================
   Premium Plans
   ============================================================================ */

.premium-plans {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.premium-plan {
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.premium-plan:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.premium-plan.popular {
    border-color: var(--color-accent);
    background: linear-gradient(135deg, rgba(245, 165, 36, 0.05), rgba(245, 165, 36, 0.1));
}

.plan-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    background: var(--color-accent);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.plan-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-md);
}

.plan-name {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
}

.plan-price {
    font-family: var(--font-display);
    font-size: 28px;
    font-weight: 800;
    color: var(--color-primary);
}

.plan-features {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.plan-features li {
    font-size: 14px;
    color: var(--color-text-secondary);
    padding-left: 24px;
    position: relative;
}

.plan-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--color-success);
    font-weight: 700;
}

/* ============================================================================
   Gifts Grid
   ============================================================================ */

.gifts-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md);
}

.gift-card {
    background: var(--color-surface);
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
}

.gift-card:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.gift-icon {
    font-size: 48px;
    margin-bottom: var(--spacing-sm);
}

.gift-name {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-xs);
}

.gift-price {
    font-size: 14px;
    color: var(--color-text-secondary);
    font-weight: 500;
}

/* ============================================================================
   Buttons
   ============================================================================ */

.btn-primary,
.btn-secondary {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 14px 24px;
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 16px;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: white;
    box-shadow: var(--shadow-sm);
}

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

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

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

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

.btn-icon {
    font-size: 20px;
}

.full-width {
    width: 100%;
}

/* ============================================================================
   Bottom Navigation
   ============================================================================ */

.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    display: flex;
    padding-bottom: var(--safe-area-bottom);
    z-index: 100;
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.04);
}

.nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-xs);
    border: none;
    background: transparent;
    cursor: pointer;
    transition: all var(--transition-fast);
    gap: 4px;
}

.nav-item:hover {
    background: var(--color-surface-hover);
}

.nav-item:active {
    transform: scale(0.95);
}

.nav-icon {
    width: 24px;
    height: 24px;
    color: var(--color-text-tertiary);
    transition: color var(--transition-fast);
}

.nav-item:hover .nav-icon {
    color: var(--color-primary);
}

.nav-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--color-text-tertiary);
    transition: color var(--transition-fast);
}

.nav-item:hover .nav-label {
    color: var(--color-primary);
}

/* ============================================================================
   Modal
   ============================================================================ */

.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: var(--spacing-lg);
    backdrop-filter: blur(4px);
}

.modal-overlay.active {
    display: flex;
    animation: fadeIn 0.2s var(--transition-base);
}

.modal {
    background: var(--color-surface);
    border-radius: var(--radius-xl);
    max-width: 480px;
    width: 100%;
    max-height: 80vh;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
    animation: slideUp 0.3s var(--transition-base);
}

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

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

.modal-title {
    font-family: var(--font-display);
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text-primary);
}

.modal-close {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--color-surface-hover);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.modal-close svg {
    width: 16px;
    height: 16px;
    color: var(--color-text-secondary);
}

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

.modal-body {
    padding: var(--spacing-lg);
    overflow-y: auto;
}

/* ============================================================================
   Snackbar
   ============================================================================ */

.snackbar {
    position: fixed;
    bottom: calc(var(--bottom-nav-height) + var(--spacing-md) + var(--safe-area-bottom));
    left: 50%;
    transform: translateX(-50%) translateY(100px);
    background: var(--color-text-primary);
    color: white;
    padding: 12px 20px;
    border-radius: var(--radius-lg);
    font-size: 14px;
    font-weight: 600;
    box-shadow: var(--shadow-lg);
    z-index: 2000;
    opacity: 0;
    pointer-events: none;
    transition: all var(--transition-base);
    max-width: calc(100% - 32px);
}

.snackbar.show {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
    pointer-events: auto;
}

.snackbar.success {
    background: var(--color-success);
}

.snackbar.error {
    background: var(--color-error);
}

.snackbar.warning {
    background: var(--color-warning);
}

/* ============================================================================
   Responsive Adjustments
   ============================================================================ */

@media (max-width: 360px) {
    .section-title {
        font-size: 28px;
    }
    
    .action-grid {
        grid-template-columns: 1fr;
    }
    
    .gifts-grid {
        grid-template-columns: 1fr;
    }
}