:root {
    /* Colors */
    --color-bg-start: #0099ff;
    --color-bg-end: #0055ff;
    --color-white: #ffffff;
    --color-text-primary: #1a1f2e;
    --color-text-secondary: #5a6175;
    --color-text-light: #8b92a7;
    --color-primary: #007aff;
    --color-accent: #00c6ff;
    --color-success: #34c759;
    --color-error: #ff4949;
    --skeleton-base: #e4e9f1;
    --skeleton-highlight: #f3f6fb;

    /* Gradients */
    --gradient-bg: linear-gradient(180deg, #2ebf91 0%, #8360c3 100%);
    --gradient-app: linear-gradient(135deg, #00C6FF 0%, #0072FF 100%);
    --gradient-pill: linear-gradient(90deg, #00C6FF 0%, #0072FF 100%);
    --gradient-success: linear-gradient(135deg, #34c759 0%, #30b550 100%);
    --gradient-error: linear-gradient(135deg, #ff4949 0%, #ff6b6b 100%);

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Radius */
    --radius-sm: 12px;
    --radius-md: 16px;
    --radius-lg: 24px;
    --radius-pill: 50px;

    /* Fonts */
    --font-main: 'Outfit', sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-main);
    background: var(--gradient-app);
    color: var(--color-text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    -webkit-text-size-adjust: 100%;
    touch-action: manipulation;
}

.app-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
    background: var(--gradient-app);
}

.container {
    max-width: 480px;
    margin: 0 auto;
    padding: var(--spacing-md);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Main Content */
.main {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.tab-content {
    display: none;
    flex-direction: column;
    gap: var(--spacing-md);
    animation: fadeIn 0.4s ease;
}

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

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.15);
    position: relative;
    overflow: hidden;
}

.card-title {
    color: var(--color-primary);
    font-size: 1rem;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: var(--spacing-md);
    letter-spacing: 0.5px;
}

/* Form Elements */
.form-group {
    margin-bottom: var(--spacing-md);
}

.form-group:last-child {
    margin-bottom: 0;
}

.label {
    font-size: 0.75rem;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.05em;
    display: block;
    margin-bottom: var(--spacing-sm);
}

.value-input {
    width: 100%;
    padding: 14px var(--spacing-md);
    background: #f5f8fa;
    border: 2px solid transparent;
    border-radius: var(--radius-md);
    color: var(--color-text-primary);
    font-family: var(--font-main);
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
    outline: none;
}

.value-input:focus {
    border-color: var(--color-primary);
    background: white;
    box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.value-input::placeholder {
    color: var(--color-text-light);
}

/* Preset Amount Buttons */
.amount-presets {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
}

.preset-btn {
    padding: 12px 8px;
    background: #f5f8fa;
    border: 2px solid transparent;
    border-radius: var(--radius-sm);
    color: var(--color-text-primary);
    font-family: var(--font-mono);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

.preset-btn:hover,
.preset-btn:active {
    border-color: var(--color-primary);
    background: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 122, 255, 0.2);
}

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

/* Info Block */
.info-block {
    background: #f5f8fa;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-top: var(--spacing-md);
}

.info-item-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

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

.value {
    font-size: 1rem;
    font-weight: 600;
    color: var(--color-text-primary);
}

.value.mono {
    font-family: var(--font-mono);
}

/* Order Summary */
.order-summary {
    background: #f5f8fa;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
}

.summary-item {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    border-bottom: 1px solid #eef2f6;
}

.summary-item:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.summary-amounts {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    gap: 4px;
}

.summary-amounts #confirmAmountRub {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

/* Loading Indicator */
.loading-indicator {
    text-align: center;
    padding: var(--spacing-lg) var(--spacing-md);
    display: none;
}

.loading-indicator.active {
    display: block;
}

.spinner {
    width: 50px;
    height: 50px;
    margin: 0 auto var(--spacing-md);
    border: 4px solid rgba(0, 122, 255, 0.2);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.loading-indicator p {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    animation: pulse 1.5s ease-in-out infinite;
}

@keyframes pulse {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

/* Buttons */
.actions {
    display: flex;
    gap: var(--spacing-md);
    margin-top: auto;
    padding-top: var(--spacing-lg);
}

.btn {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 14px;
    border: none;
    border-radius: var(--radius-pill);
    font-family: var(--font-main);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
}

.btn-primary {
    background: var(--gradient-pill);
    color: white;
    box-shadow: 0 4px 15px rgba(0, 122, 255, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 122, 255, 0.4);
}

.btn-primary:active {
    transform: scale(0.98);
}

.btn-white {
    background: white;
    color: var(--color-text-primary);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-white:active {
    transform: scale(0.98);
}

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

.btn-icon {
    width: 20px;
    height: 20px;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: var(--spacing-md);
}

.action-buttons .btn {
    flex: 1;
}

/* Success Screen */
.success-card {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.success-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    background: var(--gradient-success);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 0 40px rgba(52, 199, 89, 0.4);
    animation: successPop 0.6s cubic-bezier(0.68, -0.55, 0.265, 1.55);
}

.success-icon svg {
    width: 48px;
    height: 48px;
}

@keyframes successPop {
    0% {
        transform: scale(0);
        opacity: 0;
    }
    50% {
        transform: scale(1.2);
    }
    100% {
        transform: scale(1);
        opacity: 1;
    }
}

.success-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: var(--spacing-md);
}

.success-message {
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.order-details {
    background: #f5f8fa;
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    text-align: left;
}

.detail-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Error Screen */
.error-card {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-lg);
}

.error-icon {
    width: 80px;
    height: 80px;
    margin: 0 auto var(--spacing-lg);
    background: var(--gradient-error);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    box-shadow: 0 0 40px rgba(255, 73, 73, 0.4);
    animation: errorShake 0.5s ease-in-out;
}

.error-icon svg {
    width: 48px;
    height: 48px;
}

@keyframes errorShake {
    0%, 100% { transform: translateX(0); }
    25% { transform: translateX(-10px); }
    75% { transform: translateX(10px); }
}

.error-title {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-error);
    margin-bottom: var(--spacing-md);
}

.error-message {
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: var(--spacing-lg);
}

.error-card .btn {
    max-width: 280px;
    margin: 0 auto;
}

/* Skeleton loading */
body.loading .skeleton-text {
    color: transparent;
    min-width: 80px;
    border-radius: 8px;
    background: linear-gradient(90deg, var(--skeleton-base) 25%, var(--skeleton-highlight) 50%, var(--skeleton-base) 75%);
    background-size: 200% 100%;
    animation: skeleton-shimmer 1.4s ease-in-out infinite;
}

body.loading .skeleton-text.narrow {
    min-width: 56px;
}

body.loading .skeleton-text.wide {
    min-width: 140px;
}

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

    100% {
        background-position: -200% 0;
    }
}

/* Responsive adjustments */
@media (max-width: 360px) {
    .amount-presets {
        grid-template-columns: repeat(2, 1fr);
    }

    .action-buttons {
        flex-direction: column;
    }
}