/* CSS Variables */
:root {
    --color-bg: #111111;
    --color-bg-card: #1C1C1C;
    --color-accent: #D4AF37;
    --color-text-primary: #FFFFFF;
    --color-text-secondary: #A0A0A0;
    --color-text-muted: #666666;
    --color-positive: #4CAF50;
    --color-negative: #F44336;

    --font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, sans-serif;

    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 12px;
    --spacing-lg: 16px;
    --spacing-xl: 20px;
    --spacing-2xl: 24px;
    --spacing-3xl: 28px;
    --spacing-4xl: 32px;

    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;

    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

/* Reset */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -webkit-tap-highlight-color: transparent;
}

body {
    font-family: var(--font-family);
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    min-height: 100vh;
    overflow-x: hidden;
    overflow-y: auto;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    /* Prevent pull-to-refresh and swipe gestures that might close the app */
    overscroll-behavior-y: contain;
    touch-action: pan-y;
}

/* App Container */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    max-width: 100%;
    margin: 0 auto;
    /* Prevent unwanted scroll behaviors */
    overscroll-behavior-y: contain;
    -webkit-overflow-scrolling: touch;
}

/* Top Header (based on Pencil design LkvkZ) */
.top-header {
    width: 100%;
    height: 97.92px;
    min-height: 97.92px;
    padding: 59px 0 0 0;
    margin: 0;
    /* Always visible to take space, but content is invisible until added */
    display: flex;
    align-items: flex-start;
    justify-content: center;
    text-align: center;
    border-bottom: 1px solid transparent;
    transition: all var(--transition-normal);
    /* Hide text content until it's added */
    visibility: hidden;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-bg);
    pointer-events: none;
    /* Text styles - exactly like .exchange-title */
    font-size: 18px;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--color-text-primary);
}

/* Show content when text is added */
.top-header:not(:empty) {
    visibility: visible;
    border-bottom-color: rgba(0, 0, 0, 0.1);
}

/* Header */
.header {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-4xl) var(--spacing-3xl) 0;
    padding-top: calc(77.92px + var(--spacing-4xl));
}

.logo {
    font-size: 42px;
    font-weight: 700;
    letter-spacing: -1px;
    line-height: 0.95;
    color: var(--color-text-primary);
    text-align: center;
}

.tagline {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 2px;
    color: var(--color-accent);
    text-transform: uppercase;
}

/* Content */
.content {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-4xl);
    padding: var(--spacing-4xl) var(--spacing-3xl);
}

/* Main Action Button */
.btn-main {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-md);
    width: 100%;
    height: 56px;
    background-color: var(--color-accent);
    border: none;
    border-radius: 0;
    cursor: pointer;
    transition: all var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
}

.btn-main:active {
    transform: scale(0.98);
    opacity: 0.9;
}

.btn-main .icon {
    width: 20px;
    height: 20px;
    color: var(--color-bg);
}

.btn-main span {
    font-family: var(--font-family);
    font-size: 13px;
    font-weight: 700;
    letter-spacing: 1px;
    color: var(--color-bg);
}

/* Buttons Grid */
.buttons-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

/* Animation for buttons */
@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.btn-row {
    display: flex;
    gap: var(--spacing-md);
}

.btn-secondary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    flex: 1;
    height: 56px;
    background-color: var(--color-bg-card);
    border: none;
    border-radius: 0;
    cursor: pointer;
    transition: all var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
    opacity: 0;
    transform: translateY(20px);
    animation: slideInUp 0.5s cubic-bezier(0.32, 0.72, 0, 1) forwards;
}

/* Cascade animation delays for buttons */
.buttons-grid .btn-row:nth-child(1) .btn-secondary:nth-child(1) {
    animation-delay: 0.1s;
}

.buttons-grid .btn-row:nth-child(1) .btn-secondary:nth-child(2) {
    animation-delay: 0.15s;
}

.buttons-grid .btn-row:nth-child(2) .btn-secondary:nth-child(1) {
    animation-delay: 0.2s;
}

.buttons-grid .btn-row:nth-child(2) .btn-secondary:nth-child(2) {
    animation-delay: 0.25s;
}

.buttons-grid .btn-secondary.btn-full:nth-of-type(1) {
    animation-delay: 0.3s;
}

.buttons-grid .btn-secondary.btn-full:nth-of-type(2) {
    animation-delay: 0.35s;
}

.btn-secondary:active {
    transform: scale(0.98);
    background-color: #252525;
}

.btn-secondary .icon {
    width: 18px;
    height: 18px;
    color: var(--color-accent);
    flex-shrink: 0;
}

.btn-secondary span {
    font-family: var(--font-family);
    font-size: 13px;
    font-weight: 600;
    letter-spacing: 1px;
    color: var(--color-text-primary);
}

.btn-full {
    flex: none;
    width: 100%;
}

.btn-outlined {
    border: 1px solid var(--color-accent);
}

/* Rate Section */
.rate-section {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

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

.accent-bar {
    width: 3px;
    height: 14px;
    background-color: var(--color-accent);
}

.section-title {
    font-size: 11px;
    font-weight: 600;
    letter-spacing: 2px;
    color: var(--color-text-secondary);
}

.rate-cards-row {
    display: flex;
    gap: 12px;
}

.rate-card {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    padding: 24px 20px;
    background-color: var(--color-bg-card);
    cursor: pointer;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    -webkit-tap-highlight-color: transparent;
}

.rate-card:active {
    transform: scale(0.98);
}

.rate-label-wrap {
    display: flex;
    align-items: center;
    gap: 8px;
}

.rate-label {
    font-family: var(--font-family);
    font-size: 10px;
    font-weight: 500;
    letter-spacing: 1.5px;
    color: #666666;
}

.rate-indicator {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    flex-shrink: 0;
}

.indicator-green {
    background-color: #4CAF50;
}

.indicator-red {
    background-color: #F44336;
}

.rate-value {
    font-size: 36px;
    font-weight: 700;
    letter-spacing: -2px;
    color: var(--color-text-primary);
}

.rate-currency {
    font-family: var(--font-family);
    font-size: 14px;
    font-weight: 500;
    color: var(--color-accent);
}

/* Rate cards loading state — skeleton shimmer */
.rate-cards-row.rate-loading .rate-value {
    color: transparent;
    min-width: 72px;
    min-height: 42px;
    position: relative;
    overflow: hidden;
    border-radius: 4px;
    background: rgba(255, 255, 255, 0.06);
}

.rate-cards-row.rate-loading .rate-value::after {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        105deg,
        transparent 0%,
        transparent 40%,
        rgba(255, 255, 255, 0.08) 50%,
        transparent 60%,
        transparent 100%
    );
    background-size: 200% 100%;
    animation: rateShimmer 1.5s ease-in-out infinite;
}

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

/* Loading States */
.btn-loading {
    pointer-events: none;
    opacity: 0.7;
}

.btn-loading::after {
    content: '';
    width: 16px;
    height: 16px;
    border: 2px solid transparent;
    border-top-color: currentColor;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-left: 8px;
}

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

/* Ripple Effect */
.ripple {
    position: relative;
    overflow: hidden;
}

.ripple::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease;
}

.ripple:active::after {
    width: 200%;
    height: 200%;
}

/* Skeleton Loading */
.skeleton {
    background: linear-gradient(90deg, var(--color-bg-card) 25%, #2a2a2a 50%, var(--color-bg-card) 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
}

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

/* Safe Area for iOS */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    .app-container {
        padding-bottom: env(safe-area-inset-bottom);
    }
}

/* Responsive */
@media (min-width: 420px) {
    .app-container {
        max-width: 420px;
        margin: 0 auto;
    }
}

/* Animation for page load */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.header {
    animation: fadeInUp 0.4s ease forwards;
}

.btn-main {
    animation: fadeInUp 0.4s ease 0.1s forwards;
    opacity: 0;
}

.buttons-grid {
    animation: fadeInUp 0.4s ease 0.2s forwards;
    opacity: 0;
}

.rate-section {
    animation: fadeInUp 0.4s ease 0.3s forwards;
    opacity: 0;
}

/* Dark mode specific (Telegram theme support) */
[data-theme="dark"] {
    --color-bg: #111111;
    --color-bg-card: #1C1C1C;
}

[data-theme="light"] {
    --color-bg: #F5F5F5;
    --color-bg-card: #FFFFFF;
    --color-text-primary: #111111;
    --color-text-secondary: #666666;
    --color-text-muted: #999999;
}

/* ========================================
   PAGE SYSTEM
   ======================================== */
.page {
    display: none;
    flex-direction: column;
    min-height: 100vh;
    width: 100%;
}

.page.active {
    display: flex;
    animation: fadeIn 0.3s ease;
}

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

@keyframes slideInRight {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@keyframes slideOutLeft {
    from {
        transform: translateX(0);
        opacity: 1;
    }
    to {
        transform: translateX(-100%);
        opacity: 0;
    }
}

.page-exchange.active {
    animation: slideInRight 0.3s ease;
}