/**
 * IPCASH Payment System - Premium Banking Design
 * Professional banking-grade UI/UX
 * Inspired by: Revolut, N26, Monzo, Tinkoff, Apple Card
 */

:root {
    /* Premium Color Palette - Banking Grade */
    --color-primary: #0A2540;
    --color-primary-dark: #061A2A;
    --color-primary-light: #1A3A5A;
    --color-accent: #0066FF;
    --color-accent-hover: #0052CC;
    --color-secondary: #1E3A5F;
    
    /* Status Colors */
    --color-success: #00C853;
    --color-success-light: #E8F5E9;
    --color-danger: #FF3B30;
    --color-danger-light: #FFEBEE;
    --color-warning: #FF9500;
    --color-warning-light: #FFF3E0;
    --color-info: #007AFF;
    --color-info-light: #E3F2FD;
    
    /* Neutrals - Premium Grays */
    --gray-50: #FAFBFC;
    --gray-100: #F4F6F8;
    --gray-200: #E8ECEF;
    --gray-300: #D1D8DD;
    --gray-400: #94A3B8;
    --gray-500: #64748B;
    --gray-600: #475569;
    --gray-700: #334155;
    --gray-800: #1E293B;
    --gray-900: #0F172A;
    
    /* Backgrounds */
    --bg-body: #FFFFFF;
    --bg-surface: #FFFFFF;
    --bg-surface-elevated: #FAFBFC;
    --bg-surface-hover: #F4F6F8;
    --bg-overlay: rgba(10, 37, 64, 0.8);
    
    /* Text */
    --text-primary: #0F172A;
    --text-secondary: #475569;
    --text-tertiary: #64748B;
    --text-disabled: #94A3B8;
    --text-inverse: #FFFFFF;
    
    /* Borders */
    --border-color: #E8ECEF;
    --border-color-hover: #D1D8DD;
    --border-radius: 8px;
    --border-radius-sm: 6px;
    --border-radius-lg: 12px;
    --border-radius-xl: 16px;
    --border-radius-2xl: 24px;
    
    /* Shadows - Premium Elevation */
    --shadow-xs: 0 1px 2px 0 rgba(10, 37, 64, 0.04);
    --shadow-sm: 0 1px 3px 0 rgba(10, 37, 64, 0.08), 0 1px 2px 0 rgba(10, 37, 64, 0.04);
    --shadow-md: 0 4px 6px -1px rgba(10, 37, 64, 0.08), 0 2px 4px -1px rgba(10, 37, 64, 0.04);
    --shadow-lg: 0 10px 15px -3px rgba(10, 37, 64, 0.1), 0 4px 6px -2px rgba(10, 37, 64, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(10, 37, 64, 0.1), 0 10px 10px -5px rgba(10, 37, 64, 0.04);
    --shadow-2xl: 0 25px 50px -12px rgba(10, 37, 64, 0.25);
    
    /* Spacing System */
    --spacing-0: 0;
    --spacing-1: 0.25rem;   /* 4px */
    --spacing-2: 0.5rem;    /* 8px */
    --spacing-3: 0.75rem;   /* 12px */
    --spacing-4: 1rem;     /* 16px */
    --spacing-5: 1.25rem;  /* 20px */
    --spacing-6: 1.5rem;   /* 24px */
    --spacing-8: 2rem;     /* 32px */
    --spacing-10: 2.5rem;  /* 40px */
    --spacing-12: 3rem;    /* 48px */
    --spacing-16: 4rem;    /* 64px */
    --spacing-20: 5rem;    /* 80px */
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', 'Roboto', 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', 'Monaco', 'Cascadia Code', 'Roboto Mono', monospace;
    
    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-smooth: 400ms cubic-bezier(0.25, 0.46, 0.45, 0.94);
}

/* Dark Theme - Premium Banking Dark Mode */
[data-theme="dark"] {
    --bg-body: #0F172A;
    --bg-surface: #1E293B;
    --bg-surface-elevated: #334155;
    --bg-surface-hover: #475569;
    --text-primary: #F8FAFC;
    --text-secondary: #CBD5E1;
    --text-tertiary: #94A3B8;
    --border-color: #334155;
    --border-color-hover: #475569;
    --overlay: rgba(0, 0, 0, 0.8);
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-sans);
    background: var(--bg-body);
    color: var(--text-primary);
    line-height: 1.6;
    font-weight: 400;
    min-height: 100vh;
}

/* Premium Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

h1 { 
    font-size: 3rem; 
    font-weight: 700;
    letter-spacing: -0.03em;
}
h2 { 
    font-size: 2.25rem; 
    font-weight: 700;
}
h3 { 
    font-size: 1.75rem; 
    font-weight: 600;
}
h4 { 
    font-size: 1.5rem; 
    font-weight: 600;
}
h5 { 
    font-size: 1.25rem; 
    font-weight: 600;
}
h6 { 
    font-size: 1.125rem; 
    font-weight: 600;
}

p {
    margin-bottom: var(--spacing-4);
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Premium Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 0.9375rem;
    font-weight: 500;
    font-family: var(--font-sans);
    border: none;
    border-radius: var(--border-radius-lg);
    cursor: pointer;
    transition: all var(--transition-base);
    text-decoration: none;
    gap: var(--spacing-2);
    white-space: nowrap;
    position: relative;
    overflow: hidden;
    letter-spacing: -0.01em;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--color-accent);
    color: var(--text-inverse);
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: var(--shadow-xs);
}

.btn-secondary {
    background: var(--bg-surface);
    color: var(--text-primary);
    border: 1.5px solid var(--border-color);
    box-shadow: var(--shadow-xs);
}

.btn-secondary:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-color-hover);
    box-shadow: var(--shadow-sm);
}

.btn-ghost {
    background: transparent;
    color: var(--text-primary);
    border: 1.5px solid transparent;
}

.btn-ghost:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-color);
}

.btn-lg {
    padding: 16px 32px;
    font-size: 1rem;
    border-radius: var(--border-radius-xl);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
    border-radius: var(--border-radius);
}

.btn-icon {
    padding: 12px;
    width: 44px;
    height: 44px;
}

/* Premium Cards */
.card {
    background: var(--bg-surface);
    border-radius: var(--border-radius-xl);
    padding: var(--spacing-6);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
    border: 1px solid var(--border-color);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
}

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

.card-elevated {
    box-shadow: var(--shadow-lg);
    border: none;
}

.card-header {
    margin-bottom: var(--spacing-6);
    padding-bottom: var(--spacing-4);
    border-bottom: 1px solid var(--border-color);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: var(--spacing-1);
    color: var(--text-primary);
}

.card-subtitle {
    color: var(--text-tertiary);
    font-size: 0.875rem;
    font-weight: 400;
}

/* Premium Forms */
.form-group {
    margin-bottom: var(--spacing-5);
}

.form-label {
    display: block;
    margin-bottom: var(--spacing-2);
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-primary);
    letter-spacing: -0.01em;
}

.form-input {
    width: 100%;
    padding: 12px 16px;
    font-size: 0.9375rem;
    font-family: var(--font-sans);
    border: 1.5px solid var(--border-color);
    border-radius: var(--border-radius-lg);
    background: var(--bg-surface);
    color: var(--text-primary);
    transition: all var(--transition-base);
    outline: none;
}

.form-input:hover {
    border-color: var(--border-color-hover);
}

.form-input:focus {
    border-color: var(--color-accent);
    box-shadow: 0 0 0 3px rgba(0, 102, 255, 0.1);
    background: var(--bg-surface-elevated);
}

.form-input::placeholder {
    color: var(--text-disabled);
}

.form-error {
    color: var(--color-danger);
    font-size: 0.8125rem;
    margin-top: var(--spacing-2);
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
}

/* Premium Alerts */
.alert {
    padding: var(--spacing-4) var(--spacing-5);
    border-radius: var(--border-radius-lg);
    margin-bottom: var(--spacing-4);
    border: 1px solid;
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-3);
    font-size: 0.9375rem;
}

.alert-success {
    background: var(--color-success-light);
    border-color: var(--color-success);
    color: #1B5E20;
}

.alert-danger {
    background: var(--color-danger-light);
    border-color: var(--color-danger);
    color: #B71C1C;
}

.alert-info {
    background: var(--color-info-light);
    border-color: var(--color-info);
    color: #0D47A1;
}

.alert-warning {
    background: var(--color-warning-light);
    border-color: var(--color-warning);
    color: #E65100;
}

/* Layout System */
.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

.container-sm {
    max-width: 640px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

.container-lg {
    max-width: 1536px;
    margin: 0 auto;
    padding: 0 var(--spacing-6);
}

/* Premium Navigation */
.navbar {
    background: var(--bg-surface);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-4) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(20px) saturate(180%);
    background: rgba(255, 255, 255, 0.8);
    box-shadow: var(--shadow-xs);
}

[data-theme="dark"] .navbar {
    background: rgba(30, 41, 59, 0.8);
}

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

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
    display: flex;
    align-items: center;
    gap: var(--spacing-2);
}

.navbar-brand::before {
    content: '💳';
    font-size: 1.75rem;
}

.navbar-nav {
    display: flex;
    align-items: center;
    gap: var(--spacing-1);
    list-style: none;
}

.navbar-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    padding: var(--spacing-2) var(--spacing-4);
    border-radius: var(--border-radius);
    transition: all var(--transition-fast);
    position: relative;
}

.navbar-link:hover {
    color: var(--text-primary);
    background: var(--bg-surface-hover);
}

.navbar-link.active {
    color: var(--color-accent);
    background: rgba(0, 102, 255, 0.08);
}

/* Premium Stats */
.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: var(--spacing-4);
}

.stat-card {
    background: var(--bg-surface);
    padding: var(--spacing-5);
    border-radius: var(--border-radius-xl);
    border: 1px solid var(--border-color);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--color-accent), var(--color-primary));
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--border-color-hover);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--spacing-2);
    letter-spacing: -0.02em;
    font-variant-numeric: tabular-nums;
}

.stat-label {
    color: var(--text-tertiary);
    font-size: 0.8125rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Premium Grid */
.grid {
    display: grid;
    gap: var(--spacing-4);
}

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

.grid-3 {
    grid-template-columns: repeat(3, 1fr);
}

.grid-4 {
    grid-template-columns: repeat(4, 1fr);
}

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

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.fade-in {
    animation: fadeIn 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

.slide-in {
    animation: slideIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

.scale-in {
    animation: scaleIn 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Premium Loading States */
.loading {
    position: relative;
    pointer-events: none;
    opacity: 0.6;
}

.loading::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 20px;
    height: 20px;
    margin: -10px 0 0 -10px;
    border: 2px solid var(--border-color);
    border-top-color: var(--color-accent);
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

/* Responsive Design */
@media (max-width: 1024px) {
    .container {
        padding: 0 var(--spacing-4);
    }
    
    h1 { font-size: 2.5rem; }
    h2 { font-size: 2rem; }
    h3 { font-size: 1.5rem; }
}

@media (max-width: 768px) {
    .grid-2,
    .grid-3,
    .grid-4 {
        grid-template-columns: 1fr;
    }
    
    .stats {
        grid-template-columns: 1fr;
    }
    
    .navbar-nav {
        flex-direction: column;
        gap: var(--spacing-2);
    }
    
    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }
    
    .card {
        padding: var(--spacing-4);
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.mt-1 { margin-top: var(--spacing-1); }
.mt-2 { margin-top: var(--spacing-2); }
.mt-3 { margin-top: var(--spacing-3); }
.mt-4 { margin-top: var(--spacing-4); }
.mt-6 { margin-top: var(--spacing-6); }
.mt-8 { margin-top: var(--spacing-8); }

.mb-1 { margin-bottom: var(--spacing-1); }
.mb-2 { margin-bottom: var(--spacing-2); }
.mb-3 { margin-bottom: var(--spacing-3); }
.mb-4 { margin-bottom: var(--spacing-4); }
.mb-6 { margin-bottom: var(--spacing-6); }
.mb-8 { margin-bottom: var(--spacing-8); }

.hidden { display: none; }
.flex { display: flex; }
.flex-center { 
    display: flex; 
    align-items: center; 
    justify-content: center; 
}
.flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.gap-2 { gap: var(--spacing-2); }
.gap-3 { gap: var(--spacing-3); }
.gap-4 { gap: var(--spacing-4); }

/* Premium Scrollbar */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-surface);
}

::-webkit-scrollbar-thumb {
    background: var(--gray-300);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--gray-400);
}

/* Selection */
::selection {
    background: rgba(0, 102, 255, 0.2);
    color: var(--text-primary);
}