/* ===================================
   CSS Variables & Design Tokens
   Human-Centered Fintech Design
   =================================== */
:root {
    /* Soft Neutral Colors - Professional Banking Theme */
    --color-bg-primary: #fafbfc;
    --color-bg-secondary: #f5f7fa;
    --color-bg-tertiary: #ffffff;
    --color-bg-card: #ffffff;
    --color-bg-input: #f8f9fb;

    /* Text Colors - High Contrast for Accessibility */
    --color-text-primary: #1a1f36;
    --color-text-secondary: #4a5568;
    --color-text-tertiary: #697386;
    --color-text-muted: #8792a2;

    /* Accent Colors - Muted & Professional */
    --color-primary: #5469d4;
    --color-primary-hover: #4355c4;
    --color-primary-light: #e8ebf9;
    --color-success: #0ca678;
    --color-success-light: #d4f3e8;
    --color-danger: #e14747;
    --color-danger-light: #fce8e8;
    --color-border: #e3e8ef;
    --color-border-light: #f0f3f7;

    /* Spacing - Generous White Space */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Typography - Inter Font Family */
    --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', 'Roboto', sans-serif;

    /* Border Radius - Subtle */
    --border-radius-sm: 6px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;

    /* Shadows - Subtle */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.03);
    --shadow-md: 0 2px 4px 0 rgba(0, 0, 0, 0.04);
    --shadow-lg: 0 4px 8px 0 rgba(0, 0, 0, 0.06);

    /* Transitions - Smooth */
    --transition-base: 200ms ease;
}

/* ===================================
   Reset & Base Styles
   =================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family-primary);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    font-weight: 400;
}

/* Remove all background effects */
.bg-gradient,
.bg-grid {
    display: none;
}

/* ===================================
   Layout Components
   =================================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* ===================================
   Header
   =================================== */
.header {
    background: var(--color-bg-tertiary);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) 0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-xl);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 500;
    cursor: pointer;
    color: var(--color-text-primary);
}

.logo-icon {
    width: 24px;
    height: 24px;
    color: var(--color-primary);
}

.logo-text {
    color: var(--color-text-primary);
    font-weight: 500;
}

.logo-ai {
    font-size: 0.7em;
    vertical-align: super;
    color: var(--color-text-muted);
}

.nav {
    display: flex;
    gap: var(--spacing-sm);
}

.nav-link {
    color: var(--color-text-secondary);
    text-decoration: none;
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius-sm);
    font-weight: 400;
    font-size: 0.9375rem;
    transition: all var(--transition-base);
}

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

.nav-link.active {
    background-color: var(--color-primary-light);
    color: var(--color-primary);
}

.header-stats {
    display: flex;
    gap: var(--spacing-md);
}

.stat-badge {
    display: flex;
    flex-direction: column;
    align-items: flex-end;
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
}

.stat-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 500;
}

.stat-value {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-success);
}

/* ===================================
   Main Content
   =================================== */
.main {
    padding: var(--spacing-2xl) 0;
    min-height: calc(100vh - 200px);
}

/* ===================================
   Hero Section
   =================================== */
.hero {
    text-align: center;
    margin-bottom: var(--spacing-2xl);
}

.hero-title {
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 500;
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-primary);
    letter-spacing: -0.01em;
}

.gradient-text {
    color: var(--color-primary);
    font-weight: 500;
}

.hero-subtitle {
    font-size: 1rem;
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto;
    font-weight: 400;
}

/* ===================================
   Cards
   =================================== */
.card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border-light);
}

.card-title {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-text-primary);
}

.card-badge {
    padding: var(--spacing-xs) var(--spacing-md);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ===================================
   Grid Layout
   =================================== */
.grid-layout {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(500px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
}

@media (max-width: 1100px) {
    .grid-layout {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Forms
   =================================== */
.transaction-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.form-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--spacing-lg);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.form-label {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text-primary);
}

.label-icon {
    width: 16px;
    height: 16px;
    color: var(--color-text-muted);
}

.form-input,
.form-select {
    width: 100%;
    padding: 0.625rem 0.875rem;
    background: var(--color-bg-input);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-sm);
    color: var(--color-text-primary);
    font-family: var(--font-family-primary);
    font-size: 0.9375rem;
    font-weight: 400;
    transition: all var(--transition-base);
}

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

.form-input:focus,
.form-select:focus {
    outline: none;
    border-color: var(--color-primary);
    background: var(--color-bg-tertiary);
    box-shadow: 0 0 0 3px var(--color-primary-light);
}

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

/* ===================================
   Buttons
   =================================== */
.btn-primary,
.btn-secondary {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-sm);
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: var(--border-radius-sm);
    font-family: var(--font-family-primary);
    font-size: 0.9375rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
}

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

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

.btn-primary:active {
    transform: translateY(1px);
}

.btn-primary.loading {
    pointer-events: none;
    opacity: 0.7;
}

.btn-primary.loading .btn-text {
    opacity: 0;
}

.btn-primary.loading .btn-loader {
    display: block;
}

.btn-secondary {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    color: var(--color-text-secondary);
}

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

.btn-icon {
    width: 18px;
    height: 18px;
}

.btn-loader {
    display: none;
    position: absolute;
    width: 18px;
    height: 18px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-top-color: white;
    border-radius: 50%;
    animation: spin 0.6s linear infinite;
}

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

/* ===================================
   Results Display
   =================================== */
.results-content {
    min-height: 400px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.results-placeholder,
.history-placeholder {
    text-align: center;
    padding: var(--spacing-2xl);
}

.placeholder-icon {
    width: 64px;
    height: 64px;
    color: var(--color-text-muted);
    margin-bottom: var(--spacing-lg);
    opacity: 0.5;
}

.placeholder-text {
    color: var(--color-text-tertiary);
    font-size: 0.9375rem;
    font-weight: 400;
}

.result-display {
    width: 100%;
}

.result-status {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.status-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto var(--spacing-md);
    padding: var(--spacing-md);
    border-radius: 50%;
}

.status-icon.safe {
    background: var(--color-success-light);
    color: var(--color-success);
}

.status-icon.fraud {
    background: var(--color-danger-light);
    color: var(--color-danger);
}

.status-icon svg {
    width: 100%;
    height: 100%;
}

.status-title {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.status-title.safe {
    color: var(--color-success);
}

.status-title.fraud {
    color: var(--color-danger);
}

.status-subtitle {
    color: var(--color-text-secondary);
    font-size: 0.9375rem;
    font-weight: 400;
}

.confidence-meter {
    margin-bottom: var(--spacing-xl);
}

.confidence-label {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.confidence-value {
    font-weight: 500;
    color: var(--color-text-primary);
}

.confidence-bar {
    height: 8px;
    background: var(--color-bg-secondary);
    border-radius: var(--border-radius-sm);
    overflow: hidden;
}

.confidence-fill {
    height: 100%;
    border-radius: var(--border-radius-sm);
    transition: width 0.8s ease;
}

.confidence-fill.safe {
    background: var(--color-success);
}

.confidence-fill.fraud {
    background: var(--color-danger);
}

.result-details {
    display: grid;
    gap: var(--spacing-sm);
}

.detail-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: var(--spacing-md);
    background: var(--color-bg-secondary);
    border-radius: var(--border-radius-sm);
    transition: background var(--transition-base);
}

.detail-row:hover {
    background: var(--color-bg-primary);
}

.detail-label {
    color: var(--color-text-secondary);
    font-size: 0.875rem;
    font-weight: 400;
}

.detail-value {
    color: var(--color-text-primary);
    font-weight: 500;
}

/* ===================================
   History Section
   =================================== */
.history-section {
    margin-top: var(--spacing-2xl);
}

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

.section-title {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--color-text-primary);
}

.history-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: var(--spacing-lg);
}

.history-card {
    background: var(--color-bg-card);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius-md);
    padding: var(--spacing-lg);
    transition: all var(--transition-base);
}

.history-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-border);
}

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

.history-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--border-radius-sm);
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.history-status.safe {
    background: var(--color-success-light);
    color: var(--color-success);
}

.history-status.fraud {
    background: var(--color-danger-light);
    color: var(--color-danger);
}

.history-status-icon {
    width: 12px;
    height: 12px;
}

.history-time {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    font-weight: 400;
}

.history-amount {
    font-size: 1.5rem;
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.history-details {
    display: grid;
    gap: var(--spacing-xs);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
}

.history-detail {
    display: flex;
    justify-content: space-between;
}

.history-detail-label {
    color: var(--color-text-tertiary);
    font-weight: 400;
}

.history-detail-value {
    color: var(--color-text-primary);
    font-weight: 400;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-bg-tertiary);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0;
    margin-top: var(--spacing-2xl);
}

.footer-text {
    text-align: center;
    color: var(--color-text-tertiary);
    font-size: 0.875rem;
    font-weight: 400;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: var(--spacing-md);
    }

    .nav {
        width: 100%;
        justify-content: center;
    }

    .header-stats {
        width: 100%;
        justify-content: center;
    }

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

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

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

    .section-header {
        flex-direction: column;
        gap: var(--spacing-md);
        align-items: flex-start;
    }

    .hero-title {
        font-size: 1.75rem;
    }

    .hero-subtitle {
        font-size: 0.9375rem;
    }
}

/* ===================================
   Utility Classes
   =================================== */
.hidden {
    display: none !important;
}

/* ===================================
   Error Messaging
   =================================== */
.error-msg {
    background: var(--color-danger-light);
    border: 1px solid var(--color-danger);
    color: var(--color-danger);
    padding: var(--spacing-md);
    border-radius: var(--border-radius-sm);
    text-align: center;
    font-weight: 400;
    font-size: 0.9375rem;
    width: 100%;
}