/* ========================================
   MSG to EML Converter - Modern Design 2025
   Email Transformation Hub Theme
   ======================================== */

/* ========================================
   1. CSS Variables - Email Blue Palette
   ======================================== */
:root {
    /* Primary Colors - Email Professional Theme */
    --primary: #0078D4;        /* Corporate blue (Outlook-inspired) */
    --primary-dark: #106EBE;
    --primary-light: #50A8FF;
    --secondary: #50E3C2;      /* Aqua green (success/conversion) */
    --accent: #FF6B35;         /* Orange (action/urgency) */

    /* Neutrals - Modern Palette */
    --surface: #F5F7FA;        /* Soft background */
    --surface-elevated: #FFFFFF;
    --surface-glass: rgba(255, 255, 255, 0.75);
    --text-primary: #1A1A1A;
    --text-secondary: #6B7280;
    --text-muted: #9CA3AF;

    /* Glassmorphism Effects */
    --glass-bg: rgba(255, 255, 255, 0.75);
    --glass-border: rgba(255, 255, 255, 0.3);
    --glass-shadow: 0 8px 32px rgba(0, 120, 212, 0.12);
    --glass-backdrop: blur(10px);

    /* Semantic Colors */
    --success: #10B981;
    --success-light: #D1FAE5;
    --danger: #EF4444;
    --danger-light: #FEE2E2;
    --warning: #F59E0B;
    --info: var(--primary);

    /* Spacing & Sizing */
    --border-radius: 16px;
    --border-radius-lg: 24px;
    --border-radius-sm: 8px;
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;

    /* Typography - Modern Font Stack */
    --font-display: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-body: 'Inter', system-ui, sans-serif;
    --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', monospace;

    /* Fluid Typography */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.375vw, 1rem);
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.625vw, 1.5rem);
    --text-xl: clamp(1.5rem, 1.25rem + 1.25vw, 2.25rem);
    --text-2xl: clamp(2rem, 1.5rem + 2.5vw, 3.5rem);

    /* Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.5s cubic-bezier(0.4, 0, 0.2, 1);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-base: 0 4px 6px rgba(0, 0, 0, 0.07);
    --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.15);
    --shadow-xl: 0 25px 50px rgba(0, 0, 0, 0.25);
}

/* ========================================
   2. Base Styles
   ======================================== */
* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-body);
    background: var(--surface);
    color: var(--text-primary);
    min-height: 100vh;
    padding: 20px 0;
    margin: 0;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ========================================
   3. Glassmorphic Header Bar (Fixed)
   ======================================== */
.user-info-bar {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-backdrop);
    -webkit-backdrop-filter: var(--glass-backdrop);
    border: 1px solid var(--glass-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-sm) var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    color: var(--text-primary);
    box-shadow: var(--glass-shadow);
    transition: all var(--transition-base);
}

.user-info-bar:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-2px);
}

.user-details {
    display: flex;
    align-items: center;
    font-weight: 500;
    color: var(--text-primary);
}

.user-name {
    font-size: var(--text-base);
    color: var(--text-primary);
}

.user-info-bar .btn-outline-light {
    border-color: var(--primary);
    color: var(--primary);
    background: transparent;
    transition: all var(--transition-base);
}

.user-info-bar .btn-outline-light:hover {
    background-color: var(--primary);
    border-color: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-base);
}

/* ========================================
   4. Hero Header Section
   ======================================== */
header {
    text-align: center;
    padding: var(--spacing-xl) 0;
    color: var(--text-primary);
}

header .mb-4 {
    margin-bottom: var(--spacing-md);
}

header .display-4 {
    font-size: var(--text-2xl);
    font-weight: 700;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.02em;
}

header .lead {
    font-size: var(--text-lg);
    color: var(--text-secondary);
    font-weight: 400;
    max-width: 600px;
    margin: 0 auto;
}

header small {
    color: var(--text-muted);
    font-size: var(--text-sm);
}

header a {
    color: var(--primary);
    text-decoration: underline;
    transition: color var(--transition-fast);
}

header a:hover {
    color: var(--primary-dark);
}

/* Email Conversion Icon Animation */
.conversion-icon {
    display: inline-block;
    animation: float 3s ease-in-out infinite;
    font-size: 4rem;
    color: var(--primary);
}

/* ========================================
   5. Main Card Container
   ======================================== */
.card {
    background: var(--surface-elevated);
    border: none;
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    overflow: hidden;
}

.card:hover {
    box-shadow: var(--shadow-xl);
}

.card-body {
    padding: var(--spacing-xl);
}

/* ========================================
   6. Upload Zone - Glassmorphic Design
   ======================================== */
.upload-zone {
    background: linear-gradient(135deg,
        rgba(0, 120, 212, 0.05) 0%,
        rgba(80, 227, 194, 0.05) 100%);
    backdrop-filter: var(--glass-backdrop);
    -webkit-backdrop-filter: var(--glass-backdrop);
    border: 2px dashed rgba(0, 120, 212, 0.3);
    border-radius: var(--border-radius-lg);
    padding: var(--spacing-xl);
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.upload-zone::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg,
        rgba(0, 120, 212, 0.02) 0%,
        rgba(80, 227, 194, 0.02) 100%);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.upload-zone:hover {
    border-color: var(--primary);
    background: linear-gradient(135deg,
        rgba(0, 120, 212, 0.1) 0%,
        rgba(80, 227, 194, 0.1) 100%);
    transform: translateY(-4px);
    box-shadow: var(--glass-shadow);
}

.upload-zone:hover::before {
    opacity: 1;
}

/* Dragover State */
.upload-zone.dragover {
    border-color: var(--secondary);
    border-width: 3px;
    border-style: solid;
    background: linear-gradient(135deg,
        rgba(80, 227, 194, 0.15) 0%,
        rgba(0, 120, 212, 0.15) 100%);
    transform: scale(1.02);
    box-shadow: 0 0 30px rgba(80, 227, 194, 0.3);
}

/* Upload Zone Icon */
.upload-zone .bi-cloud-upload {
    font-size: 3.5rem;
    color: var(--primary);
    animation: float 2s ease-in-out infinite;
}

.upload-zone h5 {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

.upload-zone p {
    color: var(--text-secondary);
    font-size: var(--text-base);
}

.upload-zone small {
    color: var(--text-muted);
    font-size: var(--text-sm);
}

/* ========================================
   7. File List - Modern Cards
   ======================================== */
#file-list h6 {
    font-size: var(--text-lg);
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-md);
}

.file-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
    background: var(--surface);
    border: 1px solid #E5E7EB;
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-sm);
    transition: all var(--transition-base);
}

.file-item:hover {
    background: var(--surface-elevated);
    border-color: var(--primary-light);
    transform: translateX(8px);
    box-shadow: var(--shadow-base);
}

.file-item .file-icon-container {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    flex: 1;
}

.file-item .bi-file-earmark-text {
    font-size: 1.5rem;
    color: var(--primary);
}

.file-item strong {
    color: var(--text-primary);
    font-weight: 600;
    font-size: var(--text-base);
}

.file-size {
    font-size: var(--text-sm);
    color: var(--text-muted);
    font-weight: 400;
}

.file-metadata {
    font-size: var(--text-xs);
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Conversion Arrow Icon */
.conversion-arrow {
    display: inline-block;
    font-size: 1.2rem;
    color: var(--secondary);
    margin: 0 0.5rem;
    animation: pulse 2s ease-in-out infinite;
}

/* ========================================
   8. Buttons - Modern Design
   ======================================== */
.btn {
    border-radius: var(--border-radius-sm);
    font-weight: 600;
    padding: 12px 24px;
    font-size: var(--text-base);
    transition: all var(--transition-base);
    border: none;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width var(--transition-base), height var(--transition-base);
}

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

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

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

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

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

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

.btn-success:hover {
    background: #059669;
    color: white;
}

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

.btn-outline-danger {
    background: transparent;
    border: 1px solid var(--danger);
    color: var(--danger);
}

.btn-outline-danger:hover {
    background: var(--danger);
    color: white;
}

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

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

.btn-lg {
    padding: 15px 32px;
    font-size: var(--text-lg);
}

.btn-sm {
    padding: 8px 16px;
    font-size: var(--text-sm);
}

.btn-remove {
    opacity: 0.6;
    transition: all var(--transition-fast);
}

.btn-remove:hover {
    opacity: 1;
    transform: scale(1.1) rotate(5deg);
}

.btn-download {
    background: linear-gradient(135deg, var(--success) 0%, #20c997 100%);
    border: none;
    color: white;
}

.btn-download:hover {
    background: linear-gradient(135deg, #20c997 0%, var(--success) 100%);
    color: white;
}

/* ========================================
   9. Progress Indicator - Modern Circular
   ======================================== */
.progress {
    border-radius: var(--border-radius);
    overflow: hidden;
    height: 40px;
    background-color: #E5E7EB;
    box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.1);
}

.progress-bar {
    font-size: var(--text-base);
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(90deg, var(--primary) 0%, var(--secondary) 100%);
    transition: width var(--transition-base);
    position: relative;
    overflow: hidden;
}

.progress-bar::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(
        90deg,
        transparent 0%,
        rgba(255, 255, 255, 0.3) 50%,
        transparent 100%
    );
    animation: shimmer 2s infinite;
}

#progress-text {
    position: relative;
    z-index: 1;
    color: white;
    font-weight: 700;
}

/* ========================================
   10. Results & Alerts
   ======================================== */
.alert {
    border-radius: var(--border-radius);
    border: none;
    padding: var(--spacing-md);
    box-shadow: var(--shadow-base);
}

.alert-success {
    background: var(--success-light);
    color: #065F46;
}

.alert-success .alert-heading {
    color: #065F46;
    font-weight: 700;
    font-size: var(--text-lg);
}

.alert-danger {
    background: var(--danger-light);
    color: #991B1B;
}

.alert-danger .alert-heading {
    color: #991B1B;
    font-weight: 700;
    font-size: var(--text-lg);
}

.alert hr {
    border-color: rgba(0, 0, 0, 0.1);
    margin: var(--spacing-md) 0;
}

/* ========================================
   11. Feature Cards Grid
   ======================================== */
.feature-box {
    background: var(--surface-elevated);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    text-align: center;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-base);
    border: 1px solid #E5E7EB;
    height: 100%;
}

.feature-box:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.feature-box i {
    font-size: 3rem;
    margin-bottom: var(--spacing-md);
    display: block;
}

.feature-box h5 {
    font-size: var(--text-lg);
    font-weight: 700;
    color: var(--text-primary);
    margin: var(--spacing-md) 0 var(--spacing-sm) 0;
}

.feature-box p {
    color: var(--text-secondary);
    font-size: var(--text-base);
    margin: 0;
    line-height: 1.6;
}

/* ========================================
   12. Footer
   ======================================== */
footer {
    text-align: center;
    padding: var(--spacing-xl) 0;
    color: var(--text-secondary);
    margin-top: var(--spacing-xl);
}

footer p {
    margin: 0.5rem 0;
}

footer small {
    font-size: var(--text-sm);
    color: var(--text-muted);
}

.footer-content {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-backdrop);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    display: inline-block;
    box-shadow: var(--shadow-sm);
}

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

@keyframes float {
    0%, 100% {
        transform: translateY(0px);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        opacity: 1;
    }
    50% {
        transform: scale(1.05);
        opacity: 0.8;
    }
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

@keyframes shake {
    0%, 100% { transform: translateX(0); }
    10%, 30%, 50%, 70%, 90% { transform: translateX(-5px); }
    20%, 40%, 60%, 80% { transform: translateX(5px); }
}

@keyframes slideInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes rotateIcon {
    from {
        transform: rotate(0deg);
    }
    to {
        transform: rotate(360deg);
    }
}

/* Animation Classes */
.fade-in {
    animation: fadeIn var(--transition-slow) ease-out;
}

.slide-in-up {
    animation: slideInUp var(--transition-slow) ease-out;
}

.shake {
    animation: shake 0.5s ease-in-out;
}

.pulse {
    animation: pulse 2s infinite;
}

/* ========================================
   14. Loading States
   ======================================== */
.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

.loading-skeleton {
    background: linear-gradient(
        90deg,
        #f0f0f0 25%,
        #e0e0e0 50%,
        #f0f0f0 75%
    );
    background-size: 200% 100%;
    animation: shimmer 2s infinite;
    border-radius: var(--border-radius-sm);
}

/* ========================================
   15. Accessibility
   ======================================== */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus Visible for Keyboard Navigation */
*:focus-visible {
    outline: 3px solid var(--primary);
    outline-offset: 2px;
}

/* Reduced Motion Support */
@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* ========================================
   16. Responsive Design - Mobile First
   ======================================== */
@media (max-width: 768px) {
    :root {
        --spacing-xl: 2rem;
        --spacing-lg: 1.5rem;
    }

    .container {
        padding: 0 var(--spacing-sm);
    }

    header {
        padding: var(--spacing-lg) 0;
    }

    header .display-4 {
        font-size: var(--text-xl);
    }

    .card-body {
        padding: var(--spacing-lg);
    }

    .upload-zone {
        padding: var(--spacing-lg);
        border-radius: var(--border-radius);
    }

    .upload-zone .bi-cloud-upload {
        font-size: 2.5rem;
    }

    .file-item {
        padding: var(--spacing-sm);
        font-size: var(--text-sm);
        flex-direction: column;
        align-items: flex-start;
        gap: var(--spacing-sm);
    }

    .file-item:hover {
        transform: translateY(-4px);
    }

    /* Touch-friendly buttons */
    .btn {
        min-height: 48px;
        min-width: 48px;
        padding: 14px 20px;
    }

    .btn-lg {
        min-height: 56px;
        padding: 16px 24px;
    }

    /* Stack features vertically */
    .feature-box {
        margin-bottom: var(--spacing-md);
    }

    .user-info-bar {
        padding: var(--spacing-sm);
    }

    .user-info-bar .d-flex {
        flex-direction: column;
        gap: var(--spacing-sm);
        align-items: flex-start !important;
    }
}

@media (max-width: 480px) {
    .upload-zone h5 {
        font-size: var(--text-base);
    }

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

/* ========================================
   17. Print Styles
   ======================================== */
@media print {
    body {
        background: white;
    }

    .user-info-bar,
    .upload-zone,
    .btn,
    footer {
        display: none;
    }

    .card {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}

/* ========================================
   18. Dark Mode Support (Future Enhancement)
   ======================================== */
@media (prefers-color-scheme: dark) {
    /* Dark mode variables can be added here in future */
}