/**
 * SignalFiles Mobile-First Responsive CSS
 * Modern, clean design optimized for mobile devices
 */

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

:root {
    --primary-color: #007bff;
    --primary-dark: #0056b3;
    --secondary-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --warning-color: #ffc107;
    --info-color: #17a2b8;
    --light-color: #f8f9fa;
    --dark-color: #343a40;
    --white: #ffffff;
    --black: #000000;
    --border-color: #dee2e6;
    --text-muted: #6c757d;
    --shadow: 0 2px 4px rgba(0,0,0,0.1);
    --shadow-lg: 0 4px 12px rgba(0,0,0,0.15);
    --border-radius: 8px;
    --border-radius-lg: 12px;
    --transition: all 0.3s ease;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--dark-color);
    background-color: var(--light-color);
    min-height: 100vh;
    overflow-x: hidden;
}

/* Container and Layout */
.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 16px;
}

.container-fluid {
    width: 100%;
    padding: 0 16px;
}

/* Header/Navigation */
.navbar {
    background: var(--white);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 12px 0;
}

.navbar-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
}

.navbar-brand:hover {
    color: var(--primary-dark);
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 4px;
    margin-left: auto;
}

.nav-link {
    padding: 8px 16px;
    color: var(--dark-color);
    text-decoration: none;
    border-radius: var(--border-radius);
    transition: var(--transition);
    font-weight: 500;
}

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

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

/* Mobile Navigation Toggle */
.navbar-toggler {
    display: none;
    background: none;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    padding: 8px;
    cursor: pointer;
}

.navbar-toggler-icon {
    width: 24px;
    height: 3px;
    background-color: var(--dark-color);
    display: block;
    position: relative;
    transition: var(--transition);
}

.navbar-toggler-icon::before,
.navbar-toggler-icon::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 3px;
    background-color: var(--dark-color);
    transition: var(--transition);
}

.navbar-toggler-icon::before {
    top: -8px;
}

.navbar-toggler-icon::after {
    bottom: -8px;
}

/* Main Content */
.main-content {
    padding: 24px 0;
    min-height: calc(100vh - 80px);
}

/* Cards */
.card {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
    overflow: hidden;
    border: 1px solid var(--border-color);
}

.card-header {
    padding: 20px 24px;
    background-color: var(--light-color);
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    font-size: 1.1rem;
}

.card-body {
    padding: 24px;
}

.card-footer {
    padding: 16px 24px;
    background-color: var(--light-color);
    border-top: 1px solid var(--border-color);
}

/* Statistics Cards */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 32px;
}

.stat-card {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    padding: 24px;
    text-align: center;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    display: block;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-top: 8px;
}

/* Forms */
.form-group {
    margin-bottom: 20px;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--dark-color);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 16px;
    transition: var(--transition);
    background-color: var(--white);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.1);
}

.form-control.is-invalid {
    border-color: var(--danger-color);
}

.form-control.is-valid {
    border-color: var(--success-color);
}

/* File Upload Zone */
.upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius-lg);
    padding: 48px 24px;
    text-align: center;
    background-color: var(--white);
    transition: var(--transition);
    cursor: pointer;
    margin-bottom: 24px;
}

.upload-zone:hover,
.upload-zone.dragover {
    border-color: var(--primary-color);
    background-color: rgba(0, 123, 255, 0.05);
}

.upload-zone.dragover {
    border-style: solid;
}

.upload-icon {
    font-size: 3rem;
    color: var(--text-muted);
    margin-bottom: 16px;
}

.upload-text {
    font-size: 1.1rem;
    color: var(--dark-color);
    margin-bottom: 8px;
}

.upload-subtext {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--border-radius);
    font-size: 16px;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: var(--transition);
    text-align: center;
    white-space: nowrap;
    min-height: 44px; /* Touch-friendly */
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

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

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

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

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

.btn-outline-primary:hover:not(:disabled) {
    background-color: var(--primary-color);
    color: var(--white);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 14px;
    min-height: 36px;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 18px;
    min-height: 52px;
}

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

/* File List */
.file-list {
    background: var(--white);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.file-item {
    display: flex;
    align-items: center;
    padding: 16px 20px;
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition);
}

.file-item:last-child {
    border-bottom: none;
}

.file-item:hover {
    background-color: var(--light-color);
}

.file-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--border-radius);
    background-color: var(--primary-color);
    color: var(--white);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    margin-right: 16px;
    flex-shrink: 0;
}

.file-info {
    flex: 1;
    min-width: 0;
}

.file-name {
    font-weight: 500;
    color: var(--dark-color);
    margin-bottom: 4px;
    word-break: break-word;
}

.file-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.file-actions {
    display: flex;
    gap: 8px;
    flex-shrink: 0;
    margin-left: 16px;
}

/* Alerts */
.alert {
    padding: 16px 20px;
    border-radius: var(--border-radius);
    margin-bottom: 20px;
    border: 1px solid transparent;
}

.alert-success {
    background-color: rgba(40, 167, 69, 0.1);
    border-color: var(--success-color);
    color: #155724;
}

.alert-danger {
    background-color: rgba(220, 53, 69, 0.1);
    border-color: var(--danger-color);
    color: #721c24;
}

.alert-warning {
    background-color: rgba(255, 193, 7, 0.1);
    border-color: var(--warning-color);
    color: #856404;
}

.alert-info {
    background-color: rgba(23, 162, 184, 0.1);
    border-color: var(--info-color);
    color: #0c5460;
}

/* Loading States */
.loading {
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-top: 2px solid var(--primary-color);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Progress Bar */
.progress {
    width: 100%;
    height: 8px;
    background-color: var(--border-color);
    border-radius: 4px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background-color: var(--primary-color);
    transition: width 0.3s ease;
}

/* Login Form */
.login-container {
    max-width: 400px;
    margin: 0 auto;
    padding: 40px 0;
}

.login-card {
    padding: 40px;
    text-align: center;
}

.login-logo {
    font-size: 2.5rem;
    color: var(--primary-color);
    margin-bottom: 24px;
}

.login-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 32px;
    color: var(--dark-color);
}

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 0 12px;
    }
    
    .navbar-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--white);
        flex-direction: column;
        padding: 16px;
        box-shadow: var(--shadow);
        border-top: 1px solid var(--border-color);
    }
    
    .navbar-nav.show {
        display: flex;
    }
    
    .navbar-toggler {
        display: block;
        margin-left: auto;
    }
    
    .stats-grid {
        grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
        gap: 12px;
    }
    
    .stat-card {
        padding: 16px;
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
    
    .card-body {
        padding: 16px;
    }
    
    .card-header {
        padding: 16px;
    }
    
    .file-item {
        padding: 12px 16px;
        flex-wrap: wrap;
    }
    
    .file-actions {
        width: 100%;
        margin-left: 0;
        margin-top: 12px;
        justify-content: flex-end;
    }
    
    .btn {
        min-height: 48px; /* Larger touch targets on mobile */
    }
    
    .btn-sm {
        min-height: 40px;
    }
    
    .upload-zone {
        padding: 32px 16px;
    }
    
    .login-card {
        padding: 24px;
    }
}

@media (max-width: 480px) {
    .file-meta {
        flex-direction: column;
        gap: 4px;
    }
    
    .stat-value {
        font-size: 1.25rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
}

/* Utility Classes */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.text-muted { color: var(--text-muted); }
.text-primary { color: var(--primary-color); }
.text-success { color: var(--success-color); }
.text-danger { color: var(--danger-color); }
.text-warning { color: var(--warning-color); }

.d-none { display: none; }
.d-block { display: block; }
.d-flex { display: flex; }
.d-inline-flex { display: inline-flex; }

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

.mt-1 { margin-top: 8px; }
.mt-2 { margin-top: 16px; }
.mt-3 { margin-top: 24px; }
.mb-1 { margin-bottom: 8px; }
.mb-2 { margin-bottom: 16px; }
.mb-3 { margin-bottom: 24px; }

.p-1 { padding: 8px; }
.p-2 { padding: 16px; }
.p-3 { padding: 24px; }

.w-100 { width: 100%; }
.h-100 { height: 100%; }