/**
 * FAKTURAČNÍ SYSTÉM - Hlavní CSS
 * Design inspirovaný fakturou: čisté, profesionální barvy
 * Bootstrap 5.3 + Custom CSS4
 */

/* =============================================
   CSS PROMĚNNÉ (Custom Properties)
   ============================================= */
:root {
    /* Primární barvy */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    
    /* Textové barvy */
    --text-dark: #1f2937;
    --text-medium: #374151;
    --text-light: #6b7280;
    --text-lighter: #9ca3af;
    
    /* Stavové barvy */
    --success-color: #10b981;
    --success-light: #34d399;
    --warning-color: #f59e0b;
    --warning-light: #fbbf24;
    --danger-color: #ef4444;
    --danger-light: #f87171;
    --info-color: #3b82f6;
    
    /* Pozadí */
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-lighter: #f3f4f6;
    
    /* Ohraničení */
    --border-color: #e5e7eb;
    --border-light: #f3f4f6;
    
    /* Stíny */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Přechody */
    --transition-fast: all 0.15s ease;
    --transition-normal: all 0.3s ease;
    --transition-slow: all 0.5s ease;
    
    /* Border radius */
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
}

/* =============================================
   GLOBÁLNÍ STYLY
   ============================================= */
* {
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-light);
    color: var(--text-dark);
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

/* =============================================
   NAVIGACE
   ============================================= */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow-md);
    padding: 1rem 0;
    border-bottom: 1px solid var(--border-color);
}

.navbar-brand {
    font-weight: 700;
    color: var(--primary-color) !important;
    font-size: 1.5rem;
    transition: var(--transition-fast);
}

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

.navbar-nav .nav-link {
    color: var(--text-dark);
    font-weight: 500;
    padding: 0.5rem 1rem;
    transition: var(--transition-fast);
    border-radius: var(--radius-sm);
}

.navbar-nav .nav-link:hover {
    color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.05);
}

.navbar-nav .nav-link.active {
    color: var(--primary-color);
    background-color: rgba(37, 99, 235, 0.1);
}

.dropdown-menu {
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-lg);
    border-radius: var(--radius-md);
}

.dropdown-item {
    padding: 0.5rem 1rem;
    transition: var(--transition-fast);
}

.dropdown-item:hover {
    background-color: var(--bg-light);
    color: var(--primary-color);
}

/* =============================================
   PŘIHLAŠOVACÍ STRÁNKA
   ============================================= */
.login-page {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.login-container {
    background: var(--bg-white);
    border-radius: var(--radius-xl);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
    max-width: 440px;
    width: 100%;
    animation: fadeInUp 0.5s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.login-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 40px 30px;
    text-align: center;
}

.login-header h1 {
    font-size: 28px;
    font-weight: 700;
    margin: 0 0 10px 0;
}

.login-header p {
    margin: 0;
    opacity: 0.9;
    font-size: 14px;
}

.login-body {
    padding: 40px 30px;
}

.login-footer {
    text-align: center;
    padding: 20px;
    background-color: var(--bg-light);
    border-top: 1px solid var(--border-color);
    font-size: 13px;
    color: var(--text-light);
}

.security-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12px;
    color: var(--text-light);
    margin-top: 15px;
}

.security-badge svg {
    width: 16px;
    height: 16px;
}

/* =============================================
   FORMULÁŘE
   ============================================= */
.form-label {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 8px;
    font-size: 14px;
}

.form-control {
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    font-size: 15px;
    transition: var(--transition-normal);
}

.form-control:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
    outline: none;
}

.form-control:disabled,
.form-control[readonly] {
    background-color: var(--bg-lighter);
    cursor: not-allowed;
}

.form-select {
    border: 2px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 12px 16px;
    font-size: 15px;
    transition: var(--transition-normal);
}

.form-select:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.1);
    outline: none;
}

textarea.form-control {
    min-height: 100px;
    resize: vertical;
}

/* =============================================
   TLAČÍTKA
   ============================================= */
.btn-primary-custom {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border: none;
    border-radius: var(--radius-md);
    padding: 0.625rem 1.25rem;
    font-weight: 600;
    color: white;
    transition: var(--transition-normal);
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    cursor: pointer;
}

.btn-primary-custom:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(37, 99, 235, 0.3);
    color: white;
}

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

.btn-login {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-dark) 100%);
    border: none;
    border-radius: var(--radius-md);
    padding: 14px;
    font-size: 16px;
    font-weight: 600;
    color: white;
    width: 100%;
    margin-top: 10px;
    transition: var(--transition-normal);
    cursor: pointer;
}

.btn-login:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 25px rgba(37, 99, 235, 0.3);
}

.btn-action {
    padding: 0.375rem 0.5rem;
    border-radius: var(--radius-sm);
    border: none;
    background: transparent;
    color: var(--text-light);
    transition: var(--transition-fast);
    cursor: pointer;
    font-size: 1.1rem;
}

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

.btn-danger-custom {
    background-color: var(--danger-color);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: var(--radius-md);
    font-weight: 600;
    transition: var(--transition-fast);
}

.btn-danger-custom:hover {
    background-color: #dc2626;
    transform: translateY(-1px);
}

/* =============================================
   ALERTY
   ============================================= */
.alert {
    border: none;
    border-radius: var(--radius-md);
    padding: 14px 18px;
    font-size: 14px;
    margin-bottom: 20px;
}

.alert-danger {
    background-color: #fee;
    color: var(--danger-color);
    border-left: 4px solid var(--danger-color);
}

.alert-success {
    background-color: #eff;
    color: var(--success-color);
    border-left: 4px solid var(--success-color);
}

.alert-warning {
    background-color: #fffbeb;
    color: var(--warning-color);
    border-left: 4px solid var(--warning-color);
}

.alert-info {
    background-color: #eff6ff;
    color: var(--info-color);
    border-left: 4px solid var(--info-color);
}

/* =============================================
   STATISTICKÉ KARTY
   ============================================= */
.stats-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: var(--transition-normal);
    border: 1px solid var(--border-light);
}

.stats-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
}

.stats-card .stats-icon {
    width: 48px;
    height: 48px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    margin-bottom: 1rem;
}

.stats-card.primary .stats-icon {
    background-color: rgba(37, 99, 235, 0.1);
    color: var(--primary-color);
}

.stats-card.success .stats-icon {
    background-color: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
}

.stats-card.warning .stats-icon {
    background-color: rgba(245, 158, 11, 0.1);
    color: var(--warning-color);
}

.stats-card.danger .stats-icon {
    background-color: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
}

.stats-card h3 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
    color: var(--text-dark);
}

.stats-card p {
    margin: 0;
    color: var(--text-light);
    font-size: 0.875rem;
    font-weight: 500;
}

/* =============================================
   TABULKY
   ============================================= */
.table-card {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    overflow: hidden;
    border: 1px solid var(--border-light);
}

.table-header {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.table-header h2 {
    margin: 0;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-dark);
}

.table {
    margin: 0;
}

.table thead th {
    background-color: var(--bg-light);
    border-bottom: 2px solid var(--border-color);
    color: var(--text-dark);
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.5px;
    padding: 1rem;
}

.table tbody td {
    padding: 1rem;
    vertical-align: middle;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-medium);
}

.table tbody tr:last-child td {
    border-bottom: none;
}

.table tbody tr:hover {
    background-color: rgba(37, 99, 235, 0.02);
}

/* =============================================
   BADGE (Stavové štítky)
   ============================================= */
.badge {
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-sm);
    font-weight: 600;
    font-size: 0.75rem;
    display: inline-block;
}

.badge-vystavena {
    background-color: rgba(59, 130, 246, 0.1);
    color: #2563eb;
}

.badge-zaplacena {
    background-color: rgba(16, 185, 129, 0.1);
    color: #10b981;
}

.badge-po-splatnosti {
    background-color: rgba(239, 68, 68, 0.1);
    color: #ef4444;
}

.badge-stornovana {
    background-color: rgba(107, 114, 128, 0.1);
    color: #6b7280;
}

.badge-nevystavena {
    background-color: rgba(156, 163, 175, 0.1);
    color: #6b7280;
}

/* =============================================
   PRÁZDNÝ STAV (Empty State)
   ============================================= */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
}

.empty-state i {
    font-size: 4rem;
    color: var(--border-color);
    margin-bottom: 1rem;
}

.empty-state h3 {
    color: var(--text-dark);
    margin-bottom: 0.5rem;
    font-size: 1.5rem;
}

.empty-state p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

/* =============================================
   HLAVNÍ OBSAH
   ============================================= */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 200px);
}

/* =============================================
   CARDS (Obecné karty)
   ============================================= */
.card-custom {
    background: var(--bg-white);
    border-radius: var(--radius-lg);
    padding: 2rem;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--border-light);
    margin-bottom: 1.5rem;
}

.card-custom h3 {
    margin-top: 0;
    margin-bottom: 1.5rem;
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
}

/* =============================================
   RESPONSIVITA
   ============================================= */
@media (max-width: 768px) {
    .table-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .stats-card {
        margin-bottom: 1rem;
    }
    
    .main-content {
        padding: 1rem 0;
    }
    
    .login-container {
        margin: 1rem;
    }
}

/* =============================================
   UTILITY CLASSES
   ============================================= */
.text-muted {
    color: var(--text-light) !important;
}

.text-small {
    font-size: 0.875rem;
}

.text-bold {
    font-weight: 600;
}

.mt-4 {
    margin-top: 1.5rem;
}

.mb-4 {
    margin-bottom: 1.5rem;
}

/* =============================================
   LOADING SPINNER
   ============================================= */
.spinner {
    border: 3px solid var(--border-color);
    border-top-color: var(--primary-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 0.8s linear infinite;
    margin: 2rem auto;
}

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