/* ===== CSS Variables für Light/Dark Mode ===== */
:root[data-theme="light"] {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-sidebar: #1a1d29;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --text-sidebar: #e0e0e0;
    --border-color: #dee2e6;
    --card-shadow: 0 2px 4px rgba(0,0,0,0.1);
    --sidebar-hover: #252a3a;
    --sidebar-active: #667eea;
}

:root[data-theme="dark"] {
    --bg-primary: #1a1d29;
    --bg-secondary: #252a3a;
    --bg-sidebar: #0f1117;
    --text-primary: #e0e0e0;
    --text-secondary: #9ca3af;
    --text-sidebar: #e0e0e0;
    --border-color: #3a3f52;
    --card-shadow: 0 2px 8px rgba(0,0,0,0.4);
    --sidebar-hover: #1a1d29;
    --sidebar-active: #667eea;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* ===== Sidebar ===== */
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 280px;
    height: 100vh;
    background-color: var(--bg-sidebar);
    color: var(--text-sidebar);
    overflow-y: auto;
    transition: transform 0.3s ease;
    z-index: 1000;
    display: flex;
    flex-direction: column;
}

.sidebar::-webkit-scrollbar {
    width: 6px;
}

.sidebar::-webkit-scrollbar-track {
    background: transparent;
}

.sidebar::-webkit-scrollbar-thumb {
    background: rgba(255,255,255,0.2);
    border-radius: 3px;
}

.sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255,255,255,0.3);
}

/* ===== Sidebar Header ===== */
.sidebar-header {
    padding: 0;
    border-bottom: 1px solid rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    justify-content: space-between;
    position: relative;
}

.logo-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.sidebar-logo {
    max-width: 100%;
    height: auto;
}

.logo-text {
    font-size: 18px;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.sidebar-close {
    display: none;
    background: transparent;
    border: none;
    color: var(--text-sidebar);
    font-size: 20px;
    cursor: pointer;
    padding: 5px;
}

/* ===== Sidebar Navigation ===== */
.sidebar-nav {
    flex: 1;
    padding: 10px 10px 20px 10px;
    overflow-y: auto;
}

.sidebar-section {
    margin-bottom: 12px;
}

.sidebar-section-title {
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: rgba(255,255,255,0.5);
    padding: 0 10px 5px;
    margin-bottom: 2px;
}

.sidebar-link {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 7px 10px 7px 12px;
    color: var(--text-sidebar);
    text-decoration: none;
    border-radius: 6px;
    margin-bottom: 1px;
    transition: all 0.2s ease;
    font-size: 13px;
    border-left: 3px solid transparent;
}

.sidebar-link:hover {
    background-color: rgba(255,255,255,0.07);
    color: #ffffff;
    border-left-color: rgba(102,126,234,0.6);
}

.sidebar-link.active {
    background-color: rgba(102,126,234,0.18);
    color: #a78bfa;
    border-left-color: #a78bfa;
    font-weight: 600;
}

.sidebar-link i {
    font-size: 15px;
    width: 18px;
    text-align: center;
}

.sidebar-submenu {
    padding-left: 22px;
    margin-top: 2px;
}

.sidebar-sublink {
    display: block;
    padding: 5px 10px;
    color: rgba(255,255,255,0.7);
    text-decoration: none;
    font-size: 12px;
    border-radius: 5px;
    margin-bottom: 1px;
    transition: all 0.2s ease;
}

.sidebar-sublink:hover {
    background-color: var(--sidebar-hover);
    color: #ffffff;
    padding-left: 14px;
}

.dropdown-toggle i.bi-chevron-down {
    font-size: 12px;
    transition: transform 0.2s ease;
}

.dropdown-toggle[aria-expanded="true"] i.bi-chevron-down {
    transform: rotate(180deg);
}

/* ===== Sidebar Footer ===== */
.sidebar-footer {
    padding: 12px 10px;
    border-top: 1px solid rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    gap: 4px;
    background-color: rgba(0,0,0,0.2);
    overflow: hidden;
}

.sidebar-icon-group {
    display: flex;
    align-items: center;
    gap: 0;
    flex-shrink: 0;
}

.theme-toggle,
.logout-btn {
    background: transparent;
    border: none;
    color: var(--text-sidebar);
    font-size: 16px;
    cursor: pointer;
    padding: 6px;
    border-radius: 6px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 8px;
    flex: 1;
    min-width: 0;
    font-size: 13px;
    color: var(--text-sidebar);
    overflow: hidden;
}

.user-info i {
    font-size: 18px;
    flex-shrink: 0;
}

.user-info div {
    overflow: hidden;
}

.user-info .fw-bold,
.user-info small {
    display: block;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.theme-toggle:hover,
.logout-btn:hover {
    background-color: var(--sidebar-hover);
    color: #ffffff;
}

/* ===== Mobile Header ===== */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background-color: var(--bg-sidebar);
    color: var(--text-sidebar);
    padding: 0 15px;
    align-items: center;
    justify-content: space-between;
    z-index: 999;
    box-shadow: 0 2px 10px rgba(0,0,0,0.2);
}

.sidebar-toggle,
.theme-toggle-mobile {
    background: transparent;
    border: none;
    color: var(--text-sidebar);
    font-size: 24px;
    cursor: pointer;
    padding: 8px;
}

.mobile-logo {
    font-size: 18px;
    font-weight: 700;
}

/* ===== Sidebar Overlay ===== */
.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0,0,0,0.5);
    z-index: 999;
}

.sidebar-overlay.active {
    display: block;
}

/* ===== Main Content ===== */
.main-content {
    margin-left: 280px;
    min-height: 100vh;
    transition: margin-left 0.3s ease;
}

.content-wrapper {
    padding: 30px;
    max-width: 1400px;
}

/* ===== Cards ===== */
.card {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
    margin-bottom: 20px;
    border-radius: 10px;
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

.card-body {
    padding: 20px;
}

.card-header {
    background-color: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 15px 20px;
}

/* ===== Tables ===== */
.table {
    color: var(--text-primary);
}

.table thead {
    background-color: var(--bg-secondary);
    border-bottom: 2px solid var(--border-color);
}

.table tbody tr {
    border-bottom: 1px solid var(--border-color);
}

.table tbody tr:hover {
    background-color: var(--bg-secondary);
}

/* ===== Forms ===== */
.form-control,
.form-select {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    transition: all 0.2s ease;
}

.form-control:focus,
.form-select:focus {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

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

/* ===== Buttons ===== */
.btn {
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.2s ease;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border: none;
}

.btn-primary:hover {
    background: linear-gradient(135deg, #5568d3 0%, #63408a 100%);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

/* ===== Page Header ===== */
.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid var(--border-color);
}

.page-header h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.header-actions {
    display: flex;
    gap: 10px;
}

/* ===== Status Badges ===== */
.status-badge {
    padding: 5px 10px;
    border-radius: 4px;
    font-size: 0.875rem;
}

.status-offen {
    background-color: #ffc107;
    color: #000;
}

.status-bezahlt {
    background-color: #28a745;
    color: #fff;
}

.status-mahnung {
    background-color: #dc3545;
    color: #fff;
}

.status-storniert {
    background-color: #6c757d;
    color: #fff;
}

/* ===== Login Container ===== */
.login-container {
    max-width: 400px;
    margin: 100px auto;
}

.form-required {
    color: #dc3545;
}

/* ===== Responsive Design ===== */
@media (max-width: 992px) {
    .sidebar {
        transform: translateX(-100%);
    }

    .sidebar.active {
        transform: translateX(0);
    }

    .sidebar-close {
        display: block;
    }

    .mobile-header {
        display: flex;
    }

    .main-content {
        margin-left: 0;
        padding-top: 60px;
    }

    .content-wrapper {
        padding: 20px 15px;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 15px;
    }

    .header-actions {
        width: 100%;
        flex-wrap: wrap;
    }
}

@media (max-width: 576px) {
    .content-wrapper {
        padding: 15px 10px;
    }

    .page-header h1 {
        font-size: 22px;
    }

    .card-body {
        padding: 15px;
    }

    .table {
        font-size: 13px;
    }

    .btn {
        font-size: 13px;
        padding: 6px 12px;
    }
}

/* ===== Print Styles ===== */
@media print {
    .sidebar,
    .mobile-header,
    .sidebar-overlay {
        display: none !important;
    }

    .main-content {
        margin-left: 0 !important;
    }
}