/* CSS Variables for Theming */
:root {
    /* Light Theme (Default) */
    --bg-body: #f4f5f7;
    --bg-surface: #ffffff;
    --bg-surface-hover: #f9fafb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --border-color: #e5e7eb;
    --brand-gradient: linear-gradient(135deg, #4f46e5, #ec4899);
    --brand-gradient-hover: linear-gradient(135deg, #4338ca, #db2777);
    --accent-color: #4f46e5;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --danger-color: #ef4444;
    --danger-hover: #dc2626;
    --success-color: #10b981;
}

[data-theme="dark"] {
    /* Dark Theme */
    --bg-body: #0d0e12;
    --bg-surface: #16181d;
    --bg-surface-hover: #1f2229;
    --text-primary: #f9fafb;
    --text-secondary: #9ca3af;
    --border-color: #2d3139;
    --brand-gradient: linear-gradient(135deg, #6366f1, #a855f7, #ec4899);
    --brand-gradient-hover: linear-gradient(135deg, #4f46e5, #9333ea, #db2777);
    --accent-color: #8b5cf6;
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.5);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.5);
    --danger-color: #ef4444;
    --danger-hover: #f87171;
    --success-color: #10b981;
}

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

html {
    scrollbar-gutter: stable;
    /* Prevents layout shift when scrollbars appear */
}

body {
    background-color: var(--bg-body);
    color: var(--text-primary);
    min-height: 100vh;
    width: 100%;
    /* Changed from 100vw to prevent horizontal scrollbar issues */
    overflow-x: hidden;
    transition: background-color 0.3s ease, color 0.3s ease;
    font-family: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Custom Scrollbars for Modern App Feel */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

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

::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 10px;
}

::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-secondary);
}

/* Global Accessibility Focus Ring */
:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
    border-radius: 4px;
}

/* Base utility elements */
a {
    color: var(--accent-color);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.flex {
    display: flex;
}

.flex-col {
    flex-direction: column;
}

.items-center {
    align-items: center;
}

.justify-between {
    justify-content: space-between;
}

.justify-center {
    justify-content: center;
}

.justify-end {
    justify-content: flex-end;
}

.gap-2 {
    gap: 8px;
}

.gap-4 {
    gap: 16px;
}

.gap-6 {
    gap: 24px;
}

.mt-2 {
    margin-top: 8px;
}

.mt-4 {
    margin-top: 16px;
}

.mt-6 {
    margin-top: 24px;
}

.mb-2 {
    margin-bottom: 8px;
}

.mb-4 {
    margin-bottom: 16px;
}

.mb-6 {
    margin-bottom: 24px;
}

.w-full {
    width: 100%;
}

.text-center {
    text-align: center;
}

.hidden {
    display: none !important;
}

/* SVG Icon Base */
svg.lucide,
.nav-item svg,
.icon-btn svg {
    width: 20px;
    height: 20px;
    stroke: currentColor;
    stroke-width: 2;
    stroke-linecap: round;
    stroke-linejoin: round;
    fill: none;
    flex-shrink: 0;
    /* Prevents icon squishing */
}

/* Layout Wrapper for Dashboard */
.dashboard-wrapper {
    display: flex;
    width: 100%;
    height: 100vh;
    opacity: 0;
    transition: opacity 0.4s ease-in-out;
}

.dashboard-wrapper.visible {
    opacity: 1;
}

/* Sidebar Layout */
.sidebar {
    width: 260px;
    height: 100%;
    background-color: var(--bg-surface);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), background-color 0.3s ease;
    z-index: 100;
    flex-shrink: 0;
}

.brand {
    height: 70px;
    display: flex;
    align-items: center;
    padding: 0 24px;
    font-size: 1.25rem;
    font-weight: 700;
    border-bottom: 1px solid var(--border-color);
    gap: 12px;
    user-select: none;
}

.brand-logo {
    width: 28px;
    height: 28px;
    background: var(--brand-gradient);
    border-radius: 6px;
    box-shadow: var(--shadow-sm);
}

.nav-links {
    flex: 1;
    padding: 24px 16px;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.nav-item {
    display: flex;
    align-items: center;
    padding: 10px 16px;
    color: var(--text-secondary);
    text-decoration: none;
    border-radius: 8px;
    gap: 12px;
    font-weight: 500;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    border: none;
    background: transparent;
    width: 100%;
    text-align: left;
    user-select: none;
}

.nav-item:hover,
.nav-item.active {
    background-color: var(--bg-surface-hover);
    color: var(--text-primary);
}

.nav-item:active {
    transform: scale(0.98);
}

.nav-item.active {
    position: relative;
    font-weight: 600;
}

.nav-item.active::before {
    content: '';
    position: absolute;
    left: -16px;
    top: 50%;
    transform: translateY(-50%);
    height: 60%;
    width: 4px;
    background-color: var(--accent-color);
    border-radius: 0 4px 4px 0;
}

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

/* Main App Area */
.app-main {
    flex: 1;
    height: 100%;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

/* Header */
.header {
    height: 70px;
    background-color: var(--bg-body);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    flex-shrink: 0;
    transition: background-color 0.3s ease;
}

.menu-toggle {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
    margin-left: -8px;
    border-radius: 8px;
}

.menu-toggle:hover {
    background-color: var(--bg-surface-hover);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-left: auto;
}

.icon-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    align-items: center;
    justify-content: center;
}

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

.icon-btn:active {
    transform: scale(0.95);
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    background-color: var(--bg-surface);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    user-select: none;
}

.btn:hover {
    background-color: var(--bg-surface-hover);
    box-shadow: var(--shadow-sm);
}

.btn:active {
    transform: scale(0.98);
}

.btn-primary {
    background: var(--brand-gradient);
    color: #ffffff;
    border: none;
    box-shadow: var(--shadow-sm);
}

.btn-primary:hover {
    background: var(--brand-gradient-hover);
    color: #ffffff;
    box-shadow: var(--shadow-md);
}

.btn-danger {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.btn-danger:hover {
    background: rgba(239, 68, 68, 0.15);
    color: var(--danger-hover);
    border-color: rgba(239, 68, 68, 0.3);
}

/* Scrollable Content Area */
.content-scroll {
    flex: 1;
    overflow-y: auto;
    padding: 32px;
    scroll-behavior: smooth;
}

.page-title {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 8px;
    letter-spacing: -0.02em;
    color: var(--text-primary);
}

.page-subtitle {
    color: var(--text-secondary);
    margin-bottom: 32px;
    font-size: 1rem;
}

/* Dashboard Grid */
.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 24px;
}

.card {
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 24px;
    box-shadow: var(--shadow-sm);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background-color 0.3s ease;
}

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

.card-wide {
    grid-column: 1 / -1;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 8px;
}

.stat-value {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: baseline;
    gap: 12px;
    letter-spacing: -0.01em;
}

/* Tables */
.table-container {
    width: 100%;
    max-height: 600px;
    overflow: auto;
    /* Changed to auto to support sticky headers */
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: var(--shadow-sm);
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    white-space: nowrap;
}

th,
td {
    padding: 16px 24px;
    border-bottom: 1px solid var(--border-color);
}

th {
    background-color: var(--bg-surface);
    /* Matches container to prevent transparency overlapping */
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    position: sticky;
    top: 0;
    z-index: 10;
    box-shadow: 0 1px 0 var(--border-color);
    /* Fixes border collapse bug with sticky headers */
}

tr:hover td {
    background-color: var(--bg-surface-hover);
}

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

/* Forms */
.form-group {
    margin-bottom: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

label {
    font-weight: 500;
    font-size: 0.875rem;
    color: var(--text-secondary);
}

input,
select,
textarea {
    padding: 12px 16px;
    background-color: var(--bg-body);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.95rem;
    color: var(--text-primary);
    outline: none;
    transition: all 0.2s ease;
    width: 100%;
}

input::placeholder,
textarea::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
}

input:focus,
select:focus,
textarea:focus {
    background-color: var(--bg-surface);
    border-color: var(--accent-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.15);
}

/* Auth Container */
.auth-container {
    max-width: 440px;
    width: 100%;
    margin: 10vh auto;
    padding: 32px;
    background-color: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    box-shadow: var(--shadow-md);
}

.auth-container.hidden-auth {
    opacity: 0;
    transform: translateY(10px);
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
}

.auth-container.visible-auth {
    opacity: 1;
    transform: translateY(0);
}

/* Alerts */
.alert {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 16px;
    font-size: 0.9rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 8px;
}

.alert-error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--danger-color);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success-color);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

/* Status Badges */
.badge {
    padding: 4px 10px;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
    display: inline-flex;
    align-items: center;
    letter-spacing: 0.025em;
    text-transform: uppercase;
}

/* Landing Page Additions */
.hero {
    text-align: center;
    padding: 80px 24px;
    max-width: 800px;
    margin: 0 auto;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
    padding: 40px 24px;
    max-width: 1200px;
    margin: 0 auto;
}

/* Mobile Overlay */
.mobile-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100vh;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 50;
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.mobile-overlay.active {
    display: block;
    opacity: 1;
}

/* Responsive Design */
@media (max-width: 768px) {
    .sidebar {
        position: fixed;
        left: 0;
        top: 0;
        transform: translateX(-100%);
        box-shadow: var(--shadow-md);
        /* Adds depth over the main content */
    }

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

    .menu-toggle {
        display: block;
    }

    .header {
        padding: 0 20px;
    }

    .content-scroll {
        padding: 20px;
    }

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

    .stat-value {
        font-size: 1.75rem;
    }
}