:root {
    /* Day Mode */
    --primary-color: #333333;
    --sidebar-bg: #f8f9fa;
    --accent-color: #6c757d;
    --success-color: #28a745;
    --danger-color: #dc3545;
    --bg-color: #ffffff;
    --card-bg: #ffffff;
    --text-color: #212529;
    --muted-color: #6c757d;
    --border-color: #dee2e6;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --border-radius: 12px;
    --sidebar-width: 280px;
}

[data-theme="dark"] {
    /* Dark Mode */
    --primary-color: #f8f9fa;
    --sidebar-bg: #1a1b1e;
    --accent-color: #adb5bd;
    --success-color: #2ecc71;
    --danger-color: #e74c3c;
    --bg-color: #141517;
    --card-bg: #25262b;
    --text-color: #e9ecef;
    --muted-color: #909296;
    --border-color: #373a40;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.3), 0 2px 4px -1px rgba(0, 0, 0, 0.2);
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: 'Inter', system-ui, -apple-system, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    font-size: 16px;
    display: flex;
    min-height: 100vh;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Sidebar Layout */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--sidebar-bg);
    border-right: 1px solid var(--border-color);
    padding: 2rem 1.5rem;
    position: fixed;
    height: 100vh;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    z-index: 2000;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.main-content {
    flex-grow: 1;
    margin-left: var(--sidebar-width);
    padding: 2.5rem;
    min-width: 0;
    width: 100%;
}

/* Mobile Header */
.mobile-header {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 60px;
    background-color: var(--card-bg);
    border-bottom: 1px solid var(--border-color);
    align-items: center;
    justify-content: space-between;
    padding: 0 1rem;
    z-index: 1001; /* Must be below sidebar (2000) */
    box-shadow: var(--shadow);
}

.hamburger {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px;
}

/* Theme Toggle */
.theme-toggle-btn {
    background: none;
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    color: var(--text-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.theme-toggle-btn:hover {
    background-color: var(--border-color);
}

/* Branding */
.logo {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 2.5rem;
    color: var(--primary-color);
    text-transform: uppercase;
    letter-spacing: 1px;
    line-height: 1.2;
}

/* Sidebar Nav */
.nav-links {
    list-style: none;
    margin-bottom: auto;
}

.nav-links li {
    margin-bottom: 0.5rem;
}

.nav-links a {
    color: var(--muted-color);
    text-decoration: none;
    font-weight: 500;
    padding: 10px 16px;
    border-radius: var(--border-radius);
    display: block;
    transition: all 0.2s;
}

.nav-links a:hover, .nav-links a.active {
    background-color: var(--border-color);
    color: var(--primary-color);
}

.nav-links a.btn-download {
    background-color: #333;
    color: white;
    margin-top: 1.5rem;
    text-align: center;
}

[data-theme="dark"] .nav-links a.btn-download {
    background-color: #fff;
    color: #000;
}

/* Cards & Content */
.card {
    background: var(--card-bg);
    border-radius: var(--border-radius);
    padding: 1.5rem;
    margin-bottom: 2rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

h1 {
    font-size: 2rem;
    margin-bottom: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

h2 {
    font-size: 1.4rem;
    margin-bottom: 1.5rem;
    font-weight: 600;
    color: var(--primary-color);
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

/* Tables */
.table-container {
    overflow-x: auto;
    margin-top: 1rem;
    border-radius: var(--border-radius);
}

table {
    width: 100%;
    border-collapse: collapse;
}

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

th {
    background-color: var(--sidebar-bg);
    font-weight: 600;
    color: var(--muted-color);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 1px;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 20px;
    border-radius: var(--border-radius);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
    transition: all 0.2s;
    font-size: 0.95rem;
    color: var(--text-color);
}

.btn:hover {
    background: var(--border-color);
}

.btn-primary {
    background-color: #333;
    color: white;
    border-color: #333;
}

[data-theme="dark"] .btn-primary {
    background-color: #fff;
    color: #000;
    border-color: #fff;
}

.form-group {
    margin-bottom: 1.25rem;
    width: 100%;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--muted-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input[type="text"],
input[type="password"],
input[type="email"],
select,
textarea {
    width: 100%;
    padding: 12px 16px;
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    background-color: var(--card-bg);
    color: var(--text-color);
    font-family: inherit;
    font-size: 1rem;
    transition: all 0.2s ease;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(51, 51, 51, 0.1);
}

[data-theme="dark"] input:focus, 
[data-theme="dark"] select:focus, 
[data-theme="dark"] textarea:focus {
    box-shadow: 0 0 0 3px rgba(248, 249, 250, 0.1);
}

.btn-toggle {
    display: flex;
    margin-bottom: 2rem;
    background: var(--sidebar-bg);
    padding: 4px;
    border-radius: var(--border-radius);
    width: fit-content;
}

.btn-toggle .btn {
    border: none;
    background: transparent;
    border-radius: calc(var(--border-radius) - 4px);
    font-size: 0.9rem;
}

.btn-toggle .btn.active {
    background: var(--card-bg);
    box-shadow: var(--shadow);
    color: var(--primary-color);
}

/* Drop Zone */
.drop-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--border-radius);
    padding: 3rem 2rem;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
    background-color: var(--sidebar-bg);
    margin-bottom: 1.5rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.drop-zone:hover, .drop-zone.dragover {
    border-color: var(--success-color);
    background-color: rgba(40, 167, 69, 0.05);
}

.drop-zone__icon {
    color: var(--muted-color);
    transition: color 0.2s;
}

.drop-zone:hover .drop-zone__icon, .drop-zone.dragover .drop-zone__icon {
    color: var(--success-color);
}

.drop-zone__input {
    display: none;
}

.drop-zone__text {
    font-weight: 500;
    color: var(--text-color);
}

.drop-zone__subtext {
    font-size: 0.85rem;
    color: var(--muted-color);
}

.mobile-only {
    display: none !important;
}

.close-btn-container {
    display: flex;
    justify-content: flex-end;
    padding: 1rem 1rem 0 0;
}

.close-btn {
    background: var(--border-color);
    border: none;
    cursor: pointer;
    color: var(--text-color);
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Responsive Overhaul - Strictly Screen Only to avoid leaking into Print */
@media screen and (max-width: 991px) {
    body {
        flex-direction: column;
        padding-top: 60px; /* Space for mobile header */
    }

    .mobile-header {
        display: flex;
    }

    .mobile-only {
        display: flex !important;
    }

    .sidebar {
        transform: translateX(-100%);
        width: min(300px, 85vw);
        box-shadow: 10px 0 30px rgba(0,0,0,0.1);
    }

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

    .sidebar-overlay {
        display: none;
        position: fixed;
        inset: 0;
        background: rgba(0,0,0,0.6);
        z-index: 1999;
        backdrop-filter: blur(4px);
    }

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

    .main-content {
        margin-left: 0;
        padding: 1.5rem 1rem;
    }

    h1 { font-size: 1.6rem; }

    /* Header Controls */
    .header-controls {
        display: grid !important;
        grid-template-columns: 1fr 1fr; /* Strict 2 columns */
        gap: 0.75rem !important;
        width: 100%;
    }

    .header-controls #btn-print {
        grid-column: span 2;
        width: 100%;
        margin-bottom: 0.5rem;
    }

    .header-controls > div {
        width: 100% !important;
        margin: 0 !important;
    }

    .header-controls select {
        width: 100% !important; /* Force full width within grid cell */
    }

    .btn-toggle {
        width: 100%;
    }

    .btn-toggle .btn {
        flex: 1;
    }

    /* Table to Card Conversion - ONLY for the main UI table, NOT the print table */
    #agenda-table, #agenda-table thead, #agenda-table tbody, #agenda-table th, #agenda-table td, #agenda-table tr {
        display: block;
    }

    thead tr {
        position: absolute;
        top: -9999px;
        left: -9999px;
    }

    .activity-row {
        border: 1px solid var(--border-color);
        border-radius: var(--border-radius);
        margin-bottom: 1.5rem;
        padding: 0.5rem;
        background: var(--card-bg);
    }

    #agenda-table td {
        border: none;
        border-bottom: 1px solid var(--border-color);
        position: relative;
        padding-left: 50% !important;
        text-align: right !important;
        min-height: 50px;
        display: flex;
        align-items: center;
        justify-content: flex-end;
    }

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

    #agenda-table td::before {
        position: absolute;
        left: 1rem;
        width: 45%;
        padding-right: 10px;
        white-space: nowrap;
        text-align: left;
        font-weight: 700;
        color: var(--muted-color);
        content: attr(data-label);
        font-size: 0.8rem;
        text-transform: uppercase;
    }
}

/* FullCalendar Fixes */
.fc {
    background: var(--card-bg) !important;
    color: var(--text-color) !important;
}

.fc-theme-standard td, .fc-theme-standard th {
    border-color: var(--border-color) !important;
}

/* Mobile Calendar Adjustments */
@media (max-width: 767px) {
    .fc .fc-toolbar {
        flex-direction: column;
        gap: 0.5rem;
    }
    .fc .fc-toolbar-title {
        font-size: 1.1rem !important;
    }
}

/* Print Mode */
@media print {
    @page {
        margin: 1.5cm;
    }
    
    .mobile-header, .sidebar, .theme-toggle-btn, #btn-print, .sidebar-overlay, .no-print, .alert, .btn-toggle {
        display: none !important;
    }
    
    .main-content { 
        display: block !important;
    }
    
    body, html {
        display: block !important;
        height: auto !important;
        min-height: auto !important;
        background-color: white !important;
        color: black !important;
    }
    
    .card {
        box-shadow: none !important;
        border: none !important;
        padding: 0 !important;
        margin: 0 !important;
    }
    
    #list-view, #calendar-view, #changes-view { display: none !important; }

    .print-only { display: block !important; }
    
    /* Absolute reset for the print table to force one-line-per-activity */
    .print-only table {
        display: table !important;
        width: 100% !important;
    }
    .print-only tr {
        display: table-row !important;
    }
    .print-only td, .print-only th {
        display: table-cell !important;
        text-align: left !important;
        padding: 8px !important;
        vertical-align: top !important;
    }
}

.print-only { display: none; }