:root {
    /* Color Palette */
    --primary: #4F46E5;
    --primary-hover: #4338CA;
    --primary-light: #EEF2FF;
    --secondary: #10B981;
    --secondary-hover: #059669;
    --danger: #EF4444;
    --danger-hover: #DC2626;
    --danger-light: #FEF2F2;
    --warning: #F59E0B;
    --background: #F8FAFC;
    --surface: #FFFFFF;
    --text-main: #0F172A;
    --text-muted: #64748B;
    --border: #E2E8F0;

    /* Shadows & Effects */
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --glass-bg: rgba(255, 255, 255, 0.8);
    --glass-border: rgba(255, 255, 255, 0.3);
    
    /* Layout */
    --radius: 0.75rem;
    --radius-sm: 0.375rem;
    --radius-lg: 1rem;
    --transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Outfit', sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.5;
    min-height: 100vh;
}

/* App Shell Layout */
#app {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

header {
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 50;
    box-shadow: var(--shadow-sm);
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

nav {
    display: flex;
    gap: 1rem;
}

main {
    flex: 1;
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
    width: 100%;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    color: var(--text-main);
}

h1 { font-size: 2.25rem; margin-bottom: 1.5rem; }
h2 { font-size: 1.5rem; margin-bottom: 1rem; }
p { color: var(--text-muted); }

/* Components */
.card {
    background: var(--surface);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    padding: 1.5rem;
    border: 1px solid var(--border);
    transition: var(--transition);
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem 1rem;
    border-radius: var(--radius);
    font-weight: 500;
    font-family: inherit;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
    gap: 0.5rem;
}

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

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-sm);
}

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

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

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

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

.badge {
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.875rem;
    font-weight: 500;
}

.badge-primary { background: var(--primary-light); color: var(--primary); }
.badge-danger { background: var(--danger-light); color: var(--danger); }

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: var(--text-main);
    font-size: 0.875rem;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-family: inherit;
    transition: var(--transition);
    background: var(--surface);
    color: var(--text-main);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-light);
}

/* Calendar Grid */
.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, 1fr);
    gap: 0.5rem;
    margin-top: 1rem;
}

/* Calendar with week-number column: [wk#] [Sun] [Mon] [Tue] [Wed] [Thu] [Fri] [Sat] */
.calendar-grid-with-weeks {
    display: grid;
    grid-template-columns: 2.25rem repeat(7, 1fr);
    gap: 0.5rem;
    margin-top: 1rem;
}

.calendar-week-label {
    aspect-ratio: 1;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--background);
    color: var(--text-muted);
    font-size: 0.7rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: var(--transition);
    user-select: none;
}

.calendar-week-label:hover {
    border-color: var(--primary);
    color: var(--primary);
    background: var(--primary-light);
}

.calendar-week-label.selected {
    background: var(--primary);
    color: white;
    border-color: var(--primary);
}

.calendar-header {
    text-align: center;
    font-weight: 600;
    color: var(--text-muted);
    padding: 0.5rem;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.calendar-day {
    aspect-ratio: 1;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.5rem;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    cursor: pointer;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.calendar-day:hover:not(.empty) {
    border-color: var(--primary);
    box-shadow: var(--shadow-sm);
    z-index: 10;
}

.calendar-day.empty {
    background: transparent;
    border-color: transparent;
    cursor: default;
}

.calendar-day.selected {
    border-color: var(--primary) !important;
    box-shadow: 0 0 0 2px var(--primary), var(--shadow-md) !important;
    background-color: rgba(79, 70, 229, 0.12) !important;
    z-index: 5;
    animation: selection-flash 0.35s cubic-bezier(0.25, 0.8, 0.25, 1);
}

@keyframes selection-flash {
    0% {
        background-color: var(--warning) !important;
        transform: scale(0.95);
    }
    50% {
        background-color: var(--warning) !important;
        transform: scale(1.02);
    }
    100% {
        transform: scale(1);
    }
}

.calendar-day.unavailable {
    background-color: var(--danger-light);
    border-color: var(--danger);
}

.calendar-day.has-shift {
    background-color: var(--primary-light);
    border-color: var(--primary);
}

.day-number {
    font-weight: 500;
    margin-bottom: auto;
}

.day-content {
    font-size: 0.75rem;
    color: var(--text-muted);
    text-align: center;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.animate-fade-in {
    animation: fadeIn 0.4s ease-out forwards;
}

/* Modals/Overlays */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(15, 23, 42, 0.5);
    backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 100;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.overlay.active {
    opacity: 1;
    pointer-events: auto;
}

.modal {
    background: var(--surface);
    border-radius: var(--radius-lg);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    padding: 2rem;
    box-shadow: var(--shadow-lg);
    transform: scale(0.95);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.overlay.active .modal {
    transform: scale(1);
}

/* Utility classes */
.flex { display: flex; }
.flex-col { display: flex; flex-direction: column; }
.justify-between { justify-content: space-between; }
.items-center { align-items: center; }
.gap-2 { gap: 0.5rem; }
.gap-4 { gap: 1rem; }
.mt-4 { margin-top: 1rem; }
.mb-4 { margin-bottom: 1rem; }
.w-full { width: 100%; }
.text-center { text-align: center; }
.text-danger { color: var(--danger); }
.text-primary { color: var(--primary); }
.hidden { display: none !important; }

/* Table */
.table-container {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border);
    background: var(--surface);
}

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

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

th {
    background-color: var(--background);
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

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

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

/* Wide view for composite availability */
main.wide-view {
    max-width: 100% !important;
    padding: 1rem !important;
}

/* Unavailability reason text in calendar */
.day-reason {
    font-size: 0.6rem;
    color: var(--danger);
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    max-width: 100%;
    padding: 0 2px;
    line-height: 1.1;
    margin-top: 2px;
    font-style: italic;
}

/* Header nav responsive */
header nav {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
    align-items: center;
}

/* Tab Containers */
.admin-tab-container, .resident-tab-container {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    flex-wrap: wrap;
}

/* Card Header Flex Layout */
.card-header-flex {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1.5rem;
}

/* Mobile responsive styles */
.calendar-scroll-container {
    width: 100%;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    margin-top: 1rem;
    border-radius: var(--radius);
    border: 1px solid var(--border);
    background: var(--surface);
    padding: 0.5rem;
}

/* Clean scrollbar for calendar horizontal scrolling */
.calendar-scroll-container::-webkit-scrollbar {
    height: 6px;
}
.calendar-scroll-container::-webkit-scrollbar-track {
    background: var(--background);
    border-radius: 3px;
}
.calendar-scroll-container::-webkit-scrollbar-thumb {
    background: #CBD5E1;
    border-radius: 3px;
}
.calendar-scroll-container::-webkit-scrollbar-thumb:hover {
    background: #94A3B8;
}

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

@media (max-width: 768px) {
    header {
        padding: 1rem;
        flex-direction: column;
        gap: 0.75rem;
        align-items: center;
    }
    
    header nav {
        display: flex;
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.35rem;
        width: 100%;
    }

    header nav .btn {
        padding: 0.35rem 0.75rem;
        font-size: 0.8rem;
        flex: 1 1 auto;
    }

    header nav .flex {
        width: 100%;
        justify-content: center;
        margin-bottom: 0.5rem;
        margin-right: 0 !important;
        flex-wrap: wrap;
        gap: 0.5rem;
    }
    
    main {
        padding: 1rem 0.5rem;
    }
    
    .mobile-only {
        display: block !important;
    }
    
    .calendar-grid {
        min-width: 600px;
    }
    
    .calendar-grid-with-weeks {
        min-width: 680px;
    }
    
    .calendar-action-bar {
        flex-direction: column;
        align-items: stretch;
        gap: 0.75rem;
    }
    
    .calendar-action-bar > span {
        text-align: center;
    }
    
    .calendar-action-bar > .flex {
        flex-direction: column;
        width: 100%;
        gap: 0.5rem;
    }

    .calendar-action-bar > .flex > .btn {
        width: 100%;
        margin-bottom: 0.25rem;
    }

    /* Vertical stacked tabs for mobile per user preference */
    .admin-tab-container, .resident-tab-container {
        flex-direction: column;
        align-items: stretch;
        gap: 0.35rem;
    }

    .admin-tab-container .btn, .resident-tab-container .btn {
        width: 100%;
    }

    /* Stacking Quick Block panel elements */
    .quick-block-container {
        flex-direction: column;
        align-items: stretch !important;
        gap: 0.75rem !important;
    }

    .quick-block-container #quick-block-type,
    .quick-block-container #quick-block-reason,
    .quick-block-container .btn {
        width: 100% !important;
    }

    /* Card Header Flex Column Layout */
    .card-header-flex {
        flex-direction: column;
        align-items: stretch;
    }
    .card-header-flex h2 {
        text-align: center;
    }
    .card-header-flex > .flex {
        flex-wrap: wrap;
        justify-content: center;
        width: 100%;
        gap: 0.5rem;
    }
    .card-header-flex > .flex > .btn {
        flex: 1 1 calc(50% - 0.25rem);
        font-size: 0.85rem;
        padding: 0.5rem;
    }
}

/* Attending & Doctor of the Day compact styles */
.calendar-day-dod {
    aspect-ratio: auto;
    min-height: 135px;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.4rem;
    display: flex;
    flex-direction: column;
    background: var(--surface);
    transition: var(--transition);
}

.dod-select-group {
    display: flex;
    flex-direction: column;
    gap: 4px;
    margin-top: auto;
    width: 100%;
}

.dod-select-row {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.7rem;
}

.dod-select-row label {
    font-weight: 600;
    color: var(--text-muted);
    min-width: 12px;
}

.dod-select-control {
    flex: 1;
    font-size: 0.7rem;
    padding: 2px;
    border: 1px solid var(--border);
    border-radius: 4px;
    background: var(--surface);
    color: var(--text-main);
    outline: none;
    cursor: pointer;
    font-family: inherit;
    max-width: 100%;
}

.dod-select-control:focus {
    border-color: var(--primary);
}