@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700&display=swap');

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --text-main: #111827;
    --text-muted: #6b7280;
    --accent: #4f46e5;
    --accent-hover: #4338ca;
    --border-color: #e5e7eb;
    --card-shadow: 0 1px 3px rgba(0,0,0,0.08);
    --font-sans: 'Inter', sans-serif;
    --day-today: #f5f3ff;
    --event-pill-bg: #f3f4f6;
    --input-focus: #c7d2fe;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: #111827;
        --bg-secondary: #1f2937;
        --text-main: #f9fafb;
        --text-muted: #9ca3af;
        --border-color: #374151;
        --card-shadow: 0 1px 3px rgba(0,0,0,0.3);
        --day-today: #312e81;
        --event-pill-bg: #374151;
        --input-focus: #4338ca;
    }
}

* {
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    margin: 0;
    padding: 0;
}

body {
    font-family: var(--font-sans);
    background-color: var(--bg-primary);
    color: var(--text-main);
    line-height: 1.6;
    height: 100vh;
    display: flex;
}

.app-shell {
    display: grid;
    grid-template-columns: 350px 1fr;
    width: 100%;
    height: 100vh;
}

/* Sidebar Styling */
.sidebar {
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    padding: 32px;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
}

.brand {
    margin-bottom: 32px;
}

.brand h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-main);
}

.brand p {
    color: var(--text-muted);
    font-size: 0.875rem;
    margin-top: 4px;
}

.add-section {
    flex-grow: 1;
}

.glass-form .form-group {
    margin-bottom: 20px;
}

.glass-form label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 6px;
    color: var(--text-main);
}

.glass-form input,
.glass-form select,
.glass-form textarea {
    width: 100%;
    padding: 10px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    color: var(--text-main);
    transition: all 0.2s;
}

.glass-form input:focus,
.glass-form select:focus,
.glass-form textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--input-focus);
}

.days-checkbox-group {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 8px;
    background: var(--bg-primary);
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.75rem;
    font-weight: 400;
    cursor: pointer;
}

.checkbox-label input[type="checkbox"] {
    width: 16px;
    height: 16px;
    border-radius: 4px;
    border: 1px solid var(--border-color);
    cursor: pointer;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}

.primary-btn {
    width: 100%;
    padding: 12px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    font-size: 0.9375rem;
    cursor: pointer;
    transition: background 0.2s;
    margin-top: 8px;
}

.primary-btn:hover {
    background: var(--accent-hover);
}

.secondary-btn {
    width: 100%;
    padding: 10px;
    background: transparent;
    color: var(--text-muted);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-weight: 500;
    font-size: 0.875rem;
    cursor: pointer;
    transition: all 0.2s;
    margin-top: 16px;
}

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

/* Mobile Toggle */
.mobile-toggle {
    display: none;
    position: fixed;
    top: 16px;
    right: 16px;
    z-index: 2000;
    background: var(--accent);
    border: none;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    cursor: pointer;
}

.menu-icon, .menu-icon::before, .menu-icon::after {
    content: '';
    display: block;
    width: 18px;
    height: 2px;
    background: white;
    position: absolute;
    left: 11px;
    transition: all 0.2s;
}

.menu-icon { top: 19px; }
.menu-icon::before { top: -5px; left: 0; }
.menu-icon::after { top: 5px; left: 0; }

/* Calendar Container Styling */
.calendar-container {
    padding: 32px 48px;
    display: flex;
    flex-direction: column;
    height: 100vh;
    min-width: 0; /* Allow container to shrink below its content's size */
}

.calendar-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
    flex-shrink: 0;
}

.current-month-display h2 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
}

.calendar-nav {
    display: flex;
    align-items: center;
    gap: 8px;
}

.nav-btn {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    font-size: 0.875rem;
    color: var(--text-main);
    transition: all 0.2s;
}

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

.today-btn {
    font-weight: 600;
    padding-left: 16px;
    padding-right: 16px;
}

/* Calendar Grid Wrapper */
.calendar-grid-wrapper {
    flex-grow: 1;
    overflow-x: auto;
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
    width: 100%;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--border-color); /* Color for the grid lines */
    display: flex;
    flex-direction: column;
}

.calendar-weekdays {
    display: grid;
    grid-template-columns: repeat(7, minmax(120px, 1fr));
    text-align: center;
    background: var(--bg-secondary);
    padding: 12px 0;
    font-weight: 600;
    color: var(--text-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    min-width: 840px; /* 7 * 120px */
    position: sticky;
    top: 0;
    z-index: 10;
    border-bottom: 1px solid var(--border-color);
}

.calendar-grid {
    display: grid;
    grid-template-columns: repeat(7, minmax(120px, 1fr));
    grid-auto-rows: 1fr;
    flex-grow: 1;
    min-width: 840px;
    background: var(--border-color);
    gap: 1px; /* Creates grid lines */
}

.calendar-day {
    background: var(--bg-primary);
    padding: 12px;
    transition: all 0.2s;
    cursor: pointer;
    position: relative;
    min-height: 120px;
    display: flex;
    flex-direction: column;
}

.calendar-day:hover {
    background: var(--bg-secondary);
}

.calendar-day.not-current {
    background: var(--bg-secondary);
    opacity: 0.5;
}

.calendar-day.today {
    background: var(--day-today);
}

.day-number {
    font-weight: 600;
    font-size: 0.875rem;
    margin-bottom: 8px;
}

.day-events {
    display: flex;
    flex-direction: column;
    gap: 4px;
    flex-grow: 1;
}

.event-pill {
    font-size: 0.7rem;
    background: var(--event-pill-bg);
    padding: 3px 6px;
    border-radius: 4px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    border-left: 2px solid var(--accent);
    color: var(--text-main);
    max-width: 100%;
}

.event-pill.recurring {
    border-left-color: #f59e0b;
}

/* Overlay Styling */
.overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.4);
    backdrop-filter: blur(4px);
    display: none;
    justify-content: center;
    align-items: center;
    z-index: 2000;
}

.overlay-content {
    background: var(--bg-primary);
    width: 100%;
    max-width: 480px;
    border-radius: 12px;
    padding: 32px;
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    margin: 20px;
}

.overlay-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.overlay-header h3 {
    font-size: 1.25rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: var(--text-main);
}

.add-quick-btn {
    background: var(--accent);
    color: white;
    border: none;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    font-size: 1.5rem;
    cursor: pointer;
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.2s;
    margin-right: 12px;
}

.add-quick-btn:hover {
    background: var(--accent-hover);
    transform: translateY(-2px);
}

.close-overlay {
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    width: 44px;
    height: 44px;
    border-radius: 12px;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    justify-content: center;
    align-items: center;
    transition: all 0.2s;
}

.close-overlay:hover {
    background: #fee2e2;
    color: #ef4444;
    border-color: #fca5a5;
}

.overlay-event-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.event-detail-card {
    padding: 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    background: var(--bg-primary);
    box-shadow: var(--card-shadow);
}

.event-detail-card h4 {
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.event-time {
    color: var(--text-muted);
    font-size: 0.8125rem;
    font-weight: 500;
}

.event-desc {
    font-size: 0.875rem;
    color: var(--text-muted);
    margin-top: 8px;
}

.event-actions {
    display: flex;
    gap: 8px;
}

.delete-btn {
    padding: 6px 10px;
    background: transparent;
    color: #ef4444;
    border: 1px solid #fee2e2;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.delete-btn:hover {
    background: #fef2f2;
    border-color: #ef4444;
}

.edit-btn {
    padding: 6px 10px;
    background: var(--accent);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
}

@media (max-width: 1000px) {
    .app-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: fixed;
        left: -100%;
        top: 0;
        bottom: 0;
        width: 100%;
        max-width: 320px;
        z-index: 1500;
        transition: left 0.3s ease;
    }

    .sidebar.active {
        left: 0;
    }

    .mobile-toggle {
        display: block;
    }

    .calendar-container {
        padding: 64px 16px 16px 16px;
    }

    .calendar-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
}