/* --- Light & Dark Mode Color Variables --- */
:root {
    --primary-bg: #f8f9fa;
    --content-bg: #ffffff;
    --header-bg: #343a40;
    --header-text: #ffffff;
    --table-header-bg: #e9ecef;
    --border-color: #dee2e6;
    --text-color: #212529;
    --accent-color: #007bff;
    --shadow-color: rgba(0,0,0,0.05);
}

html.dark-mode {
    --primary-bg: #121212;
    --content-bg: #1e1e1e;
    --header-bg: #2a2a2a;
    --header-text: #e0e0e0;
    --table-header-bg: #343a40;
    --border-color: #495057;
    --text-color: #e0e0e0;
    --accent-color: #0d6efd;
    --shadow-color: rgba(0,0,0,0.2);
}

/* --- Base Styles --- */
body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    margin: 0;
    background-color: var(--primary-bg);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

header {
    background-color: var(--header-bg);
    color: var(--header-text);
    padding: 1rem 2rem;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    position: relative;
}

h1, h2, h3 { font-weight: 500; }
h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

main { padding: 1.5rem; max-width: 1200px; margin: 0 auto; width: 95%; }
footer { text-align: center; padding: 1rem; font-size: 0.8rem; color: #6c757d; }

/* --- Theme Toggle --- */
#theme-toggle {
    position: absolute;
    right: 20px;
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.5rem;
    background: transparent;
    border: none;
    cursor: pointer;
    color: var(--header-text);
}

/* --- Controls, Tabs, Filters --- */
.controls, .filters-container, #schedule-display {
    background-color: var(--content-bg);
    border-radius: 8px;
    box-shadow: 0 2px 4px var(--shadow-color);
    margin-bottom: 1.5rem;
    padding: 1.5rem;
}
.controls { display: flex; flex-wrap: wrap; gap: 1rem; align-items: center; }
.filters-container { display: flex; flex-wrap: wrap; gap: 2rem; }

.view-tabs { width: 100%; border-bottom: 1px solid var(--border-color); }
.view-tabs button {
    padding: 0.7rem 1.2rem;
    font-size: 1rem;
    border: none;
    border-bottom: 3px solid transparent;
    background-color: transparent;
    cursor: pointer;
    color: var(--text-color);
    opacity: 0.7;
    margin-bottom: -1px;
    transition: all 0.2s;
}
.view-tabs button:hover { opacity: 1; border-bottom-color: #adb5bd; }
.view-tabs button.active { color: var(--accent-color); border-bottom-color: var(--accent-color); opacity: 1; }

.control-group { display: flex; flex-direction: column; gap: 0.5rem; }
.date-selector-wrapper { display: flex; align-items: center; }
.date-selector-wrapper button {
    padding: 0.5rem 0.8rem;
    font-size: 1rem;
    background-color: var(--table-header-bg);
    border: 1px solid var(--border-color);
    cursor: pointer;
    color: var(--text-color);
}
#prev-day-btn { border-radius: 4px 0 0 4px; }
#next-day-btn { border-radius: 0 4px 4px 0; }
input[type="date"] {
    padding: 0.4rem;
    border: 1px solid var(--border-color);
    border-radius: 0;
    font-size: 1rem;
    background-color: var(--content-bg);
    color: var(--text-color);
    color-scheme: dark; /* Helps with date picker in dark mode */
}
html.dark-mode input[type="date"] { color-scheme: dark; }

.filter-group legend { font-weight: 600; margin-bottom: 0.5rem; }
.checkbox-toggles { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.checkbox-toggles input[type="checkbox"] { display: none; }
.checkbox-toggles label {
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--border-color);
    border-radius: 20px;
    cursor: pointer;
    background-color: var(--primary-bg);
}
.checkbox-toggles input[type="checkbox"]:checked + label {
    background-color: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* --- Schedule Display & Badges --- */
#display-heading { margin-bottom: 1rem; border-bottom: 2px solid var(--border-color); padding-bottom: 0.5rem; }
table { width: 100%; border-collapse: collapse; margin-top: 0.5rem; }
th, td { padding: 0.8rem 1rem; text-align: left; border-bottom: 1px solid var(--border-color); vertical-align: middle; }
th { background-color: var(--table-header-bg); }
td ul { margin: 0; padding: 0; list-style-type: none; }
td ul li { margin-bottom: 4px; }
.pgy-badge { display: inline-block; padding: 0.2em 0.5em; font-size: 0.75rem; font-weight: 700; border-radius: 0.25rem; color: #fff; margin-left: 8px; }
.assignment-tag { display: inline-flex; align-items: center; padding: 0.2em 0.6em; font-size: 0.9em; border-radius: 4px; }
.assignment-tag .emoji { margin-right: 5px; }

/* --- System Preference Dark Mode --- */
@media (prefers-color-scheme: dark) {
    :root:not(.light-mode) {
        --primary-bg: #121212;
        --content-bg: #1e1e1e;
        --header-bg: #2a2a2a;
        --header-text: #e0e0e0;
        --table-header-bg: #343a40;
        --border-color: #495057;
        --text-color: #e0e0e0;
        --accent-color: #4dabf7;
        --shadow-color: rgba(0,0,0,0.2);
    }
}