header {
    display: flex;
    gap: 8px;
}

.course-page .main-ui {
    padding-top: 80px;
    padding-bottom: 40px;
    padding-left: 16px;
    padding-right: 16px;
}

#back-link {
    display: inline-block;
    font-size: 13px;
    color: var(--text-secondary);
    text-decoration: none;
    margin-bottom: 16px;
    transition: color 0.15s;
}

.back-link:hover {
    color: var(--text-primary);
}

.filters {
    margin-bottom: 24px;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.filter-row {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.filter-label {
    font-size: 11px;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    width: 70px;
    flex-shrink: 0;
    padding-top: 7px;
    font-family: var(--font-mono);
}

.filter-chips {
    display: flex;
    align-items: center;
    gap: 6px;
    flex-wrap: wrap;
}

.filter-chips-wrap {
    max-width: 360px;
}

.chip {
    display: inline-flex;
    align-items: center;
    padding: 5px 10px;
    font-size: 13px;
    color: var(--text-secondary);
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    cursor: pointer;
    user-select: none;
    transition: all 0.15s ease;
}

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

.chip input {
    display: none;
}

.chip:has(input:checked) {
    background: var(--accent-black);
    color: var(--bg-color);
    border-color: var(--accent-black);
}

.chip:has(input:checked) small {
    color: var(--bg-color);
    opacity: 0.7;
}

.chip small {
    font-family: var(--font-mono);
    font-size: 10px;
    margin-left: 4px;
    opacity: 0.6;
}

.chip-sm {
    padding: 4px 8px;
    font-size: 12px;
}

.chip-sm small {
    font-size: 9px;
}

#papers-list {
    margin-top: 8px;
}

#papers-list:empty::after {
    content: "No papers found.";
    display: block;
    text-align: center;
    color: var(--text-secondary);
    padding: 32px 0;
    font-size: 14px;
}

#papers-list li {
    cursor: pointer;
}

.paper-code {
    font-weight: 500;
    font-size: 14px;
    flex: 1;
}

.paper-tags {
    display: flex;
    gap: 6px;
    margin-right: 12px;
}

.paper-tag {
    font-family: var(--font-mono);
    font-size: 11px;
    color: var(--text-secondary);
    background: var(--hover-bg);
    padding: 2px 6px;
    border-radius: 4px;
}

.paper-tag-exam {
    min-width: 36px;
    text-align: center;
}

.download-btn {
    margin-left: auto;
    color: var(--text-secondary);
    transition: color 0.15s;
    display: flex;
    align-items: center;
}

.download-btn:hover {
    color: var(--text-primary);
}

li.done {
    opacity: 0.3 !important;
}

li.done .paper-code {
    text-decoration: line-through;
}

.checkbox-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 12px;
    padding: 4px;
    cursor: pointer;
    color: var(--text-secondary);
    transition:
        color 0.15s ease,
        opacity 0.15s ease;
    border-radius: 50%;
}

.checkbox-wrapper:hover {
    color: var(--text-primary);
    background-color: var(--hover-bg);
}

li.done .checkbox-wrapper {
    color: var(--text-primary);
}

#cmd-k-dialog {
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: var(--bg-color);
    color: var(--text-primary);
    box-shadow: none;
    width: 100%;
    max-width: 480px;
    padding: 0;
    inset: 0;
    margin: auto;
    margin-top: 15vh;
}

#cmd-k-dialog::backdrop {
    background-color: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(2px);
}

#cmd-k-dialog:focus {
    outline: none;
}

#cmd-k-dialog #search-area {
    padding: 8px;
    border: none;
}

#cmd-k-dialog #cmd-k-input {
    width: 100%;
    background-color: transparent;
    border: none;
    font-size: 14px;
    font-weight: 400;
    user-select: none;
    padding: 0;
    color: var(--text-primary);
}

#cmd-k-dialog #cmd-k-input:focus {
    outline: none;
}

#cmd-k-dialog #cmd-k-input::placeholder {
    color: var(--text-secondary);
}

#cmd-k-dialog #cmd-k-results {
    min-height: 200px;
    max-height: 300px;
    overflow-y: auto;
}

#cmd-k-dialog #cmd-k-results:empty {
    min-height: 40px;
}

#search-btn:last-child {
    font-family: var(--font-mono);
    font-size: 12px;
}

search-btn span {
    padding: 0;
    margin: 0;
}

#cmd-icon {
    font-size: 12px;
}