body {
    margin: 0;
    font-family: 'Segoe UI', Arial, sans-serif;
    background: #181a20;
    color: #e0e0e0;
    transition: background 0.3s, color 0.3s;
}
body.light {
    background: #f5f6fa;
    color: #222;
}
header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
    background: #23263a;
    color: #fff;
    box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
body.light header {
    background: #fff;
    color: #23263a;
}
.header-buttons button {
    margin-left: 1rem;
    padding: 0.5rem 1rem;
    border: none;
    border-radius: 6px;
    background: #353a50;
    color: #fff;
    cursor: pointer;
    font-size: 1rem;
    transition: background 0.2s;
}
body.light .header-buttons button {
    background: #e0e0e0;
    color: #23263a;
}
.header-buttons button:hover {
    background: #4b5170;
}
.tab-nav {
    display: flex;
    background: #23263a;
    padding: 0.5rem 2rem;
    gap: 1rem;
}
body.light .tab-nav {
    background: #fff;
}
.tab-btn {
    background: none;
    border: none;
    color: inherit;
    font-size: 1rem;
    padding: 0.5rem 1.5rem;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: border-color 0.2s;
}
.tab-btn.active {
    border-bottom: 2px solid #4b8cff;
    color: #4b8cff;
}
main {
    padding: 2rem;
    max-width: 900px;
    margin: auto;
}
.tab-content {
    display: none;
}
.tab-content.active {
    display: block;
}
.materias-header {
    margin-bottom: 1rem;
}
#add-materia {
    background: #4b8cff;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 0.5rem 1.2rem;
    font-size: 1rem;
    cursor: pointer;
}
#add-materia:hover {
    background: #3570c7;
}
#materias-list {
    list-style: none;
    padding: 0;
}
.materia-item {
    background: #23263a;
    margin-bottom: 1rem;
    border-radius: 8px;
    padding: 1rem;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
body.light .materia-item {
    background: #fff;
}
.materia-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.materia-actions button,
.grupo-actions button {
    margin-left: 0.5rem;
    background: #4b8cff;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 0.3rem 0.8rem;
    font-size: 0.95rem;
    cursor: pointer;
}
.materia-actions button:hover,
.grupo-actions button:hover {
    background: #3570c7;
}
.grupos-list {
    list-style: none;
    padding: 0.5rem 0 0 1rem;
}
.grupo-item {
    background: #353a50;
    margin-bottom: 0.5rem;
    border-radius: 6px;
    padding: 0.7rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
body.light .grupo-item {
    background: #e0e0e0;
}
.sortable-list {
    list-style: none;
    padding: 0;
    margin-bottom: 2rem;
}
.sortable-list li {
    background: #23263a;
    margin-bottom: 0.5rem;
    border-radius: 6px;
    padding: 0.7rem 1rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    cursor: grab;
    transition: box-shadow 0.2s, background 0.2s;
}
.sortable-list li.dragging {
    opacity: 0.5;
    box-shadow: 0 0 8px #4b8cff;
}
.sortable-list li.drag-over {
    background: #353a50;
    box-shadow: 0 0 8px #4b8cff;
}

body.light .sortable-list li {
    background: #fff;
}
.sortable-list .priority-actions button {
    background: #4b8cff;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 0.2rem 0.7rem;
    font-size: 0.9rem;
    cursor: pointer;
}
.sortable-list .priority-actions button:hover {
    background: #3570c7;
}
.generator-options {
    margin-bottom: 1.5rem;
    display: flex;
    gap: 1rem;
}
.generator-options button {
    background: #4b8cff;
    color: #fff;
    border: none;
    border-radius: 6px;
    padding: 0.5rem 1.2rem;
    font-size: 1rem;
    cursor: pointer;
}
.generator-options button:hover {
    background: #3570c7;
}
.schedules {
    display: flex;
    gap: 2rem;
    flex-wrap: wrap;
}
.schedule-table {
    flex: 1 1 350px;
    background: #23263a;
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 2rem;
}
body.light .schedule-table {
    background: #fff;
}
.schedule-table h3 {
    margin-top: 0;
}
table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 1rem;
}
thead th, tbody td {
    border: 1px solid #353a50;
    padding: 0.5rem;
    text-align: center;
}
body.light thead th, body.light tbody td {
    border: 1px solid #e0e0e0;
}
.schedule-details {
    font-size: 0.95rem;
    color: #b0b0b0;
}
.modal {
    position: fixed;
    top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(0,0,0,0.6);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}
.modal.hidden {
    display: none;
}
.modal-content {
    background: #23263a;
    color: #fff;
    padding: 2rem;
    border-radius: 10px;
    min-width: 320px;
    max-width: 90vw;
    box-shadow: 0 4px 24px rgba(0,0,0,0.2);
    position: relative;
}
body.light .modal-content {
    background: #fff;
    color: #23263a;
}
.close {
    position: absolute;
    top: 1rem;
    right: 1rem;
    font-size: 1.5rem;
    cursor: pointer;
    color: #4b8cff;
}
.close:hover {
    color: #3570c7;
}
input, select {
    padding: 0.5rem;
    border-radius: 6px;
    border: 1px solid #353a50;
    background: #181a20;
    color: #e0e0e0;
    font-size: 1rem;
    margin-bottom: 1rem;
    width: 100%;
    box-sizing: border-box;
}
body.light input, body.light select {
    background: #fff;
    color: #23263a;
    border: 1px solid #e0e0e0;
}
form label {
    display: block;
    margin-bottom: 0.3rem;
    font-weight: 500;
}
form {
    margin-bottom: 0;
}
@media (max-width: 700px) {
    main {
        padding: 1rem;
    }
    .schedules {
        flex-direction: column;
        gap: 1rem;
    }
    .schedule-table {
        padding: 0.5rem;
    }
}