:root {
    --bg-main: #f2f3f8;
    --blue-light: #008be3;
    --blue-dark: #1a0088;
    --text-color: #333333;
    --card-border-radius: 12px;
    
    /* Status Color Palette */
    --status-aprobada-bg: #e8f5e9;
    --status-aprobada-border: #2e7d32;
    --status-aprobada-text: #1b5e20;
    
    --status-cursando-bg: #fff3e0;
    --status-cursando-border: #e65100;
    --status-cursando-text: #bf360c;

    --status-regular-bg: #fffde7;
    --status-regular-border: #f57f17;
    --status-regular-text: #f57f17;

    --status-pendiente-bg: #ffffff;
    --status-pendiente-border: #cfd8dc;
    --status-pendiente-text: #757575;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Roboto', sans-serif;
}

body {
    background-color: var(--bg-main);
    color: var(--text-color);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    text-decoration: none;
    color: inherit;
}

/* Header Principal */
.header {
    background-color: var(--blue-light);
    color: white;
    padding: 22px 40px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    box-shadow: 0 3px 10px rgba(0,0,0,0.1);
}

.header h1 {
    font-size: clamp(1.6rem, 3.5vw, 2.5rem);
    font-weight: 300;
    line-height: 1.1;
    letter-spacing: -0.5px;
}

.header h1 span {
    font-weight: 700;
}

.back-btn {
    background: white;
    color: var(--blue-light);
    padding: 10px 20px;
    border-radius: 8px;
    font-weight: 700;
    font-size: 0.85rem;
    text-transform: uppercase;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: transform 0.2s, background-color 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

.back-btn:hover {
    transform: translateY(-2px);
    background-color: #f8f9fa;
}

/* Banner Hero & Estadísticas */
.sub-header {
    background-color: var(--blue-dark);
    color: white;
    padding: 28px 40px;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-between;
    align-items: center;
    gap: 24px;
}

.sub-header-title {
    font-size: clamp(1.4rem, 2.5vw, 2.1rem);
    font-weight: 500;
}

.sub-header-subtitle {
    font-size: 0.95rem;
    opacity: 0.88;
    margin-top: 6px;
}

.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(125px, 1fr));
    gap: 12px;
    width: 100%;
    max-width: 650px;
}

.stat-card {
    background: rgba(255, 255, 255, 0.12);
    backdrop-filter: blur(6px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 12px 14px;
    border-radius: 12px;
    text-align: center;
}

.stat-value {
    font-size: 1.4rem;
    font-weight: 700;
}

.stat-label {
    font-size: 0.72rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    opacity: 0.9;
    margin-top: 3px;
}

.progress-bar-container {
    width: 100%;
    background-color: rgba(255, 255, 255, 0.2);
    height: 8px;
    border-radius: 4px;
    margin-top: 8px;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background-color: #4caf50;
    width: 0%;
    transition: width 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Toolbar de Filtros y Búsqueda */
.toolbar {
    padding: 18px 40px;
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    justify-content: space-between;
    align-items: center;
    background-color: #ffffff;
    border-bottom: 1px solid #e2e8f0;
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

.filters-group {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.filter-btn {
    background-color: var(--bg-main);
    color: #555;
    border: 1px solid #d1d5db;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.filter-btn:hover, .filter-btn.active {
    background-color: var(--blue-dark);
    color: white;
    border-color: var(--blue-dark);
}

.search-box {
    position: relative;
    min-width: 260px;
}

.search-box input {
    width: 100%;
    padding: 8px 16px 8px 36px;
    border-radius: 20px;
    border: 1px solid #ccc;
    font-size: 0.88rem;
    outline: none;
    transition: border-color 0.2s;
}

.search-box input:focus {
    border-color: var(--blue-light);
}

.search-box i {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: #888;
    font-size: 0.9rem;
}

/* Contenedor Principal por Filas */
.main-content {
    padding: 30px 40px;
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 32px;
}

/* Sección Fila por Nivel */
.level-row {
    background: #ffffff;
    border-radius: 16px;
    border: 1px solid #e2e8f0;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.03);
    overflow: hidden;
}

.level-row-header {
    background-color: var(--blue-dark);
    color: white;
    padding: 14px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.level-row-header.electivas {
    background-color: var(--blue-light);
}

.level-row-title {
    font-size: 1.15rem;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 10px;
}

.level-row-badge {
    background: rgba(255, 255, 255, 0.2);
    padding: 4px 12px;
    border-radius: 12px;
    font-size: 0.78rem;
    font-weight: 500;
}

/* Grilla Interna de Tarjetas en la Fila */
.subjects-grid {
    padding: 20px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 16px;
}

/* Tarjeta Informativa de Materia (Solo Lectura) */
.subject-card {
    border-radius: var(--card-border-radius);
    padding: 14px;
    border-left: 5px solid var(--status-pendiente-border);
    background-color: var(--status-pendiente-bg);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
    position: relative;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.04);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    cursor: default; /* Solo Lectura */
}

.subject-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 14px rgba(0, 0, 0, 0.07);
}

.subject-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
}

.subject-code {
    font-size: 0.75rem;
    font-weight: 700;
    color: #555;
    background: rgba(0,0,0,0.06);
    padding: 2px 8px;
    border-radius: 4px;
}

.subject-status-badge {
    font-size: 0.68rem;
    font-weight: 700;
    padding: 4px 10px;
    border-radius: 12px;
    text-transform: uppercase;
    letter-spacing: 0.3px;
    display: inline-flex;
    align-items: center;
    gap: 5px;
}

.subject-title {
    font-size: 0.98rem;
    font-weight: 600;
    line-height: 1.35;
    color: #1e293b;
    margin-bottom: 12px;
}

.subject-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.75rem;
    color: #64748b;
    border-top: 1px solid rgba(0,0,0,0.05);
    padding-top: 8px;
}

/* Asignación Visual por Estado */
.subject-card[data-status="aprobada"] {
    background-color: var(--status-aprobada-bg);
    border-left-color: var(--status-aprobada-border);
}
.subject-card[data-status="aprobada"] .subject-status-badge {
    background-color: var(--status-aprobada-border);
    color: white;
}

.subject-card[data-status="cursando"] {
    background-color: var(--status-cursando-bg);
    border-left-color: var(--status-cursando-border);
}
.subject-card[data-status="cursando"] .subject-status-badge {
    background-color: var(--status-cursando-border);
    color: white;
}

.subject-card[data-status="regularizada"] {
    background-color: var(--status-regular-bg);
    border-left-color: var(--status-regular-border);
}
.subject-card[data-status="regularizada"] .subject-status-badge {
    background-color: var(--status-regular-border);
    color: white;
}

.subject-card[data-status="pendiente"] {
    background-color: var(--status-pendiente-bg);
    border-left-color: var(--status-pendiente-border);
    border-top: 1px solid #f1f5f9;
    border-right: 1px solid #f1f5f9;
    border-bottom: 1px solid #f1f5f9;
}
.subject-card[data-status="pendiente"] .subject-status-badge {
    background-color: var(--status-pendiente-border);
    color: white;
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 16px 20px;
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }

    .sub-header {
        padding: 20px;
        flex-direction: column;
        align-items: flex-start;
    }

    .toolbar {
        padding: 14px 20px;
        flex-direction: column;
        align-items: stretch;
    }

    .search-box {
        width: 100%;
    }

    .main-content {
        padding: 20px 15px;
    }

    .subjects-grid {
        padding: 14px;
        grid-template-columns: 1fr;
    }
}